Category Archives: Flowering

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. Continue reading →

Flowering and Its Trigger in Genus Agave

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Agave parryi with both secondary and tertiary peduncles and the elongated yellow anthers 'floating' above.

Agave parryi with both secondary and tertiary peduncles and the elongated yellow anthers ‘floating’ above, in Sedona, Arizona.  From  americansouthwest.net.

 

 

As gardeners we come to know our plants, what to expect from them over time, how we can better meet their requirements,  and their contributions to the garden.  If we watch we learn when to expect their spring time resurgence, the extension of stems and unfurling of leaves.  We anticipate their flowering often recomposing vignettes to best display them.  They teach us over time.  But with Agaves their flowering is so infrequent, that if we don’t study them in mass over a span of years, we won’t know what to expect.  With some it can take as few as six years, some even less, while others will keep us waiting for 30 or more.  When we buy a year old grafted Magnolia we are told to be patient and we understand that the tree will take some time to grow and mature.  So we wait knowing that once it begins a Magnolia will increase in both size and floral performance rewarding us for many years to come…but with Agave, it is once and done.

Agaves are flowering plants, Angiosperms.  Angiosperms all share a broad survival strategy forming complete flowers which produce seed which grow into juvenile plants.  If you follow plants back in time you’ll that find that plants can be broken down into a few large groups.  The largest such group, the Angiosperms or flowering plants, are also the most recent of these…and the most successful.   Angiosperms have seeds encased in a ‘fruit’ that formed within the flower from the ovary.  Gymnosperms, produce seed as well, though their’s are ‘naked’ without a covering fruit, as the plants have no ovary nor true flower. There are other differences between them as well both structural and in the details of their reproductive cycles.  Other plants like ferns don’t produce seeds at all and instead rely on the more ancient process of reproducing directly from spores which grow into an intermediate form, a gametophyte, with one set of chromosomes.  This is the ‘sexual’ stage, either male or female, which mature independently, the male form later fertilizing the female, the product of which grows into the sporophyte, with two sets of chromosomes.   The sporophyte later releases the single sex, single chromosome spore that will grow into the gametophyte, continuing the cycle.  Agave, as a genus, share much with other Angiosperms, they have several distinct peculiarities they share amongst themselves as well.  They are all perennial taking more than a year to mature and flower.  This is a very common attribute.  What sets them apart is that they are monocarpic, they die after flowering once, and, they can take up to 30 years or better, depending on species and growing conditions, to flower.. Continue reading →