The Genus Glandularia (Verbenaceae) in North America

Abstract

-The genus Glandularia is recognized as a valid genus distinct from Verbena based on consistent differences in seed morphology, chromosome number, the length of the style, reproductive modes, ploidal levels, and continent of origin. Eight new chromosome counts are given. Also a revision of the taxonomy of the 23 North American species of Glandularia is presented. Two sections, three new species, and one new variety are recognized. In his 13th edition of Linneaus' Systema, Gmelin (1791) established the genus Glandularia with a single species, Glandularia carolinensis based on Walter's Anonymous caroliniensis (1788). From Gmelin's original description, borrowed from Walter, Germen 4 partitum. Stil. 2fidus, glandula inter utramque laciniam media, it seems quite reasonable to assume that the name Glandularia was derived from the glandular appearance of the stigmatic area rather than the glandular hairs of the calyx and floral bract or the glandular appendage on the anther connective as might be supposed. A New World genus of annual or perennial herbs, Glandularia, grows in habitats ranging from the margins of mesic woodlands to dry desert slopes. Species of Glandularia usually grow in an open, often disturbed habitat. Although they can be found in flower during all months of warm weather, they flower primarily in the spring and again in late summer and fall. Glandularia has a disjunct distribution in North and South America. In North America it can be found from Guatemala to South Dakota and from Virginia and Florida to Arizona. South American species are known from Peru, Chile, Uruguay, Bolivia, Paraguay, Argentina, and southern Brazil. Although no complete taxonomic treatment is available for the South American species, there are probably more than fifty. The North American species were monographed by Perry (1933) who recognized 19 species, 6 varieties, and one form under Verbena section Glandularia Schauer. In North America Glandularia grows from Guatemala to South Dakota and from Virginia and Florida to California. The greatest diversity is found in the southwestern United States and in northern Mexico. The taxonomic status of the genus Glandularia has been perceived differently by a number of different authors. The taxa placed here in the genus Glandularia have been given sectional rank under Verbena (Perry, 1933), subgeneric rank under Verbena (Lewis & Oliver, 1961), or generic rank (Schnack, 1944, 1964; Schnack & Covas, 1944, 1946; Small, 1933) based on morpholoXical, anatomical, and cvtological eviI Botany, University of Wyoming, Laramie, WY 82071.