Biorepository Data Portal

Wiggins 1964, Kearney and Peebles 1969

Duration: Perennial Nativity: Native Lifeform: Vine General: A slender, twining or scrambling vine with stems 1-20 dm long from a woody root, minutely puberulent throughout, stipules lance-setaceous, 2-2.5 mm long. Leaves: Petioles slender, 5-12 mm long, petiolule of terminal leaflet from half as long as to equaling petiole; leaflets narrowly ovate-lanceolate to lanceolate, 3-10 mm wide, 1-5 cm long, rounded at base, acute and muctonulate at apex. Flowers: Solitary to few flowered clusters in axils, pedicels 4-5 mm long, calyx tube 1.5 mm long, finely villous with short spreading hairs, teeth linear-subulate, 1.5-2.5 mm long, corolla yellow, 5-6 mm long. Fruits: Pods lunate, 5-7 mm wide, about 2 cm long, finely and closely puberulent, minute beak turned abruptly downward. Ecology: Found on the margins of grassy plains, among shrubs, and on mesas from 3,500-5,500 ft (1067-1676 m); flowers May-September. Distribution: AZ, NM, TX; south to s MEX, and in S. Amer. Notes: Distinguished by being a trailing, but low-growing vine with trifoliate leaves, the dark-green leaflets with punctate (sunk-in) glands, and veins obvious on the bottom surfaces; small, bright yellow flowers; and strongly compressed pods. Specimens in southern Arizona have hairs on the stem that are appressed or subppressed and retrorse, while those further north have spreading or ascending hair. Ethnobotany: Unknown Etymology: Rhynchosia is from Greek rhynchos, horn, beak or snout, while senna from the Arabic name sana. Synonyms: Rhynchosia texana Editor: SBuckley 2010, FSCoburn 2015