Bromeliaceae and Dangerous Plants: Adaptation, Climate Change and Gardening in Portland

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I don’t know what this Bromeliad is, but it is statuesque, the inflorescence reaching well above my head. I took this shot next to Burl’s ‘chateau’ at Rare Plant Research just south of Oregon City. He moves a lot of tropical exotics in and out of his greenhouses every year. This is what a lot of people think of when they picture a Bromeliad.

I awaken and come down stairs at about 7:00 am…it’s a warm 66ºF outside.  I was up late last night, until after 12:00 am, keeping the air flowing through downstairs in an attempt to cool the house.  This is on the warm side for us here in the summer.  On rare occasions our lows can drop to as high as the low 70’s…such temps tend to occur more frequently in more recent years when ‘heat lows’ settle in around us and we suffer through ‘heat alerts’, whenthe air stagnates and turns ‘brown’ and we can become caught in one of those cycles of days where our highs remain in the upper 90’s and low 100’s.  Our all time record high of 107º, in August of 1981, was during such a cycle that I had the privilege of experiencing as I was here in Portland visiting a friend and attending my brother’s wedding.  On the 6th it hit 99º.   The high rose the next day to 102º, 105º on the 8th, 104º the next, 107º on the 10th, the humidity at 15%, then cooling to 97º on the 11th.  I remember taking turns trying to cool ourselves, without any air conditioning, submerging in a tub of tepid bath water,

As our climate warms such temperatures are becoming more common.  In June of ’15 we recorded 9 days with highs of 90º and above, 21 over 80º, the warmest June on record, a month that has historically been a ‘spring’ month in terms of its variability.  That month saw several other records fall: consecutive days without rain, previously 18 now 25, and warmest June night, once 68º now 71º.

[We are currently, as of July 29, ‘working’ on day 42 with zero precipitation…and none in sight! As most gardeners know this does not ‘balance out’ our heavier than normal accumulation thus far this rain year.  Plants need water while they’re in active growth, not dormant.  We’ve hit 100ºF once, it was 102º on June 25, had 3 days at 90º or better and 8 over 80º, a fete we almost duplicated in May this year. In July we are shaping up to be quite normal averaging around 2 degrees F over our normal high of 81º.  The forecast, however, is alarming.  We are projected to have two days in the next week that could break our all time high record, the forecast calling for 109ºF.  Climate change is not about today or tomorrow, its the big picture, the extremes and patterns, the changes to the margins, what we and what lives here has to stretch to accommodate.]

It has not been uncommon historically to have many June days locked into a cool drizzly pattern with highs stuck in the ’50’s, the maritime influence still strong and retaining its hold over the daily weather.  Such cool/wet June’s are so frequent here that there is a commonly used term for such a pattern, ‘June-uary’! a pattern that is remarkably like many of our actual January days, such can be the effect of the cold north Pacific 90 miles to our west.  People used to joke about how summer in Portland begins on the fourth of July.  We are warming.

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These two graphs of the fateful, for my Fascicularia pitcairnifolia, winter of ’13-’14. Showing our typical, erratic, spiking pattern of temperatures with two abnormally cold periods. The lower graph shows the years accumulated percipitation, 5″ below ‘normal’. In contrast, through July of our current rain year, we have received around 57″ in inner SE Portland, about 23″ over normal, or 67% above normal. The time period is our ‘rain year’ measured from Oct.1 – Sept.30 beginning in the fall after our typical summer ‘drought’ period.

This is probably part of the reason that i’ve found myself drawn to plants from historically  warmer climates.  Experiencing increasingly warm weather days, many once well adapted native species can find the climate ‘welcome mat’ less hospitable than it has previously been. Shifts in average temperature, higher peak temps, have a cumulative effect on living communities in which little shifts can potentially lead to the loss of marginal populations which can in turn have a greater or lesser effect on other species who have depended on these for food or had symbiotic or commensal relationships with them.  All relationships are complex.  Growing plants from other climes and regions gets you looking more at why there and not here.  What kind of changes are necessary for new, previously exotic species, to find a new home here filling niches left by those not tolerant of our changing conditions.  Climate change aside there are still the hugely altered growing conditions of the city, its heat island and drastically compromised soils, the introduction of so many weedy and invasive species and the surrounding regional landscapes, either put directly to human use as agricultural lands, developed more directly for human occupation…or simply heavily disturbed ‘transition’ lands, serving no direct purpose, but forever changed.  I write of this more directly elsewhere.

What fairer weather plants have I been thinking about?  family, Bromeliaceae, a plant family, containing 51 genera and around 3,500 species, none of which are represented here in our native flora, one of the last families most gardeners might think about when considering plants for the Pacific Northwest.  Typically these are thought of by most of us living in temperate climates as ‘wet’ tropicals,  but the family has proven adaptable and includes species that can grow well beyond the tropical and sub-tropical regions of the world to where they’ve been introduced into Mediterranean regions, proliferating in many California gardens as far north as the Berkley area.  I grow one species, in a ‘protected’ spot, in the ground, in my own garden.

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A Few Words On Vegetative Armament, Plant Defense and Recurved Spines: Jaws that Bite, Claws that Tear

I spent almost 30 years working in Parks here, in the ‘field’.  My tasks were many and aligned with the landscapes and properties under my charge.  Invariably, much of my time was spent with the control of weeds and invasive plants.  In particular I want to talk a little about Himalayan Blackberry, a Rubus sp. that has been assigned several species names over the years, most recently Rubus armeniacus, that I learned as R. discolor.  I worked in north and northeast Portland and later on in Parks in Downtown and the West Hills.  In some of these parks this plant covered many thousands of square feet, if not acres.  I battled it at Kelley Point and Pier Parks where it occurs in large patches, in forest openings in Washington Park and stands of it on the steep bank below the Eastbank Esplanade and the west bank below the Riverplace Esplanade where it constantly tried to spread into more desirable vegetation.  The conditions at each site shaped my strategy in a way I thought would be most effective and safe, both for me and the surrounding landscape.

I can remember many times ‘wading’ into a mature stand of Blackberry 8’-15’ tall, covering several thousand sq.ft. in a ‘patch’, with my gas powered hedge trimmer, slicing and dicing, as I moved along its edge and ventured into its mass.  It was a workout to say the least, cutting with broad strokes low, medium and high, horizontally, vertically and diagonally, left and right.  If the area was very large, this was a winter job, heavily protected in coveralls, chaps, gloves, boots, a helmet and face shield in an attempt to armor myself against the plant’s defenses.

(Later, in late Spring or early Summer, I would return to apply a broad-leaf selective herbicide on the much lower and more compact regrowth, reducing the danger of its drifting off target, damaging non-target species and making it safer for me.)

The tactics involved cutting it as I went, into manageable pieces, that would drop where they were cut without undermining the ‘structure’ in such a way that the whole thing might ‘collapse’ on top of me, each reverse curving barb perfectly positioned to bite into clothing or my skin if presented.  Of course this would happen anyway.

