Pickeringia

Taxonomy

Pickeringia T. Nuttall ex J. Torrey & A. Gray Nom. cons. Fl. N. Amer. 1: 388. Jun 1840.

Subfamily: Faboideae.
Phylogenetic Number: 3.29.06.
Tribe: Thermopsideae.
Species Studied - Species in Genus: 1 studied; 1 in genus.

Description

Fruit: A legume; unilocular; 2–5 cm long; 0.4–0.5 cm wide; 0.2 cm thick; 2–9 times longer than wide, or more than 9 times longer than wide; with persistent androecial sheath; with deciduous corolla; with persistent calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; slightly curved; not plicate; not twisted; symmetrical; linear; not inflated; compressed; with beak; straight; with solid beak the same color and texture as fruit; long tapered at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; long tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally visible, or invisible; seed chambers with the raised seed chambers not torulose; margin constricted; margin constricted along both margins (by abortion of ovules); margin without sulcus; margin plain; wing(s) absent; stipitate; with the stipe 5–6 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along 1 suture; assumed apical and down; passive. Replum invisible. Epicarp dull; monochrome; light brown; with surface texture uniform; pubescent and indurate; with hairs appressed; with 1 type of pubescence; with pubescence gray; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; not smooth; with elevated features; veined; reticulately veined; not tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present (89–98 are assumed); thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; chartaceous. Endocarp present; visible; dull; opaque; monochrome; tan; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–10; length parallel with fruit length; neither overlapping nor touching, or touching; in 1 series. Funiculus of 1 length only; thick; straight. Aril absent.

Seed: 3–4.2 mm long; 2–2.5 mm wide; 1–1.5 mm thick; not overgrown; not angular; asymmetrical; rectangular, or reniform; compressed; without visible 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; modified by a bloom; colored; monochrome; brownish black; glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible; from hilum through lens and terminating before base of seed; not bifurcating; color of testa; raised. Hilum present; partially concealed, or fully 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; marginal according to radicle tip; recessed; within rim; rim color of testa. Lens discernible; with margins curved; circular; not in groove of raphe; adjacent to hilum; 0.5 mm from hilum; mounded; same color as testa; not within corona, halo, or rim. Endosperm present; thick; not pluglike and not resembling tip of radicle; covering entire embryo; adnate to embryo. 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; 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; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

United States (North central California) to Mexico (northern Baja California).

New World; United States (north central California), or Mexico (northern Baja California).

Generic Notes

Isely (1981) revised the genus. Pickeringia montana rarely sets fruits and seeds, hence the lack of material for our plate. Some authors, including Isely but not Rudd (1968), recognized var. tomentosa, which sets more fruits and seeds. Variety tomentosa cannot be separated from var. montana using morphological characters.

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.