Flowering…A Reason of Their Own:  A Look at Agave Flowers, Structure and Relationships

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This is one of the lower umbels, the second peduncle from the bottom. The others contain more individual flowers. This umbel was caught in the stage where the filaments are collapsing and the styles extending. Nectar has spilled to many surfaces. The tepals have begun to shrivel as well. Coarse pollen grains show on the anthers with some ‘spilled’ to other surfaces. Individual flowers aren’t particularly pretty.

Flowers can be ‘incidentally’ beautiful.  We often selfishly view them as products of nature intended to fulfill our own hunger for beauty, failing to recognize them for what they are, living organic structures evolved over time to continue their own species, organs and tissues meant to attract the necessary attentions of pollinators, to produce the seed of generations to follow. We, as a society, have learned to view a select few of these as beautiful.  We respond to them in a way not unlike the pollinators themselves do, and by either ignoring them or focusing our attention upon them, we too alter their future form and their very existence.  Sometimes we do this more directly through choosing the plants we want around us.  Other times it is our indifference that seals the fate of a plant or landscape, especially when the flora is unable to grab our often preoccupied attention and we clear land for development wasting all of the ‘lesser’ weedy natives we’ve learned to undervalue, or, through our efforts to ‘improve’ plants by controlled breeding and hybridization, intentionally altering their form even the conditions under which they will grow.  Sometimes, in our desire, for fashion and an idealized beauty, we attempt to control and remove that which we don’t want, creating sterile flowers, the antithesis of what a plant would ‘want’.  We select for bloom size, scent and color, for period of bloom, we seek to increase the number of petals and alter the pattern they may be held in, even the lifespan of the individual flower, the height of the plant so that it doesn’t flop over, the ability to grow it in more sun or shade, the shape and color of leaves and the form of the whole plant.  We attempt to control all of this and crank out a uniform product that can be ‘plugged’ into landscapes and gardens as desired.  Plants with dependable performance characteristics, a pedigree.

We need to remember that this is what we ‘want’, not what the plants ‘want’, nor is it necessarily in their best interest as either a species or a member of a plant community.  These days most of ‘us’ aren’t gardeners.  Our relationships with nature were broken long ago.  It is difficult to see the critical connections in nature, between plants and the organisms they have evolved with, upon which they are dependent, especially if someone is not looking.  It is even more difficult to see where we ourselves fit into this in our materialistic, consumer society where so many of us measure ourselves and others by the things and property we own…and are quick to ‘take’ from others.  I’m going to paraphrase a snarky rejoinder I’ve heard these last several years, ‘Yeah, you’re special, just like everything else!’ and I mean this in the broadest sense.

Flowers are ephemeral not fixed elements for our gardens.  For me, much of their beauty comes from this, these little miracles of nature, that are all around us if we look, passing so quickly and not always elegantly, through their brief lives.  Not all flowers are ‘beautiful’, many are in fact nondescript or inconspicuous as individuals lost amongst the millions of others across a field of wheat or an alpine meadow, or hidden deep near the leaf axils of a dense evergreen shrub…yet, flowers they still are.  Others possess characteristics, such as scent, that are in fact, repulsive to us.  We have to remember that flowers are not here for us.  They serve another essential purpose and our selection or rejection of them as desirable garden subjects is an entirely selfish one.

Flowers are the sexual organs of the plants that produced them, they are in a sense plant ‘genitalia’ and contain in their ovaries the place and conditions supportive of the formation of fruit and seeds.  Botanists are very good at looking at these processes and relationships and seeing them for what they are…the rest of us though….We don’t like to talk about sex.  “Not around the children, dear!”  So it is easy for many of us to see flowers as things of beauty intended for our visual pleasure ignoring their purpose…seeing them strictly as ornaments.  We want what we want or we want more.  And we can be terribly disappointed when we don’t get it, almost as if we have been wronged and tear out the offending plant that failed to measure up.  Plants have their own agenda.  Survival.  Over the span of millions of years they have evolved very specific structures and relationships that have proven to best serve them.  They work at these continuously as the many players and forces in play change and evolve themselves.  In more recent times we have disrupted relationships that may have existed for for many thousands or even millions of years within their natural communities.

