Tephrosia virginiana (L.) Pers. - Goat's Rue
Family - Fabaceae
Stems - To 50cm tall, from caudex and long woody roots, multiple from base, herbaceous, densely villous to hirsute, erect to reclining or sprawling, often reddish-purple, simple to few branching.
Leaves - Alternate, odd-pinnate, stipulate. Stipules to 11mm long. Leaflets opposite to subopposite, with short petiolules or sessile, 11-25, oblong-elliptic, mucronate to apiculate, to 2.5cm long, 1cm broad, entire, sericeous below, pubescent above, with prominent midrib. Terminal leaflet typically emarginate, cuneate, slightly smaller than lateral leaflets.
Adaxial leaf surface.
Abaxial leaf surface.
Abaxial leaf surface.
Inflorescence - Terminal compact racemes to -10cm long (tall). Pedicels to 1cm long in flower, hirsute to densely villous. Each flower subtended by a bract to +1cm long. Bracts pubescent to villous.
Flowers - Corolla papilionaceous, bicolored, to +1.5cm long and broad. Standard yellow to tannish, 1.5cm broad, +1.5cm long, with slight purple mottling at base, densely pubescent externally, glabrous internally. Keel and wings pink to rose, to 1.5cm long, glabrous. Stamens monodelphous(but sometimes appearing diadelphous), the tube(filaments) glabrous and white. Ovary canescent, 8-9mm long. Style upcurved, bearded, green, 8mm long. Calyx tube purplish above, green below, canescent externally, glabrous internally, to +3mm long. Upper lip 2-lobed. Lobes acuminate or attenuate, to 4mm long. Lower lip 3-lobed. Lobes acuminate to attenuate, to 6mm long. Fruit to +5cm long, 5mm broad, compressed, brownish with some black, canescent.
Flowering - May - August.
Habitat - Rocky open woods, glades, prairies.
Origin - Native to U.S.
Other info. - T.
virginiana is a very striking and important plant. The large
roots contain nitrogen fixing bacteria and also rotenone, the latter being
used as an insecticide and fish poison. Traditionally, the plant had been
used to treat many ailments such as tuberculosis, rheumatism, and bladder
troubles. The plant has also been studied in cancer research.
Photographs taken at the Current River Conservation Area, Reynolds County, MO., 6-13-01, and in Alley Spring, MO., 6-3-03.