Horticulture/Classifying and naming plants
QUESTION: I searched the 'Net for more information on my new plant—and now I'm not sure what it really is.
Some say that what is called Dorotheanthus bellidiformis Mezoo Trailing Red is actually Aptenia cordifolia 'Variegata', in part because it has an Aptenia's square stems and roundish leaves, while plants of the Dorotheanthus genus have round stems and spatulate leaves.
One person said it couldn't possibly be Dorotheanthus, because 'Mezoo' is a tender perennial, while all Dorotheanthus are annuals.
"Bellidiformis" means daisy, but the flowers on my plant aren't flat like that. They're more like a tuft of bristle.
(I understand that Dr Martin Schwantes named the genus to honor his mother, Dorothea, and for that reason alone, I hope that's what my plant is.)
The arguments for one genus or the other seem to be based mostly on appearance. Is there a less "iffy" way to classify a plant and its ancestry? Some plants seem to change genus every few years. Is there such a thing as genotyping a plant?
Some websites call this plant Dorotheanthus bellidiformis 'Mesbicla' MEZOO TRAILING RED.
I know the first few words are genus, species, cultivar name—but are the words in caps part of its botanical name, or are they a marketing name and not official in any scientific sense?
ANSWER: Hi Janet,
Dorotheanthus is an annual. Aptenia is perennial. They look very similar, but are 2 distinct species. I read that often, one is sold as the other.
Plant genotyping is done all the time, and there are numerous websites and books available online about it.
Mezoo trailing red is a description of a cultivar and is not a part of the botanical name.
The 2 website links above will help you, I think, to determine which one you have.
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QUESTION: Why is there so much dispute over names? Ordinary 'mums used to be Chrysanthemum, then they were Dendranthema—and now they are Chrysanthemum again!
Does genotyping absolutely identify a plant's genus and close relatives? I suppose that genotyping a plant is very expensive and time-consuming. Is that the reason that names are still disputed—because the genotyping for a plant has not yet been done?
Can you recommend a beginning text on this subject?
I found some used equipment for sale - starting in the 5 figure range. Ag Bio-tech labs will genotype one plant for $227.20 - you need 92 samples per SNP (single nucleotide polymorphism).
It's not a quick study. Taxonomy is a field that is constantly changing, as our understanding of plants, animals, and their relationship to each other is constantly changing. Bio-nomenclature is designed to identify a specific plant or animal universally. When I was in college, water snakes were in the genus "Natrix". Now they are "Nerodia". Bobcats were "Felis". Now they are "Lynx". Hundreds if not thousands of plants and animals have undergone name changes (and sometimes back again to the original) as they are being studied. The link below is the Jepson interchange, which lists most recent plant name changes.
As DNA study advances, no doubt there will be more name changing. It will also become more common and less expensive to have seed and plants genotyped by various methods. At present, I would say it is only practical if you are a seed producer, or a major winery, or some other situation where you need absolute proof that what you are selling is exactly what you proclaim it to be.
Hope this helps.