Baptisia

Taxonomy

Baptisia É.P. Ventenat Dec. Gen. 9. 1808.

Subfamily: Faboideae.
Phylogenetic Number: 3.29.05.
Tribe: Thermopsideae.
Species Studied - Species in Genus: 7 studied; 17 in genus.

Description

Fruit: A legume; unilocular; 1–7 cm long; 0.2–2.5 cm wide; 0.7–2 cm thick; 2–9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with persistent calyx, or deciduous calyx; with calyx shorter than fruit, or equal in length to fruit; without orifice formed by curving of fruit or fruit segments; straight, or curved (slightly); not plicate; not twisted; symmetrical, or asymmetrical; oblong, or ovate, or circular, or elliptic; with both sutures parallelly curved, or 1 straight and 1 curved suture; widest near middle or D-shaped; usually inflated, or not inflated; terete; without beak, or with beak; straight; with solid beak the same color and texture as fruit; rounded at apex, or long tapered at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; long tapered at base, or rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous, or coriaceous, or membranous (B. megacarpa A.W. Chapman ex J. Torrey & A. Gray); seed chambers externally invisible; margin not constricted; margin without sulcus, or with sulcus; margin plain; wing(s) absent; stipitate, or substipitate; with the stipe 4–13 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; passive. Replum invisible. Epicarp dull, or semiglossy; monochrome; dark to yellowish to reddish to purplish brown, or black (brownish); with surface texture uniform; glabrous, or pubescent and indurate; with hairs appressed (sub), or erect; with 1 type of pubescence; villous; with pubescence gray; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; smooth, or not smooth; with elevated features; veined; reticulately veined; not tuberculate; wrinkled, or rugose; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; (sub-) ligneous, or coriaceous, or chartaceous. Endocarp present; visible; dull; opaque; monochrome; dark to light brown; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 20–30 (estimated); length transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 3.5 mm long; of 1 length only; thick; straight. Aril absent, or present (really funicular remnant); dry; when dry rim-aril; entire; brown.

Seed: 2.5–4.5 mm long; 2–3 mm wide; 1.6–2 mm thick; not overgrown; not angular; asymmetrical; D-shaped (with inconspicuous radicle lobe); compressed; with visible radicle and cotyledon lobes; without external groove between radicle and cotyledon lobes; 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, or glossy; modified by a bloom; colored; monochrome; yellowish to dark brown, or tan, or white; glabrous; smooth, or not smooth; with elevated features; tuberculate (glandular exudates), or blistered cuticle (B. megacarpa A.W. Chapman ex J. Torrey & A. Gray); coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible; from lens to base of seed and terminating (near base); not bifurcating; darker than testa; black; slightly recessed, or flush. Hilum present; partially concealed; concealed by funicular remnant; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; punctiform, or larger than punctiform; 0.3–0.4 mm long; with curved outline; circular; between cotyledon and radicle lobe; recessed; within rim, or within halo (occasionally and faintly); halo darker than testa; rim color of testa. Lens discernible, or not discernible; with margins curved; circular; not in groove of raphe; adjacent to hilum; 2 mm from hilum; flush; dissimilar color from testa; darker than testa; reddish brown; not within corona, halo, or rim. 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 at base of radicle; without margins recessed; yellow, or tan; inner face flat; glabrous on inner face. Embryonic axis deflexed; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; lobe tip curved; deflexed and parallel to cotyledon width; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Eastern Canada, United States, and Mexico.

New World; Canada (Ontario), or United States (Maine to Florida west to Minnesota south to Texas), or Mexico (south of Texas).
 

Generic Notes

Larisey (1940a) and Isely (1981) monographed Baptisia. Occasionally, three cotyledons are found in the seed.

Tribal Notes

Tribe Thermopsideae
Yong-Ming and Ze-Xiang (1990) reevaluated the six genera and forty-seven species in the tribe, and their data confirms Turner (1981). Turner recognized forty-six species and six genera in the tribe.