Amphithalea

Taxonomy

Amphithalea C.F. Ecklon & C.L.P. Zeyher Enum. 167. Jan 1836.

Subfamily: Faboideae.
Phylogenetic Number: 3.25.02.
Tribe: Podalyrieae.
Subtribe: Xiphothecinae.
Species Studied - Species in Genus: 9 studied; 42 in genus.

Description

Fruit: A legume; unilocular; 0.3–1.5 cm long; 0.2–0.7 cm wide; 0.2 cm thick; length less than twice as long as width, or wider than long; with deciduous androecial sheath; with deciduous corolla; with persistent calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; asymmetrical; oblong to ovate, or dolabriform; with 1 straight and 1 curved suture, or both sutures unequally curved, or both sutures parallelly curved, or both sutures nearly straight; widest near middle or D-shaped; not inflated; compressed; with beak, or without beak; straight; with solid beak the same color and texture as fruit; short tapered at apex, or rounded at apex; aligned with longitudinal axis of fruit; short tapered at base, or rounded at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; substipitate, or nonstipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; passive, or active (barely); with valves enrolling (somewhat). Replum invisible. Epicarp dull; monochrome; greenish to dirty or reddish brown (concealed by long straight dense hairs), or gray (because of hairs); with surface texture uniform; pubescent and indurate; with hairs erect; with 1 type of pubescence; tomentose, or sericeous, or villous (A. parvifolia C.F. Ecklon & J.M. Zeyher); with pubescence gray, or golden; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; smooth; not veined; not tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; surface not veined, or uniformly veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; coriaceous. Endocarp present; visible; dull; opaque; monochrome; tan; spongy, or smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–4 (several); length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus of 1 length only; thick, or triangular; straight. Aril present; fleshy; when fleshy cupshaped (with tonguelike extension); entire; covering less than 1/2 of seed; reddish brown.

Seed: 1.5–5.5 mm long; 0.9–3 mm wide; 0.5–1.2 mm thick; not overgrown; not angular; asymmetrical; reniform (oblong), or oblong; compressed; with surface smooth; with visible radicle and cotyledon lobes (to slightly so), or without visible radicle and cotyledon lobes; without external groove between 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 streaked and mottled; with frequent mottles; with frequent streaks; reddish brown to brown; with black overlay; glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible (perhaps concealed by aril). Hilum present; visible; with faboid split; with the lips of the faboid split lighter colored than the rest of the hilum and therefore conspicuous, or the same color as the rest of the hilum (nearly so); larger than punctiform; 0.5 mm long; with curved outline; circular, or elliptic; between cotyledon and radicle lobe; recessed; within rim, or within halo; halo lighter than testa; rim color darker than testa. Lens not discernible (perhaps concealed by aril), or discernible (but concealed under aril). Endosperm present, or absent; thin; 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, or not 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, or green; 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, or linear; lobe tip straight; deflexed and parallel to cotyledon width, or oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons, or 1/2 to nearly length of cotyledons. Plumule rudimentary; glabrous.

Distribution

South Africa (Southern Cape Province).

Old World; Africa (South: Cape).

Generic Notes

Polhill (1981p) noted that Amphithalea may be combined with Coelidium (B.C. Vogel) G.W. Walpers (26.04). Granby (1980) monographed Coelidium, recognizing 19 species (seven new), but Polhill recognized only ca. 15 species. Schutte (1998) carried out a cladistic analysis using morphological and alkaloid characters of Amphithalea and Coelidium with Liparia (26.01) and Xiphotheca (26.03) as outgroups. She concluded that the two genera are synymous, and transferred the Coelidium species to Amphithalea. We are following Schutte.

Tribal Notes

Tribe Podalyrieae

Van Wyk and Schutte (1995a) considered Liparieae and Podalyrieae to each be monophyletic and Sophoreae (2) to be their sister group. Schutte and Van Wyk (1998a, 1998b), using Crotalarieae (27) as outgroup, found that the genera of Liparieae and Podalyrieae coalesced into two closely related clades with Liparia (25.04) in the Podalyria (25.06) clade. This supported earlier suggestions (Polhill, 1976, 1981n, 1981o; Van Wyk and Schutte, 1995a) that Liparieae and Podalyrieae should be merged. Schutte and Van Wyk (1998a, 1998b) merged the two tribes as Podalyrieae, recognized the two clades as subtribes, Xiphothecinae and Podalyriinae, and erected a monotypic tribe for Hypocalytus (3.26.01), Hypocalypteae (26). The generic enumeration and number of species in each genus follows Schutte and Van Wyk (1998a). Van der Bank et al. (2002) carried out further cladistic analyses using DNA, morphological, and chemical data and confirmed the findings of Van Wyk and Schutte.