Lotus rigidus (Benth.) Greene

  • Authority

    Isely, Duane. 1981. Leguminosae of the United States. III. Subfamily Papilionoideae: tribes Sophoreae, Podalyrieae, Loteae. Mem. New York Bot. Gard. 25 (3): 1-264.

  • Family

    Fabaceae

  • Scientific Name

    Lotus rigidus (Benth.) Greene

  • Description

    Species Description - Subshrubby, ascending erect, stiff (-flexuous, herbaceous) commonly ephedroid perennial .5-1 (-1.5) m, from a heavy crown. Stems clustered and openly or densely branched, distantly foliose, inconspicuously strigose; internodes usually long, (2-)4-9 cm. Leafstalk 0-5 mm; leaflets 3-4, irregularly pinnate or palmate, obovate to oblanceolate, .5-1.5 cm, 1.5-4 r. Stipules evanescent, black appendages. Peduncles 2-8(-11) cm, often flexuous; umbels with or without a short, subtending bract; flowers (1-)2-3, 1.2-2(-2.4) cm. Calyx tube 4-7 mm, teeth 1.53.5 mm. Corolla bright yellow with regularly graduated petals; standard often bronzed, remaining implicate, not panduriform. Ovary with 17-34 ovules; style confluent as to outline and color but defined in texture, subequal to ovary; stigma scarcely penicillate. Legume erect to divergent, 2-4(-4.5) cm x 3.5-5 mm, slowly dehiscent, persistent into winter; valves glabrate (-strigose), yellow-brown, usually scarcely elastic. Seeds several-numerous, papillose. Simpeteria.

  • Discussion

    Hosackia rígida (1848); L. rigidus (Benth.) Greene (1890); Anisolotus rigidus (Benth.) Rydb.(1906). L. argensis Coville (1893); A. argensis (Coville) Hell. (1913). Semi-ephedroid, often resembling a misarranged bunch of sticks, with elongate, commonly flexuous peduncles and glabrous pods, this desert species is perhaps our ugliest Lotus. It is variable in habit and flower number even within a single population. Though easily recognizable through most of its range, some puzzling populations suggest hybridization with other species.

  • Distribution

    Sw United States and adjacent Mexico. S desert California and w Nevada, e to se Arizona, barely into sw Utah. Deserts and foothills of desert mountains, occasionally of mid-elevations; with greasewood, creosote bush, palo verde and oak chaparral; cliffs, flats, washes; granite, limestone, lava. Ca. 200-4500(-5500) ft. (Feb.-) March-April (-May).

    United States of America North America| Mexico North America|