Rhynchosia senna var. azuaensis Grear

  • Authority

    Grear, John W. 1978. A revision of the New World species of Rhynchosia (Leguminosae-Faboideae). Mem. New York Bot. Gard. 31 (1): 1-168.

  • Family

    Fabaceae

  • Scientific Name

    Rhynchosia senna var. azuaensis Grear

  • Description

    Latin Diagnosis - A var. senna et var. angustifolia pube longiori villosa, corolla pallide lutea, legumine longiori, foliolis magis isomorphis inferne tan turn glanduloso-punctatis, patriaque aliena diversa.

    Variety Description - Stems 60-100 cm, prostrate or twining, villous, becoming glabrate, the hairs appressed or spreading. Stipules lanceolate, acuminate, 2-4 mm long, 1-1.5 mm wide. Petioles 7-25(-35) mm, villous or villosulose. Leaflets widely ovate to elliptic or rhombic, often mucronate, base obtuse or truncate, 1-3 cm long, 0.7-2.3 cm wide, puberulous to finely strigulose above, gland-dotted, villous or villosulose beneath, terminal petiolule 4-13 mm, stipels 0.5-1 mm. Inflorescences 15-25 mm, pedicels long and slender, 5-12 mm. Bracts narrowly lanceolate, 2-3 mm. Calyx not exceeding the corolla, villosulose, 7-9 mm, tube 3-3.5 mm, lobes lanceolate, attenuate, 4-6 mm, vexillar sinus 3-3.5 mm. Corolla pale yellow-green, 8-10 mm. Standard suborbicular, villosulose, 8-9 mm long, 6.5-7.5 mm wide, auricles 1 mm, claw 2 mm. Wings widely elliptic, villosulose, 6-7 mm long, 2-2.5 mm wide, claw 2 mm. Keel blades 7-8 mm long, 2-2.5 mm wide, claw 2-2.5 mm. Stamens 7-8 mm. Fruits puberulous or villosulose, 2-3 cm long, 7-9 mm wide, beak 2-3 mm. Seeds 4-5 mm long, 4-5 mm wide, hilum 1 mm.

  • Discussion

    Type. ECUADOR. Azuay, valley of the río Paute and Cuenca, between ríos Azogues and Gualaceo, W. H. Camp E-2325, 26 Mar 1945 (holotype, NY!; isotypes, F!, US!). This variety is rare and has only been collected once, but appears to be sufficiently distinct to warrant varietal recognition. As indicated by the key to varieties, it is most like var senna but differs in villous stems which are never ascending, leaflets glandular-punctate only on their lower surfaces, uniformly yellow corollas and generally larger leaflets and flowers. Its prostrate habit is most like that of var angustifolia. It is interesting to note that the only collection of var angustifolia made in Ecuador is also from the vicinity of Paute in Azuay but it occurs at slightly lower elevations than var azuaensis.

  • Distribution

    Distribution. Known only from the type locality in Azuay, Ecuador (Fig. 19). Found on dry cliffs, rocky hillsides and in occasional ravines at elevations of 21602400 m.

    Ecuador South America|