Flora of North America species comparison

Varieties 2 (1 in the flora).

Both varieties of Turnera ulmifolia are homostylous with var. acuta (Sprengel) Urban occurring in Bermuda and the West Indies. Both are used as medicinal plants in the West Indies.

I. Urban (1883) described 12 varieties in Turnera ulmifolia. Experimental studies have demonstrated that this species as he circumscribed it is a polyploid complex in which most of the taxa deserve species status (M. M. Arbo and Aveliano Fernández 1987; Fernández 1997; Fernández and Arbo 2000; J. S. Shore and S. C. H. Barrett 1985; V. G. Solís Neffa and Fernández 2000).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Genera 10, species 226 (2 genera, 4 species in the flora).

The close relationships of Turneraceae with Passifloraceae, Malesherbiaceae, and Violaceae have long been recognized, especially by the presence of cyclopentenoid cyanogenic glycosides and cyclopentenyl fatty acids. These families have traditionally been positioned in Parietales or Violales with other taxa that have parietal placentation; analyses of DNA sequence data indicate that only a subset of the taxa with parietal placentation are closely related. The group that includes Turneraceae is embedded within Malpighiales (V. Savolainen et al. 2000b; D. E. Soltis et al. 2000; O. I. Nandi et al. 1998; M. W. Chase et al. 2002).

(Discussion copyrighted by Flora of North America; reprinted with permission.)