Flowers and the Power of Their Pollinators

One of the most powerful forces in the evolution of plants and their flowers has been the arrival, proliferation and dominance of today’s many pollinators.  For many plants these are essential for their survival and evolution.  While many have evolved more generalized relationships more than a few are very specific where if either the plant or pollinator species declines or disappears the other will follow dying out completely or, perhaps, continuing on in another portion of their ranges where both still exist in needed numbers.  Most land plants are fixed in place from the moment of their germination.  However long or short that may be, they will remain rooted there until the end…a season or two or a thousand years or two.  Plants, like other organisms, depend on the mixing of chromosomes.

Many of the earliest plants relied on wind for pollination, producing relatively enormous quantities of pollen, as much would fall off target.  Many of us suffer allergies when these plants, like grasses and conifers, let loose their pollen. The more successful of these wind pollinated plants, those still with us today, occur in communities with relatively high populations and densities.  Their’s is a strategy of numbers, the higher, the more likely that non-targeted wind pollination will be successful, the fewer the plants or the more widespread, the less likely they will be pollinated.  Flying pollinators, especially, those that target plants with similar characteristics, will be able to bridge wider gaps between plants of the same species.

Some plants pursued a strategy that did not require the pollen from other plants, they could be ‘selfed’, if need be, to continue the next generation, a strategy that would be less than ideal over the long term without the regular ‘mixing’ of chromosomes, but would continue the ‘line’ should conditions not be supportive.  Some of these plants had ‘perfect’ flowers containing both male and female parts in one flower and would release their pollen when the female stigma was ‘ready’.  Others, with perfect flowers, might release their pollen before or after the stigma was ready and depend on pollen from other flowers, from elsewhere on the plant or from another.  Others still carried male and female flowers sometimes on the same plant while individuals of other species carry only male or female flowers.  None of these are ‘better’ than the other, they are merely different and are the evolving ‘result’ of ‘decisions’, of mixings of chromosomes, over the coarse of thousands of generations.  Each flower contains a story, a history, of that plant and species.

The pollinator relationship evolved over time.  It did not emerge full blown with the many species playing greater and lesser roles.  Magnolias, among the oldest plants to have evolved this relationship, many of which remain with us today, were pollinated by beetles climbing up the central flower structure, collecting pollen from the flower’s anthers while crawling around.   More modern plants, still having arrived on the scene millions of years ago, have found success relying on other organisms to pollinate them, many of them flying, increasing the odds that more scattered plants will be successful.  Some require cross pollination.  Some don’t, but may be more productive if they are cross pollinated.  This regular mixing of genes gives these plants an evolutionary advantage over long periods of time.  Plants and pollinators have evolved their relationships and their forms in concert over nearly countless generations.  This more complex flower/pollinator relationship has been very ‘successful’ when judged by the number of species alive today.  as they have greatly increased relative to the others.  There is nothing haphazard about this process.

Flowers themselves vary widely in their structure and longevity.  Some, like many members of the Orchid family, are relatively durable and remain on the plant for long periods (I do not know if they also remain viable and active as seed producers over this period.  Individual flowers possess an ovary with limited ability to produce seed so once pollinated are functionally done.)  Other plants may seem to carry their individual flowers for several months, when in fact, plants like Hellebores, their flowers having gone through their cycles producing their seed, ‘deceive’ us, their more durable and colorful bracts, remaining in place of the faded petals and flowers themselves, looking to the uninitiated, like the ‘petals’ of the flowers.  They are not.  Many other species have flowers that remain intact for only a few hours before their various parts begin to wilt and fall apart while the ovaries remain and get on with the business of producing seed, or having missed the opportunity because of weather conditions and/ or the absence of pollinators, begin readying the next in a series of flowers.  Some plants have adopted a strategy of ‘serial’ blooming opening a series of blossoms one after the other, often blooming long after the first have come and gone.  Others may open and then close during mid-day limiting their moisture loss during the heat of the day when their pollinator is not as frequently about.  Others may close at night reopening in the morning while others do the opposite.  Flowers are unique in structure and, often, in ‘habit’.

