Hoffmannseggia glauca (Ortega) Eifert
Isley, Duane. 1975. Leguminosae of the United States: II. Subfamily Caesalpinioideae. Mem. New York Bot. Gard. 25 (2): 1-228.
Species Description - Herbaceous, subscapose to caulescent perennial with superficial to usually subterranean caudices deriving from a spreading root system bearing spheroid tubers. Stems (scapes) arising from slender or woody rhizomes, simple to branched, spreading to erect, .5-2(-5) dm, glabrate to villosulous, apically beset with stalked glands. Leaves subbasal or partly cauline; leafstalk (1.5 -)3-7(-9) cm, usually with a few stalked glands; petiole approximating to shorter than rachis; pinnae (2-)3-5(-6) pairs plus 1; leaflets 6-11 pairs, sessile to subpetiolulate, asymmetric, elliptic-oblong, 2.5-6 mm, 2-3 r; blades strigulose to glabrate, without secondary venation or glands. Stipules persistent, ovate-deltoid. Flowers 5-15, glandular, in terminal, exserted, sometimes sinuous, conspicuously glandular, subscapose or leaf-opposed racemes. Pedicels 2-6 mm, recurving after anthesis, not jointed; sepals 6-7 mm, petals orange-yellow (standard with red markings), 10-13 mm, with conspicuously glandular claws, approximating or exceeding the calyx; filaments subequal to petals, red, pubescent and glandular. Legume indehiscent, persistent, pendent-upcurved, oblong to falcate, flat, 2-4 cm long, 6-8 mm wide; becoming obliquely segmented, slightly glandular. Seeds few-many.
H. glauca (Ort.) Eifert (1970) H. densiflara Benth. ex Gray (1852) Larrea densiflora (Benth. ex Gray) Britt. (1930) CNn = 12 (Turner, 1956; as H. densiflora from U.S.). 2n = 24 (Rahn, 1960; as H. falcaria from South America; and others). Hoffmanseggia glauca of North America is not discernibly different from the species called H. falcaria Cav. in South America, and I concur with Eifert (1972 and in litt.) in considering the two conspecific. The traditional epithet densiflora must be abandoned for Larrea glauca Ortega, lying fallow for 170 years, is an earlier legitimate name. Hoffmanseggia glauca is not only the most widespread and aggressive species of Hoffmanseggia but the only one common to both North and South America. It is assumed to be native of the southwestern United States and Mexico, but its range in California is characterized as secondary. Its weedy proclivities and association with the human environment suggest the possibility that it might be an early inadvertant introduction by the Spaniards. On the other hand the alleged use of the tubers for Indian food (Graham, 1941) would seem to provide evidence for its indigenous status in North America. The distributional map (no. 75) shows a hiatus between the extensive northern and western Texas range, and sporadic occurrence in southern Texas, and the same appears on Turner’s map (1959). Perhaps this is an artifact of insufficient collecting. Or possibly H. glauca in its major northern and western phase succeeds in arid, untilled as well as agricultural situations, but is able to compete in southern Texas only in areas of intensive tillage agriculture as exist in the lower Rio Grande Valley. Although Hoffmanseggia glauca is phenotypically of similar aspect through its U.S. range, I have the impression that more California material is of a robust, caulescent type with coarsely, sinuous scapes. There is much populational and individual variation in degree of caulescence, amount of branching and height, and plants range from vividly glandular to almost smooth except for petal claws. Fisher (1892), on the basis of these and other features, recognized some five varieties, but has scarcely been followed by subsequent authors. Of the above characters, those of growth form are probably largely habitat-controlled; the level of glandular adornment is presumably genetic. That Hoffmanseggia glauca has several common names indicates it is known to man whose viewpoint relates almost entirely to its weedy characteristics. But it is a reasonably attractive plant where little else will grow, and it is an excellent soil-binder and ground-cover (Graham, 1941).
S Texas and w Kansas to s California. Abundant, frequent, and conspicuous especially in w and Panhandle Texas, and adjacent New Mexico in disturbed and ruderal areas and locally in farmland soil; urban or rural; also of grazed or disturbed desert scrub, grassland, Prosopis, Agave et al; tolerant of a wide range of soil types, characteristic of heavy alkaline soil in agricultural areas but equally prevalent along roadsides in sandy deserts to deep or drifting sands, recorded from serpentine and i
United States of America North America| Mexico North America| South America|