Argyrolobium

Taxonomy

Argyrolobium C.F. Ecklon & J.M. Zeyher Nom. cons. Enum. 184. Jan-Feb 1836.

Subfamily: Faboideae.
Phylogenetic Number: 3.30.03.
Tribe: Genisteae.
Species Studied - Species in Genus: 19 studied; ca. 70 in genus.

Description

Fruit: A legume; unilocular; 0.6–8.5 cm long; 0.3–0.6 cm wide; 0.13–0.25 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; without orifice formed by curving of fruit or fruit segments; straight, or curved (or slightly curved); not plicate; not twisted; asymmetrical, or symmetrical; linear, or oblong, or ovate, or lanceolate, or C-shaped; with both sutures nearly straight, or both sutures parallelly curved; not inflated; compressed, or flattened; with beak, or without beak; with solid beak the same color and texture as fruit; tapered at apex, or short tapered at apex; aligned with longitudinal axis of fruit, or right-angled with longitudinal axis of fruit; short tapered at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; with the apex and base uniform in texture; membranous, or coriaceous; seed chambers externally visible; seed chambers with the raised seed chambers torulose, or not torulose; margin not constricted; margin without sulcus; margin plain; wing(s) absent; nonstipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; active; with valves twisting. Replum invisible. Epicarp dull; monochrome; brown, or tan; with surface texture uniform; pubescent and indurate, or glabrous; with hairs erect, or appressed; with 1 type of pubescence, or 2 types of pubescence; pilose, or villous, or sericeous; with pubescence gray, or golden; with gray hairs on valves and golden hairs on sutures; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; smooth, or not smooth; with elevated features; not veined; not tuberculate; faintly wrinkled; 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; coriaceous. Endocarp present; visible; dull; opaque; monochrome; brown, or tan; smooth and scurfy; without adhering pieces of testa; nonseptate (with slight to well developed scurfy lines between seeds), or subseptate (because of regular intursion of fruit); with septa eglandular; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–14; length oblique to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.1–1.5 mm long; of 1 length only; flattened, or thick; straight, or curved. Aril present; dry; when dry rim-aril, or tongue-aril; entire; tan, or white, or black.

Seed: 1.4–4 mm long; 1.2–2.8 mm wide; 1–1.3 mm thick; not overgrown; not angular, or angular; asymmetrical; oblong, or ovate, or quadrangular, or reniform, or triangular, or circular, or mitaform; compressed, or terete; with surface smooth; with visible radicle and cotyledon lobes, or without visible radicle and cotyledon lobes; with external groove between radicle and cotyledon lobes, or without external groove between radicle and cotyledon lobes; with external groove between radicle and cotyledon lobes same color as testa; 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; glossy, or dull; not modified by a bloom; colored; monochrome, or mottled and streaked; with frequent mottles, or infrequent mottles; with frequent streaks; reddish to greenish brown, or tan (to greenish), or green, or olive, or yellow, or black; with brown overlay (dark), or purple overlay (definite marks to "clouds"), or black overlay; glabrous; smooth, or not smooth; with elevated features; reticulate, or wrinkled; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; punctiform, or larger than punctiform; 0.1–0.5 mm long; with curved outline; circular; between cotyledon and radicle lobe, or apical at apex of radicle tip, or subapical to radicle tip, or marginal according to radicle tip; recessed; within rim; rim color of testa, or lighter than testa. Lens discernible, or not discernible; 0.1–0.5 mm long; with margins straight, or curved; triangular, or oblong; circular, or oblong; not in groove of raphe; adjacent to hilum; 0.2–0.5 mm from hilum; flush, or mounded; dissimilar color from testa, or similar color as testa; darker than testa, or lighter than testa; brown, or tan; not within corona, halo, or rim. Endosperm present; thick; not pluglike and not resembling tip of radicle; covering entire embryo; adnate to embryo. Cotyledons not 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; split over radicle; with lobes; with the interface division terminating at base of radicle; without margins recessed; tan, or yellow, or white; 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; bulbose; lobe tip straight; deflexed and parallel to cotyledon length; centered between cotyledons; 1/2 to nearly length of cotyledons, or equaling length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Mediterranean region to India, Highlands tropical Africa, South Africa, and Madagascar (1 sp.).

Old World; southern Europe to Mediterranean to Russia to Africa to Madagascar to Southwest Asia to India (Africa (north, highlands of tropical, South Africa)).
 

Generic Notes

Polhill (1968) monographed the taxa of tropical Africa, Chaudhary (1997) revised the Indian taxa, and Edwards (1997) revised the species of series Racemosae sensu W.H. Harvey (1862). Van Wyk and Schutte (1990) compared Argyrolobium with several Crotalarieae genera of South Africa, and concluded that Argyrolobium should be part of Crotalarieae, without making the change. Polhill noted that the endocarp often breaks down to form internal partitions.

Tribal Notes

Tribe Genisteae

Traditionally this tribe has been called Genisteae. Reveal (1997) reported that the name Cytiseae was published before the name Genisteae. Following the International Code of Botanical Nomenclature (Greuter et al., 1994), the oldest name for a taxon must be used, so Reveal suggested that this tribe should be called Cytiseae. In 1999 Reveal (1999) reversed himself, so that this tribe remains the Genisteae. Bisby (1981) summarized tribe Genisteae, following the excellent study by Polhill (1976). Bisby correctly noted that "many species have been moved from one genus to another several times and the Cytisus-Genista complex has gained a reputation as a critical group." He continued with an indepth analysis of the tribe. Polhill (1994a, 1994b) and Van Wyk and Schutte (1995a), using chemical and morphological characters, transferred five genera from Crotalarieae (27) to Genisteae: Anarthrophyllum (30.06), Argyrolobium (30.03), Dichilus (30.02), Melolobium, and Sellocharis (30.07). Cristofolini (1997) carried out a cladistic study of the tribe's biogeography, and discussed its early evolutionary history. López et al. (2000) studied the species of this tribe occurring in southwestern Spain and presented detailed descriptions for and a key to them.