Sharkey’s World of Flowers

In an earlier posting I discussed the flowering process in general in genus Agave.  Here I’m going to look more closely at the individual flowers themselves as a way to look at flowers across the many species that populate our world and gardens.  In early July when  I began to write this ‘Sharkey’s’ first blooms had finally opened.  The flowering process on my Agave x ‘Sharkskin’, Sharkey, is a long one, first coming to my notice this spring on April 7.  In the world of flowers this is a very long period and required a prodigious amount of the plant’s resources, producing a structure that has stalled at 20’ 5” tall.  In the just over 5’ tall top portion, a modified, somewhat stunted, panicle structure has formed, with stubby secondary peduncles reaching out about 2” in a regular pattern spiraling up the main stem.  Individual flower buds formed at the ends of these in a simple umbel form, crowded together.  Over time, slowly, these buds swelled in size giving the panicle a much more massive look than it initially had with the rather sparsely located peduncles.  While the buds swelled they also began to take on a yellowish color with a blush of red.

IMG_6218Each bud appears to be incised vertically dividing it into segments which eventually separate into the six tepals, that, once the process begins, reflexes back relatively quickly.  There are no petals as such, nor any bracts at the base of the corolla.  Each flower of an umbel opened on the same day, within a few hours of each other, clearing the way for the extension of the filaments and anthers.  (Like Liliaceous plants the flower’s parts are in threes, with slight modifications.  Agave were at one time grouped in the Lily family.  The three petals and three sepals are undifferentiated appearing as 6 identical tepals and rather unglamorously so.  There are 3 stamen in an Agave flower and the stigma is also divided into 3 atop the single style.  Down in the ovary are a corresponding three chambers within which the gametes, the ‘plant sperm’, fertilizes the ‘egg’ and growth of the fruit and seed commences.)  By the next day the filaments have extended to 4” above the flower’s base, long and straight, the anthers fluttering in any breeze.  The stigma and the style are well below the anthers at this time and are in fact inactive at this stage.  Nothing can ‘happen’ until later.  The pollen has not yet been released from the anthers and the stigma is not receptive.  Nor has nectar been released.  This flowering process progresses up the stem from peduncle to peduncle and umbel to umbel.

In the world of flowers pollen serves as a major protein source for many bees, but bees are not the major pollinator of many Agave flowers, they often serve a secondary role, the bees often ‘stealing’ nectar from the flowers because they are too small to come into regular contact with the anthers which are high above.  At a certain point, before the anthers split open releasing their pollen (technically termed dehiscence), the flow of nectar will begin.  The nectar itself also serves as an attractant for the ‘desired’ pollinators.  (Many different animal species have been observed on Agave flowers including: honey bees, bumble bees, carpenter bees, hummingbirds, orioles, sphinx moths, butterflies, wasps, hawk moths, bats, and a variety of small solitary bees.)  The composition of the nectar varies from species to species in accordance with the most strongly associated pollinator(s).  When you think about this it makes perfect sense, each generation of pollinators being most strongly attracted to the flowers that ‘appeal’ to them, or meet their dietary needs, making them more likely to perpetuate themselves, their young returning to the flowers that share these characteristics.  There is a comprehensive study of the pollination of two species of Agave, both branched, panicled, forms of the group Ditepalae within the genus Agave.  While relatively technical it is a fascinating and not too difficult of a read.  The two discussed Agave are, A. palmeri, traditionally grown for generations by indigenous people, the Hohokam, who grew them in southern Arizona as a winter time source of carbohydrates, and A. chrysantha, a slightly more northerly species whose natural ranges overlap.  The researchers studied these in depth in natural stands in southern Arizona.

Agave in this group, many of which are found in tropical Mexico, the center of genetic diversity for Agave, are pollinated by two species of nectar feeding native bats and the southern most portion of our own desert SW.  These Agave are, therefore, known as chiropteriphilous, or bat pollinated, plants.  The bats follow the blooms of columnar cacti north through Mexico and take a more mountainous route back feeding on Agave nectar.  The sugars in the different species that make up the Littaea group that flower on a spike or raceme with each individual flower attached to the main stem by its own pedicel, are different.  Littaea Agave are pollinated primarily by hummingbirds, bees and other insects.  Bat pollinated Agave nectar contain other sugars and some amino acids necessary for the bat’s young and, interestingly, are those consumed by indigenous peoples and still used in the production of various alcoholic beverages today.  Researchers have found supporting evidence that nectar composition, form of the inflorescence, odor and color of the flowers of Agave species in these two groups vary with their dominate pollinator.  These are not random associations.

