Those Asparagaceae in Our GardenThursday, June 16, 2016
I always knew that one of my favourite plants and the one that got me into gardening, the hosta, was related to the agave and the yucca and this a plant related to tequila. But on a recent trip to VanDusen I noticed before I entered a sample of plants to note. There was a hosta and it was listed as being from the genus Asparagaceae. So I have investigated and MarieHarrison’s little essay is just right. And with that as an excuse I can run theses photographs of Salem with Hosta montana ‘Aureo Marginata’.
by Marie Harrison (can2grow) January 7, 2014
Several shifts in taxonomy in recent years have sent those of us who try to keep abreast with such changes into a tailspin. Some of the most surprising changes have happened in the Asparagaceae family.
Changes were brought to my attention while writing outlines for Symposia for National Garden Clubs. I had decided to teach the Asparagaceae family to flower show judges. My research of Asparagaceae led to some unexpected revelations. I learned that several genera were in this family other than Asparagus; notably Agave, Chlorophytum, Cordyline, Dracaena, Hyacinthus, Ophiopogon, Liriope, Sansevieria, Yucca, Hosta, and about 116 other species.
Hosta? Really? You’ve got to be kidding! How is it that such seemingly diverse genera are in the same family? Formerly, Hosta was a member of the Liliaceae (lily) family, and then it was assigned its own family, the Hostaceae. Some taxonomists place Hosta in the Agavaceae family. My goodness!
How did this all evolve? Formerly, most taxonomic systems were based on morphology, or the form and structure of a plant. Newer models are molecularly based systems which more accurately reflect the phylogeny (evolutionary descent) of a plant. None of the above assignments were wrong; they were just different and based on the most accurate and reliable information available at the time. Scientists have learned that Hosta and Asparagus share a common ancestor.
I learned the ranks of plants by memorizing this sentence: King David cried, “Oh, for goodness sake!” K is for kingdom, D for division, C for class, O for order, G for genus, and S is for species. These ranks have been significantly changed in the APG III system. Now the rankings are clade, order, family, genus, and species. A clade is a taxonomic group comprising a single common ancestor and all the descendants of that ancestor. Clades within clades, or nested clades, are included. This arrangement helps to show the origin of each species as part of a very large Tree of Life, starting with the first single-celled organisms and including all life forms.
The Asparagaceae family belongs to the clade monocot and the order Asparagales, which has only recently been recognized with the advent of phylogenetics. Older classification systems placed many of the species now within the order Asparagales into the lily family. The recently added Asparagales order contains 14 families, including Amaryllidaceae, Asparagaceae, Asteliaceae, Blandfordiaceae, Boryaceae, Doryanthaceae, Hypoxidaceae, Iridaceae, Ixioliriaceae, Lanariaceae, Orchidaceae, Tecophilaeaceae, Xanthorrhoeaceae, and Xeronemataceae. Within the 14 families are about 1,122 genera and 26,070 species. The Asparagaceae family contains about 126 genera, including Hosta, Sansevieria, and many others.