Flora of North America species comparison

Datura wrightii has been introduced worldwide both as an ornamental and unintentionally. In the flora area, it is native in Texas and possibly New Mexico. The combination D. innoxia subsp. quinquecuspida (Torrey) A. S. Barclay is an invalidly published synonym of D. wrightii.

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

Species 14 (8 in the flora).

The large flowers and evening fragrance have assured the cultivation of Datura spp., in particular, D. innoxia, D. metel, D. stramonium, and D. wrightii, throughout the world. Nocturnal anthesis lasts only one night in wild species. Some species of Datura are a sacred component of Native American ritual passage and have been employed since pre-Columbian times (W. E. Safford 1922; W. J. Litzinger 1981; C. E. Boyd 2003). Indigenous and Hispanic peoples employ some species in traditional healing practices for treating wounds and inflammations and for psychotropic effects. Tropane alkaloids, of which more than 30 have been reported in Datura (E. Eich 2008), cause delirium. In particular, atropine, hyoscyamine, and scopolamine are responsible for the anticholinergic properties of some pharmaceutical preparations used in treating motion sickness, broncho- and vasoconstriction, and other ailments.

Some species of Datura have become worldwide weeds (K. Hammer et al. 1983). The commerce of various crop seeds contaminated by D. stramonium is one of the principal causes of its spread during the last century.

Poisonings and deaths from consumption of seeds and/or foliage of Datura spp. are reported for livestock (cattle, horses, swine, and chickens) and humans.

Mexico is considered the center of origin and diversification of Datura (D. E. Symon and L. A. R. Haegi 1991). Prior to human settlement, species of Datura native in what is today southwestern United States included D. discolor, D. innoxia, D. quercifolia, and D. wrightii. Pre-Columbian dispersion of D. wrightii (as a sacred and medicinal plant) and of D. stramonium (as a medicinal plant and a weed associated with Mesoamerican agriculture) is related to settlement histories and migration of various indigenous peoples. Pre-Columbian presence of D. metel (R. Geeta and W. Gharaibeh 2007) and D. stramonium (A. Touwaide 1998) in Eurasia is supported by iconographic, literature, and linguistic sources.

The polymorphism in trichome morphology (for example, glandular versus non-glandular hairs) and density has been shown to have a genetic basis that responds to selection pressures of insect herbivores (N. M. van Dam et al. 1999). Certain seed characters of taxonomic importance such as caruncles (external food bodies rich in amino acids and sugars, also known as elaiosomes) are key to ant-Datura mutualism and maintenance of wild plants populations (D. J. O’Dowd and M. E. Hay 1980). Because of distinctive patterns of variation, certain species of Datura serve as experimental organisms contributing to understanding chromosome diversity, host plant and herbivore interactions, and relationships between various floral characters and hawkmoth pollinators (A. G. Avery et al. 1959; P. L. Valverde et al. 2001; J. L. Bronstein et al. 2009; respectively).

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