A. chrysantha and A. palmeri are both more northerly species, lying beyond the tropical zone in Mexico where the bats are more numerous,  A. chrysantha extending even further north.   The bats are becoming less frequent in this portion of their former range.  Other northern Ditepalae species, and some of these range into Utah and beyond, have been found to be rarely or never visited by these bats.  These Agave in this group have been altering their flowers to attract the available pollinators.  These more northerly Agave, like the Littea, have a ‘sweeter’ scent that is more attractive to other pollinators and ‘brighter’ flowers as most other pollinators are diurnal and rely more on visual cues (There are Littaea Agave in tropical Mexico which are pollinated by the usual ‘sweet feeders’ such as hummingbirds, of which there are many species found locally, bees and other insects).  Nectar feeding bats are more attracted to the scent of spoiled fruit and, being nocturnal, do not respond to more brightly colored flowers.  The more northerly Agave also release their nectar in the early morning to be ready for the early visits of their diurnal visitors.  Even pollen release, the splitting open of the anthers, varied whether they were predominately bat or day time pollinated.  The differences are more striking as you move north and south into or out of the bat’s range.  Southern Arizona appears to be a transition zone at the northerly limits of the nectar feeding bats.  In this transition zone most visits to either happen clustered around either the mornings or evenings with bats on the ‘darker’ side and the diurnal visitors primarily during those non-mid-day hours for these transitional Agave.

Agave are very heavy producers of nectar.  These grow in climates that can be described as desert or semi-arid, where water is a powerful and limiting factor, they are otherwise scrupulous water users.  Depending on their pollinators again, Agave release their nectar early in the evening to attract their crepuscular visitors or early in the morning in time for the first ‘day shift’ of insects or hummers.  It is plentiful too, excessive even, which in the absence of pollinator/nectar feeders will literally spill down the flowers.  Normally, especially with crossover species like A. palmeri, that which is not fed on by the primary pollinators will be by the others, little is wasted.

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These buds have just opened this morning and the filaments are quickly stretching to their 4″ length to hold their anthers well above the still ‘waiting’ styles.

These Agave, like my own ‘Sharkey’, are protandrous, with their stamens, male parts, maturing and releasing their pollen before their pistilate, female parts, mature, taking several days to move from one phase to the other, varying with species, making it difficult for a single flower to pollinate itself.  Agave are programmed for cross pollination and are not easy to successfully ‘self’.  They also have a relatively low success rate regarding the formation of fruit and viable seed in general which is worsened when pollination falls to species that are less adapted to the Agave.  There are very real physical reasons why some species have difficulty ‘doing the deed’ as mentioned above.  Bee behavior can also work against this as well since they tend to work one inflorescence at a time and self pollination is generally less successful with these Agave. Hummingbirds may hover above the flower feeding without coming into contact with the pollen on the anthers and so may move between flowers without completing the task at hand (Apparently Littaea Agave, flowering in a raceme, hold their flowers more closely making it more likely the hummingbirds will be successful pollinators of them).  Hawkmoths, as less adept fliers, may come into contact with pollen, moving it successfully, if they are around.  Bumble bees too, being larger, ‘clumsier’ fliers have a higher likelihood of successfully pollinating an Agave.  (Here’s another study of flower adaptation to bats and hawkmoths in the same Agave spp. and in a species of Datura.)

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This shows several things: the intermediate structure of this hybrid cross of a Littaea parent with a Ditepalea Agave; how flowering progresses up the stem moving from the staminate/male period, with extended anthers to the pistilate/female period when the stamens have collapse and the styles are extended and erect and downward to the stage when the styles have collapsed and the flower begin to disintegrate. This picture was taken an even two weeks after the first flowers were opening (those first umbels were removed. One of which is pictured at the top of this posting.)

