Abstract Detail

Floristics & Taxonomy

Ballard Jr, Harvey [1].

Far-reaching taxonomic and evolutionary implications of Ezra Brainerd’s violet research.

While not the first taxonomist to conduct research into North American violets (Viola), Ezra Brainerd’s extensive and pioneering investigations into the genus during the first 25 years of the last century left a prodigious body of research that revealed a substantially diverse genus with quite a few regional endemics on the continent. He published many papers detailing taxonomic distinctions and ecological and evolutionary behavior of members of Viola in our region, managed to disentangle many thorny nomenclatural problems, and described several species and intraspecific taxa, relying on extensive field research and cultivation of thousands of plants and progeny in a garden at Middlebury College in Vermont. He was the first to provide unambiguous morphological and reproductive evidence of frequent hybridization among many North American species, a legacy noted by subsequent violet specialists and lay taxonomists. In his extensive studies of the “acaulescent blue” violets of subsection Boreali-Americanae, he also presented or implied a number of profound and intriguing discoveries concerning species limits and reproductive behavior that have far-reaching taxonomic and evolutionary implications, yet these have not been remarked upon by previous violet specialists or others. A brief history is presented on Brainerd’s research program on North American violets, his study methodologies and major findings, and these are put in a broader context of taxonomic and evolutionary principles. Brainerd’s long-neglected contributions to our understanding of a potentially novel high-polyploid violet group, the “acaulescent blue” violets, encompass evidence for ecological and reproductive isolation that operationally support recognition of narrowly delimited species, a passive mechanism of interspecific gene flow involving hybrid recombination through cleistogamy that has been mistaken for introgression, and a potential polyploid speciation mechanism of intergenomic recombination with subsequent fixation to narrow microhabitat conditions that could represent the driving force of diversification in the lineage.

1 - Ohio University, ENVIR & PLANT BIOLOGY-PORTER H, 315 Porter Hall, Athens, OH, 45701, United States

Keywords:
evolution
allopolyploid
Taxonomy
hybridization
Viola.

Presentation Type: Oral Paper
Session: FTII, Floristics & Taxonomy II
Location: Virtual/Virtual
Date: Wednesday, July 21st, 2021
Time: 1:00 PM(EDT)
Number: FTII003
Abstract ID:595
Candidate for Awards:None