Monthly Archives: June 2016

Flowering and Its Trigger in Genus Agave

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.

If you follow plants far enough back up their evolutionary ‘tree’ you find plants broken down into flowering plants, that produce seeds (Angiosperms have seeds encased in a ‘fruit’; Gymnosperms have naked or bare seeds) and those that pursue other strategies to propagate themselves.  Plants like Ferns have special organs that produce spores which in turn form an intermediate form, where fertilization takes place, which then grow into an adult plant.  Another step back and plants are divided into vascular or non-vascular, those with specialized cells and structures that include phloem and xylem tissues to move water, nutrients and various metabolites around the plant and those without.   Non-vascular plants are essentially single celled organisms that form colonies or ‘bodies’  with each cell the same, complete and undifferentiated.  Plants as a whole are very unique and resist easy classification.  The botanists among us, in an attempt to better understand this, study plants and their relationships.  Systematics is the study to make sense of the Plant Kingdom, giving it order: what constitutes a plant, how they relate to each other and how they evolved…whom ‘begat’ whom.  Sometimes it would seem that the only common factor shared by all plants is their utilization of chlorophyll, but even this is not universal, because their are saprophytic plants that live off of the carbohydrates and metabolites produced by other plants and some of these are relatively complex Angiosperms.  As gardeners we mostly concern ourselves with vascular plants unless we cultivate mosses, liverworts and such.  Most of us concern ourselves with the flowering plants, though we may also grow spore producers like ferns for their structure and texture.  All of these grow from seeds or spores that carry the DNA that provides a particular species with its ‘script’, a detailed growth plan organisms attempt to follow throughout their lives.  Agaves are vascular Angiosperms that share key flowering characteristics within the genera and more broadly within their family. Continue reading