Timing

The other thing to keep in mind is that pollination of these Agave has to happen within a very narrow window.  The pollen of each flower is available for a short period of time once it is released.  Release happens in each flower of an umbel over a few hours at night or early morning, again, depending on whether it is primarily bat pollinated or not.  This must then be transported by pollinator to the mature stigma on another plant or lower down on the inflorescence, as they are protandrous, as described above and not very self compatible.  The filaments supporting the anthers collapse within a couple of days after this release as the style extends, the stigma becoming receptive, open and wet, only after it reaches full extension several days after the release of pollen.  If the weather is too cool or wet at the critical periods, impeding the movement of pollinators…no pollination.  Once pollinated the gametes ‘compete’ to grow a tube down through the style to the ovary.  This tube is necessary for the gametes to move down and fertilize the egg, one to form the germ plasm which contains the genetic information to grow the plant, the other to begin the growth of the endosperm which will nourish the growing plant upon germination.  Cool conditions can conceivably slow the process of the growth of the pollen tube.  If it is interrupted the process must begin again from another pollen grain. Time and conditions must be supportive.

Sharkey Specific

On ‘Sharkey’, the first flowers, in the lowest peduncle, opened on July 4.  The second peduncle opened by the morning of the 5th. Over these early days our weather was cool and damp with whole umbels opening on successive days. By the 8th this rate had increased with another three umbels opening while the anthers on the first umbel to open, four days earlier, were collapsing.  Durning the morning of July 9th I cut off the two lowest peduncles, their anthers and filaments collapsed in a wet sticky nectar drenched mess below the now erect and extended style.  After cutting open one of these, including its ovary, there was enough to wet the paper I was working on top of.  Nectar was running from these five day old flowers yet no where had I observed bees or any other pollinators.  While I don’t have the night vision goggles that the researchers had at their disposal, I don’t believe that there were any night time visitors here in Portland.  In the desert most daytime visits were in the morning or early evening hours.  Hummingbirds, like our resident Annas, seem completely oblivious, busying themselves with flowers throughout the garden unaware of Sharkey and the nectar literally spilling from it.  This changed.  When we returned from a few days out of town.

After our return, on the 13th, we found Sharkey swarming with bees!  This is the speculation part.  I could not get close enough to identify the bees due to the height, I could only see them backlit against the sky.  I’m going to assume that they were domestic honeybees, the size seemed consistent and right.  As generalist pollinators selected for this characteristic, domestic honey bees are adept at finding pollen/nectar sources, it makes sense to me that they would be the first of the bees to accept this oddity here in Portland and visit it.  This is consistent with instinctive behaviors across species, their ‘wiring’ is genetic and sets a base for their ability to adapt and accept new food sources.  Other pollinators that are more specific may be unable to make this adaptation.  I suspect that our many native and solitary bees will be slower to make this change.  Domestic honeybees, as a more ‘social’ species, can communicate this discovery to the others whom have never seen it.

Many of our native pollinators are solitary or live in small groups.  I was sitting reading on the front porch around 5:30 one night and looked up to watch an Anna’s Hummingbird sitting, and ‘clicking’, on an overhead wire off to the side with the bees busy below. After a minute or two, it shifted positions to the other side of the inflorescence before it looped down to it, sending a couple of anthers falling to the ground while it momentarily hovered at a flower. Did it feed? I don’t know, it wasn’t there for very long before it zipped away.  I never saw it return.  I stayed out that night until it was too dark to see movement against the sky and saw nothing after the bees left a few minutes after 9:00.  Bumblebees, Hawk and Sphinx moths, all resident here in the Willamette Valley, have to my knowledge not yet discovered this nectar source and as solitary insects may not?  In the plant world, the planting of regionally exotic flora does not mean the pollinators will come, they may if the flowers are familiar enough.

It is interesting to note here that I grow several other Agave family members which are regularly visited by solitary pollinators.  I’m thinking of Beschorneria and Hesperaloe, both of which bloom annually, and are visited by local hummingbirds and neither of which occur anywhere near the Pacific Northwest…yet they are visited regularly.  I haven’t watched them specifically for bee activity.  These plants for me produce very few fruits so the pollinators aren’t very successful though the fruits that I’ve opened have been full of seed.  The same goes for the several Bromeliad family members that I grow, at least the Dyckia, Puya and Hechtia, I’ll have to pay closer attention to my Bilbergia.  I split open a fruit on my Puya dyckioides and found developing seeds.  My point is that hummers are attracted to other exotic plants. Many honey bees are drawn to the thousands of exotic flowering plants that have found their way here intentionally or not.  How common are the visits of our native bees to exotic flowers, which ones and what’s their frequency?  Hummingbirds regularly visit the big exotic flowers of Cannas here.  This leads back to the possibility  that as a hybrid of a Littaea and a Ditapelea parent, has ‘Sharkey’ inherited characteristics that are off putting to some pollinators like hummers.  Does Sharkey’s nectar lean more toward the bat side of its family?