Other times, when the particular ‘incursion’ was much smaller or growing within desirable plants, I might press my way in to reach the bramble’s base, or where it may have tip layered, and cut the stem back close, if I couldn’t pull or easily dig it out, immediately treating it with a concentrate, using a squirt bottle, minimizing the chemical used in a directed and precise way.  This method could bring you into close contact as well with the business end of the plant’s barbs.

Some plants are merely spiny…they stab when you get to close and withdraw as you back away, not this particular Rubus.  You learn very quickly that once ‘engaged’ by the Blackberry, a quick and hasty retreat is a mistake, as the recurved ‘claws’ of the beast sink into the soft tissue behind your ear, your neck, arm or leg.  What is required is calm.  The claws of big cats are recurved to help them hold their prey preventing escape.  The effect in the vegetable world is similar.  So, think!  You set down the hedge trimmer after shutting it off.  Evaluate the severity of the attack, the critical points of contact, while still engaged, and then thoughtfully and dispassionately, move the aggrieved limb or flesh, forward, into the mass of the plant, to release the barb’s hold while lowering, twisting or lifting the offending cane away…moving your body in the opposite direction once the claw’s hold is released.  This action is complicated when there are several simultaneous points of contact in front of you, to your side and even behind you.  When cutting, it is absolutely essential that you anticipate what effect your cut will have on the mass of bramble above you, how and in which direction it will collapse.  Blood will be lost.  If there are too many points of contact, attack, it can get ugly in a hurry.

Recurved spines are not unique to Blackberries…fortunately they are less common than the straight spines so common to many other species at least among the plants we use in horticulture.  They occur along the leaf margins of many Agave spp. and are very common on many members of the Bromeliad family.  Interestingly, those plants we commonly call ‘carnivorous’ the Sarracenia spp. and Darlingtonia, don’t have these, they pursue an alternative strategy.  Some of the Bromeliads can be merciless with anyone or thing that gets too close.  It wasn’t that long ago that I didn’t grow any of these plants, I’d even eliminated Roses from my own garden though that decision had nothing to do with their thorns.  Among these plants, Agaves came first for me.

Their attraction was architectural and my curiosity was piqued by the whole desert and monsoonal rain pattern thing.  Before too long I had begun adding members of the Bromeliad family, staying away from Cactus as my limited knowledge and experience with Opuntia and Cylindropuntia, two genera renowned for their ‘glochids’, the tiny hairlike, barbed spines at the base of their more obvious spines.  The glochids could ‘bite’ and keep biting, from seemingly incidental contact, and they seem to do this even when the gardener, or visitor, has avoided contact with the much more visible projecting spines.  The ‘spineless’ Opuntia‘s still have the troublesome glochids giving the ignorant an unearned feeling of safety.  At this date I have slightly relaxed my Cactus ‘ban’ and have tried a couple of the ‘fish-hook’ type cactus, which are glochid free and have ‘bent’ tips at the ends of their spines reducing the incidence of casual punctures.

Botanist often argue that these various kinds and sizes of spines, of ‘armament’, are defensive, protecting the plants from the many grazers and browsers…but, I have to ask, is that all it is?  Why thorns, sharp little bristles, those irritating little hairs that some plants have and…why glochids.  God, why glochids?  Why not just toxins and chemical irritants?  Is it really only to deter ungulates and browsers?  Are these vicious hooked barbs the only thing that have saved so many Bromeliads from oblivion?  Are they otherwise so darn tasty that all of the grazers, gnawers and chewers would decimate them and leave us only with grasses and sweet soft herbaceous plants?  I doubt it.  Why haven’t any grasses developed such defensive barbs?  True, grasses have the ability to ‘bounce back’ from normal grazing ‘pressure’ and the are prodigious seeders and many, especially when ‘cropped’ down, spread move thickly, vegetatively, across the ground.  What about all of those  woody species without any ‘weaponry’ whatsoever to defend themselves and future generations? that are slow to reproduce?  and, when they do, do so sparingly?   Are these little ‘eruptions’ and exclamation points along a Bromeliad and Agave leaf’s margin just some little quirk of botanical fate?  Were the spines of Rubus spp. really ‘created’ by the relentless chomping of herbivores?  Will Hawaii’s thornless Rubus spp. develop similar spines if the exotic goats now there are left on their own to munch what they will?  Is such spininess more common and aggressive on species that take years to reach maturity?  If I did a survey would it show that slow growing plants, plants that never grow beyond the reach of local ‘predatory’ herbivores, are more heavily defended than others?  Are most plants that utilize the CAM photosynthesis pathway, which contributes to some plants being slow growing, likewise heavily defended?  Bromeliads are such CAM plants, so are Agave.  How have the grasses and sweet clovers survived so long?  Are they just god’s chosen sacrificial children? able to recover from regular attack?  Do these barbed and spined plants have some inherent value that the world can’t simply live without?  So many questions.

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This still emerging Eryngium agavifolium, at this stage, looks more like it could be some kind of Bromeliad than an Agave. Though it looks vicious you and your baby soft skin are much safer around it than similarly barbed Bromeliads.

Whatever the reason for their existence, such marginal armament, is both a deterrent and an attractant to gardeners.  The architectural forms of many of these arcing, rosette growing plants, appeals to many of us.  Their spines, straight and recurved, serve as repeated decorative motifs that we find beautiful, natural creations, precise and perfect, that would take skill and concentration for us to create on our own.  Such plants also ‘demand’ our respect and do not ‘suffer fools gladly!’  These are qualities many of us admire.

For us gardening in the maritime Pacific Northwest, desert, tropical and sub-tropical plants tend not to be plants for novices.  They are more of an acquired taste here, that come with maturity, experience, I like to think, or…I suppose it could be a very specific type of ‘dementia’ some gardeners can be subject to.  Why does an otherwise intelligent, sane, person, start growing plants that can stab, rake and otherwise bloody them, just as their skin is beginning to thin?  Despite our best efforts our skin becomes more fragile, thinning, and much more subject to damage as we age.  Now, when I lift a pot of Hechtia ‘Texas Red’ to set in a tray to bottom water it, it is all too easy to inflict little tears to the backs of my hands and forearms because of the stiff barbed foliage that reaches down near the pot’s sides. I divided a similarly structured Dyckia ‘Red Devil’ a few years ago…there is no give in these plants and each has the ability to grab and hold.  Just getting the stiffer of some of these out of their pot is a challenge.  It would seem that Bromeliaceae, have evolved their structure to frustrate and fend off would be gardeners, at least those species that are stiffer leaved and more aggressively barbed.

Bromeliaceae: Welcome to the Family

Map_of_the_Guiana_shieldToday’s Bromeliads can be traced genetically back 70 million years to the Guiana Shield of South America, a ‘craton’, composed of incredibly dense base rock material from the Earth’s mantle, heaved up through the crust, which is, even in geological terms, very slow to erode.  South of this craton, is a huge basin, that has twice been a huge inland sea, some will argue whether it was freshwater or salt, which has become, for the last several million years at least, the Amazon Basin containing the huge river of the same name.  Three of these cratons comprise much of the continent of South America one of which defines the Basin’s southern border, underlying the Brazil Highlands.  The Guiana Shield provides the ‘foundation’ for most of the northern coast of South America, extending westerly from French Guiana, across Surinam, Guyana and most of Venezuela including a portion of northern Brazil.  Sometimes geologists include part of Colombia.  This area was a lowland tropical jungle, with similar conditions to the present day Amazon basin, where early Bromeliads flourished as terrestrial C3 plants.  The Shield had not yet pushed up to form the Venezuelan Highlands further dividing the continents of North and South America.

