Bituminaria

Taxonomy

Bituminaria L. Heister ex P.C. Fabricius Enum. 165. 1759.

Subfamily: Faboideae.
Phylogenetic Number: 3.12.02.
Tribe: Psoraleeae.
Species Studied - Species in Genus: 1 studied; 2 in genus.

Description

Fruit: A legume; unilocular; 0.4–0.6 cm long (exclusive of fragile beak up to 1 cm long); 0.3–0.4 cm wide; 0.2–0.3 cm thick; length less than twice as long as width; with deciduous androecial sheath; with persistent corolla; with persistent calyx, or deciduous calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; asymmetrical; with 1 straight and 1 curved suture; widest near middle or D-shaped; not inflated; compressed; with beak; declined; with papery fragile beak up to 1 cm long; truncate at apex (exclusive of beak); aligned with longitudinal axis of fruit; rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous, or fragile, thinner than chartaceous, like Trifolium; seed chambers externally visible; margin not constricted; margin without sulcus; margin embellished; margin with prickles; wing(s) absent; nonstipitate; indehiscent, or with all layers dehiscing (secondarily: see Notes). Replum invisible. Epicarp dull; multicolored; mottled; brown, or gray; with red overlay (if spines knocked off); mottling color combination constant; with surface texture uniform, or not uniform, with patches of different texture not restricted to the base and apex; pubescent but soon deciduous and glabrous (except apex); with hairs erect; with 1 type of pubescence; villous; with pubescence gray; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; glandular; with glandular dots (reddish brown); with spines (black on seed chamber); with spines persistent, or broken off and their bases evident; with spines same color as the rest of the fruit, or (or their basal remanent) a different color from the rest of the fruit; not smooth; with elevated features, or recessed features; not veined; not tuberculate; faintly wrinkled; glandularly punctate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; surface not veined; 2-layered; without balsamic vesicles; without fibers; without reniform canals; with spongy layer over solid layer; coriaceous. Endocarp present; visible; dull; opaque; monochrome; grayish black; smooth; without adhering pieces of testa; nonseptate; coriaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings. Seed(s) 1; length parallel with fruit length. Funiculus straight. Aril absent.

Seed: 3.5–4.5 mm long; 2.5–3.5 mm wide; 1.5–2.5 mm thick; not overgrown; not angular; asymmetrical; D-shaped; quadrangular; 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 absent. 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; dark tan; inner face flat; glabrous on inner face. Embryonic axis deflexed; 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; 1/2 to nearly length of cotyledons. Plumule moderately developed; glabrous.

Distribution

Mediterranean Europe, North Africa, and southwest Asia.

Old World; Europe to Mediterranean to Russia to Africa.
 

Generic Notes

Intact seeds of B. bituminosa do not exist free of the fruit, because the testa is fused to the endocarp. Therefore, the testa raphe, hilum, and lens characters could not be scored. The fruits have an aroma reminiscent of fenugreek (Trigonella foenum-graecum, 21.04).

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.