A hybrid, single plant in a garden many miles out of the natural range of either parent, with an intermediate inflorescence unlike either parent, each parent a member of the two different groups within genus Agave… presents a challenge  Which pollinators will be attracted and effective?  Is it giving off mixed signals?  A. scabra ranges from south Texas across Mexico south to the Pacific, while A. victorae-reginae, the other parent, is found in the Chihuahuan Desert of northern Mexico broadly overlapping with A. scabra.  Local pollinators in their home region would no doubt be more apt to visit these hybrid progeny, but do they even there?  Are the progeny of this cross in their home range sterile?  And, as a hybrid, if it does form viable seed, which parent will it most resemble?  Would its mix of genes present an unfathomable puzzle to pollinators even there?  Would the ‘gap’ be too great for effective pollinators to figure out?  If there were enough other mature flowering adults of this cross in the area would pollinators be more tempted to try?   Would it be more familiar?  In nature, individuals that occur too far beyond the norm, are likely to fail.  Pollinators care little about the physical characteristics that might appeal to the gardener.  Hybrids of whichever species run the risk of being sterile mules.  Nature moves in incremental steps.  Agave x ‘Sharkskin’ is a selection made in Saltillo, Coahuila, Mexico, by Ruth Bancroft, a ‘natural’ cross, selected for its unique ornamental characteristics as an immature plant.  As I’ve written in other postings every seed, even if it does germinate, will not be successful in its ‘journey’ towards maturation and the successful production of viable seed.  This human selection, left on its own, may have been a dead end with new progeny being occasionally added when the two different species cross again.  Nature works in a manner that can be characterized as dynamic stability and moves in incremental steps.

By July 21 I began to notice withered ovaries hanging toward the bottom of the inflorescence caught in the tangle of shrunken and twisted floral parts.  The wind blew and it was 90F.  Some were blown free and dropped to the ground.  I examined these.  Their anthers had fallen away otherwise all their parts were intact, shrunken and leathery, the ovaries on their way there.  I split a couple open and saw no sign of seed.  These were aborted by the plant, apparently unfertilized and unsuccessfully pollinated.  More were hanging toward the bottom of the inflorescence.  These could be the result of the early days when I observed no pollinators at all near the flowers, or it could be indicative of a larger problem with this hybrid and/or growing it here in Portland.  The following day brought a significant rain which helped clear the inflorescence of aborted hanging. Many of those that remained appeared to be developing seed with their swollen more rounded forms.

The bats associated with chiropterophilus Agave in southern Arizona and Mexico are less common than they once were, especially in the US portion of their range.  These Agave have become more dependent on ‘secondary’ pollinators.  Had they been unable to adapt over time, they would have simply died out, but they have and are now able to take advantage of the pollinators that are available, while retaining the branched or panicled structures of the plants that they descended from.

Agave are, across their range, losing habitat to agriculture and land development throughout much of Mexico.  This does not bode well for the Agave species that are strongly associated with these bats as pollinators…unless they can adapt quickly enough.  Both the bats and these related Agave species have evolved together in process described as mutualism.  Over time, the stronger this relationship, the more dependent they become each ‘shaping’ the other.  A species that takes many years to reach maturity and then only flowers once is less responsive to human induced changes that come more quickly.  As in many other cases in nature, those more adaptive species are likely to be left as survivors while we lose the narrow specialists.  This translates into a loss of genetic diversity which will have long term survival impacts in as yet unforeseen ways.  Those of us who may garden and grow these plants, will over time find that we may have fewer to choose from.  In some cases our demand encourages the theft of plants from their natural ranges which has lead other already precarious species to the brink of extinction.