This separation of North from South America and the uplift of the Guiana Shield set the stage for the development of today’s Bromeliads.  Genetic studies show, thus far, that the family was quite stable for some 51 million years, up until around the time that the Andes began to push up, (there is no agreement as to when the Andean uplift occurred, different camps arguing variously for dates from 15 – 30 million years ago.) closing the last lower elevation avenue for genetic material to move north and the time that the Amazon established its current form.  This effectively divided the Family from any more intermixing.  What was to the north would stay and stabilize, changing independently to the conditions extant while the genetic material to the south responded in it own way to its varied terrain and conditions.  The land’s of the Shield transformed drying as they heaved upward.  The Andes became a major factor in the continent’s climate, containing much of the precipitation, brought in by the predominant trade winds from the Atlantic, to the huge basin and the eastern side of the mountains while simultaneously creating an extensive ‘band’ of aridity along much of the Andes’ western flank and interior.  (It is also believed that prior to the Andean uplift that the Amazon flowed westerly to the Pacific!)

Bromeliads began invading drier areas in Central and South America roughly 15 million years ago.  The group underwent a process of major adaptive radiation involving the repeated evolution of epiphytism, CAM photosynthesis, impounding leaves, several features of leaf and trichome anatomy, an accelerated rate of ‘speciation’ and the creation of new genera.  Today there are arguably eight sub-families, an expansion beyond the former 3, based on morphological studies alone, according to botanists who study the Family.  Two of the original sub-families Bromelioideae and Tillandsioideae remain, largely unchanged, as they have proven to be monophyletic with a linked ancestry.  Pitacairnioideae, however, was determined to be paraphyletic, being more of a genetic hodge-podge and so was broken down into 6 other sub-families.

Much of the process of speciation, that began in earnest 15 million years ago, was through the process of adaptive radiation, an evolutionary biology term for those periods when significant environmental changes occurred making new resources available, creating new challenges, or opening new environmental niches.  Species respond to these changes exhibiting physical, morphological, changes, often to the degree of forming entirely new species.  As a group the family began to shift from being terrestrial plants, rooted and growing in the soil, to epiphytes, attached to and dwelling on trees.  Over 1,800 species in the family are epiphytes, using their roots to anchor themselves to other plants, without parasitizing the supportive host plant, gathering their water and nutrients via their above ground structures from the water and decay around them.  Many others are lithophytes, anchoring themselves to rock.  One way that Bromeliaceae have evolved to these environments is by altering their basic rosette form into one with impounding leaves, their leaves emerge, without petioles, tightly overlapping, forming a ‘cup’ in the center of each rosette in many species, sometimes substantial in size. This structure ‘funnels’ water that strikes their top surface down into the crown, in many cases capturing and holding it.  This structure is less pronounced in most terrestrial Bromeliads which instead funnel the collected water to their absorbent roots.   Many epiphytes do the same with fallen organic matter.  These are self limiting structures capable of holding only so much depending largely on regular rain and/or cloud condensate to meet their needs.  If there is not enough on a frequent schedule these plants will decline and possibly die.

Many of these epiphytic Bromeliads, like hundreds of other epiphytes, including many Orchids, trap organic ‘litter’ as well, which provides food for resident invertebrates.  Others utilize their roots to help retain organic matter.  Not suprisingly, many plants in this group provide ‘homes’ for many other animal species, generally invertebrates, within their ‘cups’ forming ‘local’ biotic communities.  Over 300 animal species are found no where else but on and in these epiphytic and lithophytic plants.  These animals, in return, provide a source of more nitrogen for the plants.  (If this seems odd to you know that in our own local regions several species of mosquito spend there larval stages in the water held in hollows and ‘cups’ amongst the branches and hollows of trees as revealed by canopy studies of trees like Coast Redwood and Douglas Fir, even Big Leaf Maple, some of which are very specific to these limited environments.  Think of our ubiquitous Licorice Ferns and several species of Moss and Lichen. This group can also include higher plants including various angiosperms or flowering plants.)

In the epiphytic species, within the Tillandsiodeae sub-family, which include the ‘Spanish Moss’ of the American South, these Bromeliads lack the impounding leaves and cups and rely instead on ‘trichomes’, little scales or hair-like structures on the leaves surface, through which the plants take up the water.  These modifications work together and are expressed to a greater or lesser degree in the many species members.  Across the Venezuelan Highlands and the many wetter/warmer valleys and canyons of the northern Andes, in ‘cloud forests’ of Central America, and as far north as Virginia in our South, many of these epiphytic Bromeliads can be found where frequent rains and/or condensate from clouds and/or fog, regularly replenish their needed moisture.

Other Bromeliads took a different pathway and have become very successful in arid, even desert, landscapes.  Some of these, like the Puya spp., populate arid western regions of the same Andes Mountains up into southern Central America.  These are terrestrial plants, relying on their roots to find the moisture that they need.  Possessing a very similar rosette structure, often including their impounding leaves, these plants funnel the infrequent, and seasonal, precipitation they get into their crowns and root structures where they can take it up, a strategy very similar to Agave and Aloe which grow under similar conditions.

Over the course of millions of years, as the highlands pushed up, as the Andes formed, Bromeliads adapted to the higher, drier, climates that had come available transforming their metabolism to what we now identify as the CAM photosynthetic pathway.  These plants utilize solar energy captured in the daylight hours, transforming it into ‘ATP’, a metabolite that provides ready energy for other chemical reactions, working as a kind of biologic ‘battery’ that can be charged, spent and recharged, as do all photosynthetic plants, but this time producing the organic compound, crassulacean acid, ‘storing it’ until nightfall, when leaf stomata open allowing in the CO2, then completing the process transforming it into the carbohydrates and manufacturing the other metabolites that the plant later uses to power its cell growth and build its needed tissues and structures.  In CAM plants these two stages are separated over time effectively and greatly lowering water loss by the plant, minimizing the effects of high ambient temperatures, but, in the process, greatly slowing the overall growth of the plant.  C3 plants (Worldwide the most commonly utilized ‘pathway’, produces a 3 Carbon molecule as an intermediate step instead of Crassulacean Acid, or the 4 Carbon molecule utilized in the intermediate C4 process.) grow more rapidly, wasting considerable water in the process as well as energy through the less controlled respiration, or oxidation, that can occur within the plant when the processes can occur simultaneously, breaking down some of the carbohydrates, that the plant, has previously produced.  C4 plants, thought also to be an adaptation to drier conditions, separate the internal chemical processes physically in such a away that, oxidation, respiration losses, are minimized and are most commonly found in dryland grasses.  CAM is the most water efficient pathway. (See previous postings for a more detailed description of these alternate forms of plant metabolism.)

