Psoralea

Taxonomy

Psoralea C. Linnaeus Nom. cons. prop. Sp. Pl. 762. 1 Mai 1753.

Subfamily: Faboideae.
Phylogenetic Number: 3.12.09.
Tribe: Psoraleeae.
Species Studied - Species in Genus: 7 studied; ca. 20 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 0.3–0.6 cm long (including beak); 0.2–0.4 cm wide; 0.15–0.2 cm thick; length less than twice as long as width; with deciduous androecial sheath; with deciduous corolla; with persistent calyx; with calyx longer than fruit; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; symmetrical; elliptic; not inflated; terete; with beak (0.7–0.8 mm long); straight, or declined; with solid beak the same color and texture as fruit; rounded at apex; aligned with longitudinal axis of fruit; rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous, or fragile, thinner than chartaceous, like Trifolium; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin not constricted; margin without sulcus; margin plain; wing(s) absent; nonstipitate; indehiscent. Replum invisible. Epicarp dull; monochrome; gray, or brown; with surface texture uniform; glabrous, or pubescent but soon deciduous; with hairs erect; with 1 type of pubescence; eglandular; without spines; not smooth; with elevated features; veined; irregularly veined (not aligned); not tuberculate; wrinkled; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp absent. Endocarp present; visible; dull; opaque; monochrome; gray; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to epicarp; without wings; entire. Seed(s) 1; length parallel with fruit length. Funiculus straight. Aril present; dry; when dry rim-aril; entire; tan.

Seed: 3–3.5 mm long; 1.7–2 mm wide; 1.5 mm thick; not overgrown; not angular; symmetrical (except hilum); oblong; terete; without visible radicle and cotyledon lobes; without hilar sinus; without umbo on seed faces; without medial ridge on each face. Cuticle not exfoliating; not inflated; not wrinkled. Testa present; without pieces of adhering epicarp; not adhering to endocarp; free from endocarp; dull; not modified by a bloom; colored; monochrome, or mottled; with frequent mottles; brown; with black overlay; glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Raphe not visible. Hilum present; fully concealed; concealed by aril; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 0.6 mm long; with curved outline; elliptic; marginal according to radicle tip; flush; within corona, or not within corona, halo, or rim; corona color lighter than testa. Lens discernible; 0.5 mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; recessed; dissimilar color from testa; darker than testa; black; within corona; corona color lighter than testa. Endosperm present; thin; not pluglike and not resembling tip of radicle; covering entire embryo; adnate to testa. Cotyledons smooth; both outer faces convex; both the same thickness; both more or less of equal length; not folded; margin entire 180 degrees from base of radicle; similar at apex; not concealing radicle; entire over radicle; without lobes; with the interface division terminating in radicle tissue; without margins recessed; yellow; inner face flat; glabrous on inner face. Embryonic axis straight; parallel to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; deflexed and parallel to cotyledon length; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

South Africa.

Old World; Africa, Southwest Asia, China, Indonesia and the Philippines, and Australia.

Generic Notes

Stirton (1981) considered Psoralea to be an artificial assemblage, and redefined it to include approximately 20 species, all endemic to South Africa. He accepted the genus Hallia (12.09) with nine species, but later (Tucker and Stirton, 1991; Crow et al., 1997) expressed the opinion that it is a subgenus of Psoralea. Grimes (1990) concurred with Stirton, and transferred all New World Psoralea species to various genera.

Tribal Notes

Tribe Psoraleeae

Stirton (1981) illustrated seeds and fruits of Amorpheae and Psoraleeae. Since Isely (1962) monographed the tribe for north-central United States the spelling of the tribe name has changed as well as the genera recognized in the tribe. Amorpha (6.04), Dalea (6.08) and Petalostemon A. Michaux (now part of Dalea) are now in the Amphoreae (6), and species in the remaining genus, Psoralea (12.09), have been assigned to several genera treated here. Grimes (1990) noted that this tribe "has been described as having indehiscent fruits. However, in many North American species the fruit is secondarily dehiscent (that is, not along sutures) by transverse rupture of the pod." This technically is not dehiscence.