Communities and Essential Relationships

The sustaining relationships of any given species cannot be wholly dependent upon us.  We are all familiar, to a greater or lesser degree, with the limits of our climates and the particularities of our micro-sites.  We are less aware of the necessity, ultimately, of the many relationships that plants have evolved with to ensure their long term survival.  Each of these relationships that we ‘break’ puts a heavier burden on us, to take up the ‘slack’, to fill the gaps we have created by disturbing and destroying their natural communities and planting those that we choose where we have or leaving them on their own to be colonized by, available and local, ruderal species.  Their success requires that we nurture not only the plants, but the pollinators and all of the other organisms, plant and animal, necessary to maintain the particular conditions that the plants in our landscapes and gardens are ultimately dependent upon.  We would be much further ‘ahead’ if we permanently set aside more of our natural landscapes where these relationships and communities could continue at their own pace and not the accelerated one that we impose on them.  Our actions too often are disruptive and destructive.  We, at this point, have a very limited understanding of what we are ‘breaking’ and the long term consequences of that for these communities and, ultimately, ourselves.  We commonly view ourselves as above and separate from nature when we are in fact very much a part of it.  Because we do not recognize the life giving relationships we have with this place we should be much more careful before we end them.  (E.O. Wilson has written in his recent book, Half Life, about this need for set-asides, that we are sacrificing the survival of uncounted species before we even know how many species there are let alone understand the importance and nature of their relationships, including those with us, which we depend upon.)

Understanding ‘Sharkey’, or any organism, as an individual, gives us an incomplete picture.  Years ago in my ‘Plant Materials’ classes we learned plant after plant each week, nearly 400 by the end of the school year.  Common names, botanical names, families, height, habit and width, growth rate, disease and insect problems, preferred soil, moisture and light conditions…being quizzed every week, at mid-term and final.  We created our own little herbariums with dried and pressed samples.  We visited each in they field, though they were growing in urban conditions as part of contrived or built landscapes.  But, as I learned over the years, as I’m still learning, this was a starting place.  No plant can be truly understood on its own.  Studying a plant, observing one as I’ve been doing with Sharkey, presses us to ask questions, and gradually, we begin to realize, that removed from its community of origin, any plant is incomplete.  As gardeners we continually struggle with this, whether we, in our eagerness, plant an individual in marginal conditions with unrelated others, or scrupulously work to duplicate plant communities that we have seen grown in very similar conditions…or at least they seem to be the same.  The fact is that there are so many different relationships at work in natural plant communities that it is near impossible to intentionally duplicate them…not that we shouldn’t try.  My thought, that as free to move organisms ourselves, organisms without direct physical connections to all of those that we too are dependent upon, that we possess a bias that sees other organisms, plant and animal, as individuals as well…but that is wrong.  All are interdependent members of a complex matrix.  Our independent movement, our rational brains, feed our weakness that is hubris, causing us to believe that we know, that we can separate essential from non-essential and create the conditions both necessary and supportive of the full expression of life.  We reform the landscapes we come in contact with as controlled experiments in art or as our expression of utility while we fail to recognize the millions of little miracles all around us that make life possible and are supportive of this particular moment in history.  A rose is not just a rose, an agave just an agave, they are compilations of all the relationships, historical and current, that brought them into being and daily support their existence.  Sharkey is an anomaly, not its existence, as it is a product of two species that have come into contact in their shared range, but because it was human selected, propagated as a clone and has since been distributed around the world into contrived landscapes. We pulled it out of the stream of nature and placed it in a landscape of our making, static and controlled, where it now exists outside of its community and system of support.  This is fine.  I am a gardener.  I have no trouble with gardens.  We just need to remember where plants come from and understand that their full requirements, for long term survival, are met in natural landscapes not in our gardens.  Without those natural landscapes complete with their systems of relationships, any species is doomed over the long term.

We too are the result of millions of years of evolution, of soil, climate and living organisms that have all arrived at this precise moment.  Much of the joy of gardening involves the rediscovery of these wonders that exist within the world around us, the myriad forms it takes and the amazing relationships that are shared, in this active celebration of life.  Agave flowers are works of ‘art’, functional and elegant, each unique and necessary.  Watching mine bloom has been an opportunity to delve more deeply into the very idea of a flower and how much richer they are than their simple collection of parts that we might arrange in a vase or clip off and discard should they clash with our expectations.  Flowers do not exist in a vacuum.  They are essential role players within a too often forgotten community each member of which plays a necessary part that effect all of the others…something we can learn from.

Please see my other postings covering my experiences growing Agave in the maritime Pacific Northwest and their flowering.

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