Succulents or not? and Drought Response

Having described Bromeliads as water thrifty plants that utilize the CAM photosynthetic pathway, I need to say that this does not make them succulents.  Most succulent plants aren’t epiphytic.  Some are lithophytic like the Dudleya that populate some of our west coast rocky points and cliffs.  I’m not sure if Dudleya have the structures or ability to take moisture from the air or if they, like terrestrial plants, depend on their roots for water uptake.   Succulents come from low water areas, often desiccating, environments and, like Bromeliads, utilize the CAM pathway.  Succulents also utilize other strategies to address drought with their capacity to store water within their tissues, a thick cuticle and or other adaptation to their epidermis to reduce water loss and having shallow root systems able to absorb water from even light, non-drenching showers.  All plants contain water within their cells, tissues and, in those that have them, being moved through themselves ‘freely’ within their vascular systems.  Plants that are considered succulents have the capacity to ‘store’ water for later use when it becomes too limited in their surrounding soil.  This water tends to be ‘bound’ within the plant in the form of ‘gels’ which is water bound to complex proteins in the plant  and can hold a great deal of water until conditions change within and a signal is sent to release it.  This is not simply an on/off switch within the plant.  The need is very ‘localized’ within the plant.  Many plants commonly recognized as succulents occur within the Crassula (this is the group of plants within which researchers first identified the CAM pathway), Cactus, Agave and Euphorbia families, among many others.  They occasionally occur as woody plants like the Australian Bottle Tree, Brachychiton rupestris and the genus Pachypodium, but none of the Bromeliads are succulents.

Succulents have thickened leaves and/or stem tissues, some include root structures as well, that can hold water that is not being actively utilized metabolically to enable and support growth, nor is it being moved directly to cells where it can be ‘immediately’ used in this way.  During low water periods it can be moved internally to where it ineeded resulting in a shrinking or withering of these leaf and stem tissues, as internal organic structures, likely proteins, release it, when the drought period is long enough.  In wilting, plant cells and tissues, begin to dry.

[Some species, typically those C3 plants coming from wet climates, can wilt in response to heat if it is too high for them to carry on with their growth processes.  Their metabolic processes can be shut down directly because of ambient temperatures that are too high.  This begins to happen in most plants by the time 90ºF is reached.  The addition of water to such plants will not help them and may in fact lead to their rotting and the promotion of fungal diseases.  What these plants need are lower temperatures.]

 Under-hydrated plants will begin to wilt if they have leaf structures subject to it.  Many succulents don’t have leaves, or have leaves that are extremely modified, minimizing their water loss from their surfaces, while in others their leaves contain water storage tissue.  Water serves a structural function within the cell as well as its vital metabolic functions. Any plant can tolerate water ‘scarcity’ only to a point.  If it goes too far or extends too long, the tissues ‘permanently wilt’ and its cells are physically or structurally damaged.  These will not revive with the addition of water.  When this point is reached, cell structure collapses, and the cell dies.  Succulents can also wilt and die in extended drought, but their capacity for it is much longer due to their water storage ability…and their ability to call on those reserves.  Some deciduous plants have the ability to enter drought dormancy and they do this in part by purposely dropping their leaves.  They are genetically adapted to this and are not unduly stressed by it.  Plants that don’t possess this capacity will attempt to regrow/replace all of the leaves and other desiccated tissues it has suffered, leading to more stress, weakening it going into its winter/cold dormant season.  For many plants this forced defoliation may be enough to kill the plant out right.

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This was my Agave ‘Sharkskin’ last summer. A monocarpic succulent, Agave draw on their moisture stores when they literally erupt into flowering, drawing moisture from their leaves while utilizing their stores of carbohydrate. While this plant is ‘not’ drought stressed you can see what happens to the leaves as they lose moisture shrinking and distorting them.

Succulents are able to withstand extended dry periods and recover without significant tissue loss unless the drought period is beyond its capacity.  When drought stressed these plants begin to draw on their reserves, as long as they are available.  They still require water.  Drought tolerant does not mean a plant doesn’t need water, only that it can operate with it at relatively infrequent or low levels of availability, as long as it is available in adequate amounts so that it can replenish itself…like any plant.  Drought tolerance is the ability of a plant to ‘bridge’ the periods of low water availability a particular species has adapted too.  One plant, succulent or not, may be ‘drought tolerant’ in one setting, but not in another drier setting.  Some Bromeliads like Puya and Hechtia can be extremely drought tolerant because of their adaptations….They just aren’t succulents.

Bromeliads’ above ground structures are primarily leaves.  With a few exceptions they have no significant stem tissues to ‘hold’ water even if they could.  Their leaves are relatively thin in section and tend to be more ‘rigid’ then those of many plants.  They regulate their water use metabolically by utilizing the CAM pathway.  They cannot ‘swell’ with ‘extra’ water, forming storage ‘gels’ within their tissues, nor ‘shrink’ when it is drawn away for plant use.  All of the water within the plant, intra- and extra-cellular, is necessary for the healthy function of the plant.  Rigid leaf structures are often found on drought and very cold tolerant plants, like the sclerophyll native to chaparral and some step regions, but not always.  As a group the family is intolerant of significant or sustained freezing temperatures.  Cold hardiness depends on more than a plant having rigid tissues…but, many terrestrial Bromeliads are quite drought tolerant relying on their water ‘frugality’, their significant and active root systems and, in some cases, the thick, tough epidermis of arid terrestrial species.  These possess the scale like, trichome structures, that in their case, protect them from the burning and drying of direct and intense sunlight.  Their rigidity does help provide the structural integrity they need to both ‘defend’ themselves as I discuss elsewhere and, for those that are epiphytic and have impounding leaves, aid their ‘ability’ to hold water within the cups formed by their rosettes.

Puya

Puya are native to the arid portions of the Andes and South American western coastal mountains.  (Oddly, two species are found in dry areas of Costa Rica.) My Puya chilensis, is native to the arid coastal mountains of Chile where they share space with other sclerophyllous plants, all characterized by their small, evergreen, stiff leaves.  Interestingly it can be found growing near the endangered palm, Jubea chilense and a bamboo, Chusquea cumingii.  This area is sandwiched between the Atacama Desert to its north and the Lakes District to its south.  The Atacama, considered to be the driest desert in the world, stretches a 1,000km north and south abutting the western flank of the Andes, in its rain shadow, a result of the predominant east to west winds at these latitudes.  In Chile, these landscapes are called mattoral and are very similar to California’s chaparral and share their ‘mediterranean’ climate.  This Puya is most likely to be found on north facing hillsides, between 1,000′ and 3,200′.  Some of these large Puya species are considered protocarnivourous, entangling animals that are thought to ‘feed’ the soil and then the plants, as they decompose.  I can almost imagine their terror at becoming entangled with each struggling move only worsening their plight!  This is another acquisition for me from Annie’s Annuals, I couldn’t resist her description…we shall see how long I can keep it!  It forms a rosette 5’ tall with truly formidable foliage as you might have already guessed.  The flowers though are the aesthetic ‘hook’ forming on 12’ stalks and blooming for a few months beginning in Spring.  It takes 10-15 years to bloom, sometimes as long as 20, but than blooms every year after…one of the few Puya that are not monocarpic.

