Monographs Details: Acacia angustissima var. chisosiana Isely
Authority: Isley, Duane. 1973. Leguminosae of the United States: I. Subfamily. Mimosoideae. Mem. New York Bot. Gard. 25 (1): 1-152.
Discussion:W Texas, Brewster and Presidio co’s. Desert mountains, and slopes n of Chisos Mts.; usually on igneous soils. 3500-5000 ft. June-August. Also Chihuahua and Coahuila.
This plant is a contorted sub-shrub 2-4 dm high, in general distinguishable from var. texensis not only by its woody habit but by reduction in flower number per head, legume size, leaf size and number of pinnae and leaflets. Probably it represents one or several specialized ecotypes of the texensis complex.