Ipomoea arborescens var. arborescens
Nomenclature
Ipomoea arborescens (Humb & Bonpl. ex Willd.) G. Don var. arborescens. Ipomoea arborescens (Humb & Bonpl. ex Willd.) G. Don var. glabrata Gentry, Carnegie Inst. Wash.Publ. 527:212. 1942. TYPE: MÉXICO. SONORA: Arroyo Cuchijaqui, Gentry 870 (SYNTYPE: DS, n.v.,cited by McPherson); San Bernardo, Gentry 1158 (LECTOTYPE, here chosen: ARIZ!; ISOLECTOTYPE:MO!).
Convolvulus arborescens Willd., Enum. Pl. 1:204. 1809. TYPE: MÉXICO. GUERRERO: between Acaguisotla and Chilpancingo, Humboldt & Bonpland 3927 (HOLOTYPE: P; microfiche seen).
Ipomoea murucoides var. glabrata Rose, Contr. U.S. Natl. Herb. 1:107. 1891, non A. Gray (1887). TYPE:MÉXICO. SONORA: Alamos, Palmer 316 (HOLOTYPE: US!).
Description
Brit.org/SIDA 21(3): 1283-1292, 2005
Biogeography, Ecology and Natural History
The type locality is between Acapulco and Cd. México, in a mid-elevationseasonally dry tropical zone. The original vegetation at the type locality wasprobably tropical deciduous forest. That region is the southern part of the “typical”habitat of the modern known range of I. arborescens, although the speciesranges into the highlands of Edo. México, Michoacán, and Morelos.
Sonoran desertscrub,thornscrub, tropical deciduous forest, and oak woodland or rarely at the loweredge of “tropical” pine-oak forest
Flowering November–April; near sea level–1800 m;
Brit.org/SIDA 21(3): 1283-1292, 2005
Gentry (1942) called the “smaller, less pubescent-leaved form characteristicof the species throughout the foothill regions of southern and central Sonora”var. glabrata. The trees that extend into the Sonoran Desert North of Hermosilloare probably the same taxon as Gentry’s variety glabrata. Trees of the lowlandand northern Sonora populations have conspicuously lighter-colored (whiter)bark, and flowers with the purple coloration much reduced or lacking whencompared with var. pachylutea.