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My Puya chilensis, small and mean at this stage. If my tape measure looks upside down, recall that this is a southern hemisphere plant.

My P. chilensis is confined to a pot, which, because of its ultimate mature size will in all probability keep me from growing it into its flowering maturity…yet I have it!  It will be big and heavy, two characteristics that will cause its lifting and handling ‘delicately, to be difficult, and, consequently, a more ‘bloody’ affair.  This plant has to be a ‘9’ on the ferocity scale, it gains in fierceness, with increased stature.  As terrestrials, Puya depend on their roots to take up moisture so unlike their epiphytic cousins and true succulents these will demand relatively large soil volumes/pots to grow into healthy specimen.  Additionally, confined in too small of a pot many terrestrial Bromeliads are difficult to water, simply getting a hose or the spout of a watering can to where they can reach surface potting soil, can be difficult due to how the stiff downward arcing foliage can shed much of water out and away.

Each of the around 200 species, have their own particular range and preferences.  Puya raiimondii, Queen of the Andes, is restricted to the arid high Andes of Peru and Bolivia, where it can be found in the Altiplano, an arid high elevation plateau, averaging over 12,000′, lying between two ranges where the Andes are at their widest.  The ‘high plain’ stretches south from central Peru across Bolivia, where Lake Titicaca is located near their shared border, all of the way down to northern Argentina and Chile, the bulk of it in Bolivia. It is bound to the east by the Amazon Basin across more mountains and the Atacama Desert to its southwest.  Active volcanos abound in the surrounding mountains.  It is a huge basin out of which no rivers flow.  The plateau averages less than 8″ of rain a year which it receives mostly in the summer months.  The rest of the year is cool, dry, windy and sunny…desiccating conditions.  Keep this in mind.  You should consider this pattern for any of the Puya as most are from the western Andes growing under similar conditions.

Puya_raimondii_hábito

Puya raimondii growing in situ on the Altiplano in Peru. credit to Pepe Rocque, Wikipedia

P. raiimondii, is found primarily, in the ‘warmer’ northern portion into Peru, including Huascarán National Park which covers over 1,300 sq.mi. It typically does not freeze where it grows, this is a ‘tropical’ area despite its elevation.  It would then prefer to neither freeze nor bake.  It is the largest and tallest of the genus and family, its vegetative rosette base reaching nearly 10’ tall, its inflorescence to 23’+ even up to 29′, carrying as many as 20,000 flowers, producing upwards of a million seeds. This species can take up to 40 years to bloom and, being monocarpic, like most Bromeliads, then dies.  This particular species is considered endangered.  It is unlikely that you will find one to grow on.

Obviously then, all of the other species are smaller.  Puya mirabilis, its rosette only 10”-12” tall, which I grow in a pot, is reportedly the quickest to bloom… mine has begun after having purchased it in a 4” pot in Oct. ’15.  This plant appears more ‘lush’ somewhat softer and greener than its cousins above.  The flowers are yet to emerge, so going by Annie’s Annuals description they are,  “elegant, flaring, lime green bells held in fuzzy purple-grey calyxes”.  Like all monocots their flowers are three petaled, though these are much larger and more prominent than others that I’ve seen and will be quite prominently displayed on 3’ stems.  This too is a Bolivian species and is very drought tolerant, deer resistant and loved by hummingbirds when in bloom.  Hardy down to 20ºF, mine will be forever in a pot which suits its stature well.  Of all of the Puya I’ve grown and/or researched, this might be the ‘best’ one to grow for the mild temperate gardener: relatively quick to flower, pretty flowers, a very manageable plant for a pot, drought tolerant/mediterranean and perhaps the ‘kindest’, least aggressive foliage of the genus, I’ll give it a 2 on the scale.

Puya venusta…this is a sad story.  I bought this one from Sean Hogan that he’d identified as the ‘pink stemmed form’ on the label.  This is a beautiful, almost white leaved plant, with stiffly arcing, channeled leaves with the typical recurved hooks you would expect running continuously along their margins…but they are in scale with the plant’s stature, of up to 40” tall the offsetting rosettes can spread to 5′ across.  The flowers rise up about 3′ above the rosette.  Native to arid mountainous areas of central Chile and Argentina were it grows on sites typically with a northerly aspect, generally out of full direct sun.  It tends to inhabit areas that don’t freeze though it is thought to be safe into zn 9.  Some growers, like Ian Barclay of Desert Northwest, write that they expect this to be hardy down into the low 20’sF.  Annie’s says that it should be tough down to 20ºF.  Some rate it as a zn9 plant.  This selection was collected west of Tafi del Valle, in Argentina at 11,800’, Sean is generally very good with his collection data and this emboldened me…not always a good thing.  After growing it for a few years in a pot that I would protect from freezing weather by shuttling it down to my lighted basement, I decided to try it outdoors, in the ground.  I planted it in my south facing parking strip at the base of an established Trachycarpus fortuneii, 12’ or better tall, my thinking going somewhere along the lines that the tree would protect it from radiant heat loss and shed some of our winter precipitation away.  It did this.  The tree’s roots also helped keep the winter soil drier as well.  This seemed to work well for its first two winters, both of them mild, but it was a mistake.  This last winter was much wetter than is normal for us (See the comments under the chart above).  Combine that with the two severe, for us, cold snaps, one in early December and one a month later, and the latter dropping to about 15ºF and tormenting us and our gardens with freezing and near freezing temperatures in early December and then again throughout much of January … this plant perished.

My other Puya, P. dyckioides, another Andean Puya from Bolivia and NW Argentinia, has been successful for me outdoors. It’s been growing on my south facing retaining wall, protected by an overhanging Oleander.  It has formed a substantial clump, newer offsets crowding out older, blooming consistently over the last several years. It is relatively easy to work in and around as the leaves are neither overly stiff nor are they heavily ‘armed’.  You still should be careful and deliberate around it, but the risk of injury on a scale from vicious and unavoidable, as a 10, down to ‘you have to try to inflict injury upon yourself’ as a 1, I’d put in the 2-3 range. The plant has an overall softer, ‘grass like’, appearance.  The marginal spines are tiny.  Still, while grooming it earlier this summer, reaching in and pulling away the older dead rosettes, my unprotected forearms received many tiny and irritating little jabs, that brought up no blood, but left my arm looking as if it were covered with tiny ‘hives’ and itchy.  These take 6-7 years to reach blooming size and I believe this is my fourth summer with bloom.  If your sun is too intense, as my site would be for this plant, offer it some shade.

I am tempted to try P. venusta again and am intrigued by P. berteroniana as well as P. alpestris, they aren’t too huge, can take some minor freezing so I won’t need dedicated full time indoor space for them all winter, so for the most part they can stay out on the covered porch dry.  These three feature gorgeous, colorful and spiky inflorescences….and yes, those aggressive recurved marginal spines as well.

The Fascicularia and Ochagavia Question

Fascicularia_bicolor_(hozdiamant)_001

The inflorescence of Fascicularia bicolor with its blue flowers. The center of the foliage on a blooming rosette, turns red when the flowers appear and then, like many Bromeliad, that rosette dies replaced be previously formed offsets. My plant has yet to bloom so this photo comes from Wikipedia.

