Studies in the vascular flora of the southeastern United States. VI

Abstract

As part of ongoing efforts to understand, document, and conserve the flora of southeastern North America, we propose a number of taxonomic changes, nomenclatural changes, interpretations of nativity, and distributional accounts. Regarding the Asaroideae (Aristolochiaceae), we support continued recognition of Hexastylis (and other segregates of a very broad Asarum s.l.) at generic rank and make the necessary combinations to continue the use of Hexastylis in southeastern North America floras. In Conoclinium (Asteraceae), we present morphological and distributional evidence corroborating the recent suggestion (based on molecular evidence) that Chapman’s 1878 C. dichotomum is distinct, warrants recognition, and is present as a second Conoclinium in the southeastern North American flora. An analysis of historical accounts of Gaillardia pulchella (Asteraceae) strongly suggests that its modern occurrence east of Texas is adventive, rather than native. Two rare southeastern United States skullcaps, Scutellaria mellichampii and S. ocmulgee (Lamiaceae), have been persistently confused with one another and other species; we present a reassessment of the taxonomic distinction between them, best ways to distinguish them and similar species, and their known distributions. A reassessment of the taxonomy, distribution, and ecology of Linum carteri (Linaceae), a rare southern Florida endemic, confirms that two species should be recognized by modern species concepts; we make the necessary new combination to effect the recognition of two narrowly endemic species. In Andropogon (Poaceae), we propose that A. virginicus var. decipiens warrants recognition as distinct at species rank from other entities in the Andropogon virginicus complex. We also present more comprehensive information on the distributions of four species of “bushy bluestems” (Andropogon glomeratus s.l.), their ecology, and their practical recognition. In the Violaceae, modern reassessment of the taxonomy of many species (especially in the genus Viola) by H.E. Ballard, Jr. and collaborators have been vexed by uncertain application of many “old” names; we here provide a first installment of typifications and nomenclatural interpretations needed to move forward with a modern treatment of the genus in our region. In Xyris (Xyridaceae), we re-establish the generally ignored X. elliottii var. stenotera based on careful and extensive study of its morphology and ecology in comparison to X. elliottii var. elliottii, including a transplant study. English naturalist Mark Catesby (1683–1749) has been honored by having a genus and fifteen species of plants named for him, but most of these honorific names have been constructed in manners contrary to the Shenzhen Code; as these are “errors to be corrected,” we therefore propose to correct and standardize these honorifics by restoring his name ‘catesby-‘ as the root of the names. Similarly, in seven names (variably formed) employed by W.W Ashe to honor his cousin and (later) wife Margaret Haywood Henry (Wilcox) (Ashe), we also standardize and correct the root of the names to be accurately based on her name, ‘margaret-,’ in conformance with the Shenzhen Code.