If you’re not into blood and guts, consider this genus, as on my scale of one to ten as described above with ten warning of near complete evisceration if one is fool hardy or reckless, this one’s a solid 4, or maybe a 5, dangerous enough but not stupidly so.  Fascicularia pitcairniifolia.  You would think that in a genus composed of one or two species things would be pretty well settled taxonomically, guess again. Originally described as F. bicolor it was reclassified as F. pitcairnifolia and later changed back to F. bicolor.  Subspecies were proposed.  Changes retracted.  There are significant differences in the sampled populations, but are they sufficient to constitute separate species??? Adding confusion at a different level are those who say the species name indicates that it is from Pitcairn Island.  It is not.  The specific epithet simply recognizes a similarity to the foliage in genus, Pitcairnia, another Bromeliad member.  This Fascicularia is from the Chilean Andes, allegedly north of the other Fascicuaria species, F. bicolor which is suppose to be slightly hardier and occurs at least occasionally as an epiphyte!  F. pitcairnifolia.  Some botanists have argued it possesses thicker, slightly wider leaves. and some minor differences in the timing of flowering and is reputedly slightly less hardy.  The ranges of both overlap  Good luck sorting this out.

They say that there is no shame in trying, that the shame is in avoiding the challenge…don’t they say this?  Well, I bought this one from Sean, in 2012.  Grew it in a pot for awhile and then planted it out in ‘13 on my east facing retaining wall, a rotting old RxR tie affair.  My plant failed to grow the following spring. [trans. it died.] It’s demise is recorded in my database, winter of ’14.  What happened to it?

That winter our temperatures dropped five times down into freezing temperatures, each time for several days in row.  Over two of those periods, one in early December the airport dropped to 12º and another in early February, when we dropped down to about 20º.  At the same time we recorded sub-freezing highs with our usual pattern of at least several days above normal high temperatures in-between, before freezing, even lightly again.  In other words, the typical yo-yoing that we get that can reck havoc with a plant’s dormancy making them more subject to damage or death.  The rain year measured from Oct. 1 to Sept. 30 was 5” below normal.  So, what killed it? Some growers in England say that with excellent drainage, these can go as low as 14ºF.  Well, mine was planted in the local loam right next to the wall, but it was likely still too wet.  Wet or cold?  They tend to compound the negative effects of each other.  I won’t be trying that again without a backup plant in a pot and I won’t try it unless I’m planting into scree or a well constructed crevice bed.

Fascicularia bicolor ssp. caniculata ‘Spinners’.  An interesting story.  I bought one of these from Sean after the above plant died in June of ’14.  It’s still in a pot, where I intend to keep it, though I have up potted it.  I plant it in my typical mix with added pumice making it nearly half pumice.  Once every couple weeks I set it in a tray to bottom water it along with a ‘squirt’ to the top.  Sometimes I’ll give it an additional squirt between these more thorough soakings.  This is the schedule I follow with many of my potted succulents, though I avoid the top watering of those that the practice encourages fungal growth on.  Watch and learn.  This seems to work well for my more ‘arid’ terrestrial Bromeliads.

Fascicularia bicolor grows primarily in scree, but can be found as an epiphyte in Chile south of Santiago in the Lake District.  The climate here is maritime and wet, extending well easterly into the mountains.  So this is not a desert plant.  It can often be found in trees or on cliff faces where water doesn’t sit on it.  It is relatively humid in this area.  Some growers have recommended keeping it out of direct or intense sun.  I tend to move my pots around and none of these ever get full sun though they can get a couple hours of mid-afternoon sun.  With free draining or scree I might be tempted to grow this in the ground  Overhead protection, canopy, could be of help as well.

Ochagavia_carnea_3

Ochagavia carnea, while the structure of this and the Fascicularia are very similar, even I can tell this inflorescence from the other….

I helped a friend divide another Bromeliad, I was told Ochagavia carnea, she had on ‘loan’ so three of us could each have a healthy sized piece.  She hadn’t done any of the Bromeliads before, I think also that she wanted to avoid any confrontations with the spiny margins.  So I did it, happy to then have a plant of my own.  Later I was told, by a knowledgeable third party, that this was in fact another form of Fascicularia bicolor!!!  Apparently there is quite a range in the width of the leaf blades.  Or, is this what they were talking about above with F. pitcairnifolia having wider blades than…only the two are actually one species???  Wait a minute! There is definitely some contention here.  The only thing left to do is to grow them both out to blooming and then make a determination!!!  Okay!  The Fascicularia bicolor and Ochagavia carnea have significantly different flowers so that even I should be able to tell them apart!  Time to move on!

Dyckia

Not P. dyckioides as already discussed, but Dyckia, the genus that some botanist saw as similar to that earlier Puya!  I sure don’t see it!!!  The Dyckia that I’m familiar with are all much more formidable than my tough adaptable wall resident.  My Dyckia ‘Red Devil’ is at least a 7 or 8 on the scale!  Be forewarned!  If it were larger in stature…I would rate it higher.

My only Dyckia is D. ‘Red Devil’, another plant that I got from Sean, this time in ’11.  It seems so much longer ago than that.  He ‘thinks’ its a hybrid between D. platyphylla and D. leptostachya…he thinks? Wiki lists 158 species, so yes, I suppose so, given that, what else could the parentage possibly be? Oh, wait, this person says that it’s a cultivar of D. platyphylla a species restricted to the state of Bahai in eastern Brazil.  Okay, why not?

It seems a little presumptuous to write anything here at all.  Why don’t you just go to Yuccado’s site!  Seriously, go to their site and read it!!!  It will at minimum make you a better person!  If you read nothing else there at least read the section on watering Dyckia.  The most commonly offered Dyckia are not desert plants! Most of them come from areas under the influence of the Atlantic ocean and receive their rain in summer!  Their winters are drier but the maritime influence keeps them from drying out in winter as well.  That doesn’t mean that you should water them here in cool/cold wet winters.  I leave mine outside for most of the winter, under the roof overhang and shuttle them inside my cool basement for those days of sustained freezes and cold ‘spikes’.  They will be more cold hardy if kept on the dry side for the winter, like the rest of the terrestrial Bromeliads I’ve written of here.  Do water them regularly in summer, but let the pots dry in between!  They ‘want’ excellent drainage.

11

Typical Dyckia landscape away from the ocean on the high dry plateau country of south Brazil. from the Dyckia Brazil blog site.

Other species of Dyckia come from arid regions of Bolivia and Argentina, a lot of them, with a monsoonal, summer rainfall, climate.  These get little rain and their winters are very dry.  Many species can be found in this region, but few are available in the trade.  Check out this site, Dyckia Brazil, a blog dedicated to these dangerous beauties from this region, for a lot of beautiful pics and great info compiled and posted by a very knowledgable aficionado.

Know where your plants come from and treat them accordingly.  Any  plant’s aesthetic value and health requires that you address its preferred/necessary growing conditions.  If these plants grow too lushly the leaves will not take on the characteristic color that we are looking for.  These plants, like Hechtia species as well, need to incur a certain amount of drought stress to look their ‘best’.  Of course too much drought stress, especially during their summer growing season, is not good.  Also remember  that at about the same time you get comfortable and assume something about a plant, lump it in with others that you’ve grown, you’ll learn about its differences, in perhaps a hard way, and loose the plant.  Learn about your plants.  Learn about your site.

Hechtia

My Hechtia collection consists of one cultivar of Hechtia texensis, ‘Texas Red’.  I give this selection a solid ‘8’ on the ferocity scale.  This plant ‘wants’ to hurt you!  The genus lies within the sub-family, Hechtiodeae.  Set side by side with my above Dyckia ‘Red Devil’, you would think them very closely related, maybe even from the same genus.  Physically they appear very similar.  Both plants once resided in the same sub-family, but Hechtia has been split away, for genetic reasons.  All Hechtia are native to Central America, Mexico and southern Texas and into the Chihuahuan Desert of Arizona.  Dyckia are all South American. Hechtia were isolated from the more southern species of Bromeliad as the two continents moved further apart and the Venezuelan Highlands were thrust up.  Once this happened there was no more ‘sharing of genetic material.  The process of adaptive radiation had begun.  This reclassification was not a simple geographical observation…it was genetic.  67 different Hechtia species developed from unique basal members.  Convergent evolution.  Different genetic lineages, responding to similar environmental conditions resulting in genetically different plants with similar appearance or morphology.  Hechtia developed and moved north.  Dyckia developed independently and moved south, east and west.

Hechtia texensis is native to the southern Texas, the Big Bend area around the Pecos River and NE Mexico, hardy down through zn 8 and extremely heat tolerant, growing to 8” high and 18” across.  All Hechtia spp. are terrestrial, monocarpic, once flowering plants, that readily form offsets to replace those that flower, forming a crowded clump of rosettes.  Dyckia  are not monocarpic, each rosette will continue blooming over subsequent years for awhile.  One of the keys for distinguishing Hechtia flowers from Dyckia is that the former are almost always white while Dyckia are typically brighter oranges and yellows.  Hechtia also form imperfect single sex flowers, on all but one species, each plant being either male or female (the exception has both single sex flowers on each plant), while Dyckia form perfect flowers (both sexes in each flower), are quite promiscuous and don’t require another plant for pollination.  Both have tiny scales, peltate trichomes, that grow above their leaf epidermis, like those described above, that absorb water in lieu of functional, absorbent roots, only these function to help shield these plants from damage by the intense desert/low latitude sun.  The foliage of H. texensis can turn bright red at maturity while the spiny margins remain white.  It is also important to keep the conditions of where these originated as well. Hechtia texensis and other species of more arid origin unlike those that come from wetter regions, especially of southern Mexico and Central America, are less tolerant of over watering and may respond poorly to repeated overhead watering, another reason I generally bottom water these.  You can’t go wrong doing that.

Bilbergia

I’m going to give this plant a ‘2’ rating on the ferocity scale.  There are only scattered smaller prickles on the leaf margins, which I suppose can poke your more sensitive areas, but you’d have to work at it to actually get a bonafide injury from this plant.  Bilbergia nutans ‘Variegata’ is the only one of these I’ve ever tried indoors or out…there are 63 other species.  Sometimes called Queen’s Tears, the flowers can ‘drip’ nectar and can be regularly visited by hummingbirds.  It’s an epiphyte and is native to parts of Brazil, Paraguay, Uruguay and Argentina.  As epiphytes their roots are minimal and serve only to anchor the plant, there is little reason to bother with fertilizing your potting soil, though they can be planted in the ground.  I haven’t tried them this way, but they can be mounted on wood and hung in trees.  Just make sure that they face up so that they can capture and hold water.  I grow them in both pots and in the ground.  If grown in a pot the don’t need much soil volume.  There is no need to keep their root zone evenly moist.  The only time I’m concerned with this is after I’ve divided them, pinning them in place with small bamboo stakes to stabilize the top growth, so that their roots can grow out and get a hold in the new pot.  I like ceramic pots for these, as they provide a heavier base to keep the whole thing from toppling over inadvertently.

This is an attractive plant, especially the variegated form with cream colored margins, sometimes with a hint of pink.  These have an upright structure like most Bromeliads, up to 2’ tall and can get congested if left alone in a larger diameter pot.  (Like other epiphytes there is no reason to grow them in a deep pot.) The flowers are elegant, though somewhat short-lived by Bromeliad standards, as many other genera can have inflorescences which can put on a show for weeks and sometimes even months.  Bilbergia have flowers that hang from gently arcing stems, for me generally in spring on those plants I winter indoors.  i don’t always get flowers on those I leave out, I suspect because the plants sustain some damage.

This is another plant I got years ago from Sean.  I’ve always divided them every other year so that I have what I want.  I usually plant several out and they don’t always make it through our winters, they all failed this last winter.  I learned to plant them in sheltered places such as beneath one of my larger Trachycarpus and they do better there over the winter protected from excessive moisture and radiant heat loss on cold clear nights.  Even doing this, sometimes I lose them.  Backups in the basement.

As epiphytes these should be watered from over head to fill the cups.  Our summers are dry and our humidity on the low side, usually under 40% during the day, so don’t forget about any of these outside over summer.  Let the soil around them dry out periodically.  Their roots need to breathe.

Occasionally give them a weak solution of liquid fertilizer.  Remember that all epiphytic Bromeliads gain their nutrients through their leaves, all of that decomposing organic matter they tend to collect, their invertebrate helpers break down for them.  The drip and runoff across rocks, down branches, can dissolve and carry minerals and bits of tiny organic matter and acids to them.  They need a boost here especially if you are providing ‘clean’ culture for your own aesthetic reasons.  Yes, rot is messy, but it’s also necessary.  If it helps, think of them as patients in your care with an IV drip while you nurse them back into good health!

Also, keep these out of hot, direct, afternoon sun, they prefer the dappled light provided by their overhead canopy.  Intense sun can burn these!  This is generally good advice for all epiphytic Bromeliads.  Cliff dwelling lithophytes may normally reside on north faces out of reach of the sun’s direct rays.  I know from experience.

Neoregelia and Aechmea

Most people, when they first think of Bromeliads, have an image of the large tropical and sub-tropical plants with prominent ‘cups’ created by their impounding leaves.  These include many of the Neoregelia and Aechmea and are plants that will require more serious winter protection in our temperate climate.  Mine have all been ‘gifts’ and I don’t even have cultivar names.  Obviously, there’s nothing ‘hardier’ about these.  These are tropicals and when it starts dropping below 50ºF outside I bring them in and put them under lights.  Cultivars are often selected for their vibrantly colored and patterned leaves which compliment their architecture.  Just a few in prominent locations make quite a statement.  Keep in mind the need to place these in bright, but not intense sunlight.  This will allow the desirable colors to develop without causing the plants to ‘burn’ as has happened to one recent acquisition that could best be described as pale yellow-green and almost white.  Chlorophyll, the magical green pigment that it is, also serves to protect many plants from the damaging rays of the sun, so when plants with little of it are exposed to intense sun, they are often subject to ‘burn’.

Along with the shared physical structure of these plants, their is a similarity in their ‘substance’.  Like many of their other family members across the many genera, the leaves of these possess a similar substance, toughness and rigidity.  A certain characteristic ‘hardness’.  This does a couple of things for these plants.  First, those spines and prickles that you see on the leaf margins? it adds to their ability to ‘bite’, holding each one more rigidly.  The ‘spines’ on this group are small and separated and, if not for the rigidity of the leaves themselves, wouldn’t present much of a hazard to the gardener, but on these plants, I’d rate them as a 3-4.  Just reach in with an ungloved hand to find out.  While they may not draw blood readily they will leave a trail of pin-pricks across the back of your hand.  Their rigidity is increased by the ‘in-rolling’ and overlapping of the impounding leaves.  To understand take a piece of paper and roll it up…see!  Rigid!  I once saw a man in a movie kill another character with a tightly rolled magazine…so, it must be real.  Or was that Uma Thurman in ‘Kill Bill’?

Propagation by Division

A few words on dividing your Bromeliads…. Bromeliads form offsets.  They are not like most woody plants that grow in caliper producing an ever larger individual plant.  They don’t form bulbs or bulb like structures, corms, tubers, wiry or thick rhizomes.  They don’t spread by stolon.  Nor are they like most herbaceous perennials that can form a very congested crown that can be teased apart during dormancy into separate plants or simply cleaved up in half or quarters.  One doesn’t take cuttings either to stick into a jar of water or dust with rooting hormone and stick in media.  Bromeliads are all treated very similarly to each other.

These are Monocots. and with relatively few exceptions all of the growth originates from the meristematic tissue at the plant’s base.  This is where all cell division, whether it is for roots or top-growth, initiates.  Each Bromeliad will do this in their own way, at their own rate.  An offset initiates from the same meristem tissue laterally from the ‘mother’ plant’s base.  From this, top and roots form, creating a separate, defined plant.  This is cut away in its entirety.  Not further divided.

Most of my experience dividing Bromeliads is with Neoregelia, Aechmae, Bilbergia and Dyckia.  The main differences are how they vary in how congested the offsets form and, of course, in each species ‘ferocity’.  Once safely out of its pot, which can be a chore, plant these all in pots that flare out, getting wider as you move to the top.  Their stiff, downward arcing and armored leaves can make it impossible to move them out of the way.  Often times when ‘depotting’ a plant I slide a stiff blade down around the insides of the pot to help release the root’s ‘grip’.  This won’t always be possible with Bromeliads.  Plan accordingly.  This also makes separating the offsets from one another…interesting.  There won’t be any ‘teasing’ apart.

Division should be down while the plants are in active growth and temperatures are adequate to support it.  It will do them little good to be merely stored in the cold after dividing.  Each offset is solidly connected to its ‘mother’ plant and will need to be cut cleanly away from it.  This is easily down with the epiphytes as your potting mix will almost fall away on its own from the few and short anchoring roots.  On the terrestrial species, these is considerably more challenging.  If left for too long in its pot the resultant root growth can get quite dense.  You will need to work into the ‘crown’ of top growth from the bottom, while being ‘careful’ not to smash and damage the stiff top growth while you work on it.  Eventually you will work your way into it.  When you cut them apart be sure to include enough of the base, this is, again, where the meristem tissue is, so that it can grow in a healthy way.  Your offsets, even the terrestrial ones, may end up with few roots on them.  This is okay.  Lay your offsets aside for a couple of days in the cool shade where the cut surfaces can dry some and begin to callous.  Then with appropriately sized pots, depending, again on whether it is terrestrial or not, how big the plant will grow and how frequently you plan to divide it, (Old congested plants will be more difficult to divide.) repot them in a well drained mix, somewhat heavier for the terrestrials.  Don’t bury these too deep in order to keep them upright as this could cause them to rot.  Only the base should be in the soil.  Stabilize your plant buy surrounding it with at least 3 skinny bamboo stakes, set aside, in bright indirect light and water it in.  Don’t keep the soil constantly moist.  The roots will need to ‘breathe’, so light it get dry to the touch.  Minimize moving them around as the offsets will be liable to topple were quite awhile.

Watering and Water

I often see it recommended in print that when watering epiphytic Bromeliads that one use distilled water.  I don’t.  I use it straight out of the tap, of course Portland water is very ‘soft’ having very little mineral content as is common in many cities and regions.  When running glassware through a dishwasher cycle here we get very little to no ‘spotting’ even without using the water ‘softening’ additive.  My Bromeliads, likewise don’t suffer from any spotting.  There is no mineral buildup.  In their native landscapes epiphytes are the recipients of rain and condensate, directly.  Rainwater is free of minerals.  Keep in mind that water is ‘purified’ through the process of evaporation.  Particulate and acids are picked up after the vapor condenses on a nuclei in the atmosphere which can include dust, particulate and several pollutants.  Some pollutants can even acidify the rain.  Nowadays the many pollutants we have released into the atmosphere can effect the chemistry of our rain.  The largest sources of minerals in tap water come with soil contact as the water moves through the soil as groundwater, down rivers or old corroded pipes.  So, I don’t worry.

Arid terrestrials and epiphytic plants of wet jungles and cloud forests share much within the Bromeliad family in spite of these seemingly radically different growing environments.  I discussed only briefly early on how this family is dominated by species that follow the CAM photosynthetic pathway.  Most plants around the world that take this pathway, are desert plants that cannot afford to be inefficient in their use of water.  A lot of these are also succulent having the  ability to store excess water within their tissues, something that none of the Bromeliads do, but they are scrupulous with their use of water.  Within the family the arid group of plants take advantage of this pathway to live with water in very short supply.  In the other group these plants take to the trees and rocks to limit the amount of water that they must deal with at anyone time high up in trees or on cliffs, relying on condensation or the limited drip beneath a tree canopy.  There they can gather what they need and hold it to themselves, while their roots merely hang on.  All of these plants then live under ‘reduced’ water conditions.  Remember that Brazilian Dyckia that clings to rocks next to a stream that periodically inundates it?  These use very similar adaptations to limit excess water that others use to gather and hold it.  The CAM pathway allows them to set the ‘bar’ at a manageable level and occupy niches that would otherwise go unoccupied.  To paraphrase the line from the old Art Linkletter Show, ‘Plants do the darnedest things!”

My Bromeliaceae genera: under previous 3 sub-family classification based on morphological studies/ and the 8 sub-family scheme proposed by some researchers based on their genetic studies.

Aechmea cv./ Bromelioideae/ Bromelioideae

Bilbergia nutans/ Bromelioideae/ Bromelioideae

Dyckia ‘Red Devil’/ Pitcarinioideae/ Pitcarinioideae

Fascicularia spp./ Bromelioideae/ Bromelioideae

Hechtia texensis/ Pitcarinioideae/ Hechtioideae

Neoregelia cv./ Bromelioideae/ Bromelioideae

Ochagavia carnea/ Bromelioideae/ Bromelioideae

Puya spp./ Pitarinioideae/ Puyoideae

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