Sutherlandia

Taxonomy

Sutherlandia R. Brown Nom. cons. In W.T. Aiton, Hortus Kew. ed. 2. 4: 327. Dec 1812.

Subfamily: Faboideae.
Phylogenetic Number: 3.16.03.
Tribe: Galegeae.
Subtribe: Coluteinae.
Species Studied - Species in Genus: 5 studied; 6 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 4–6 cm long; 2–3.5 cm wide; length less than twice as long as width; with persistent androecial sheath, or 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, or circular; with both sutures parallelly curved; inflated; without beak, or with beak; hooked; with solid beak the same color and texture as fruit; short tapered at apex; oblique with longitudinal axis of fruit, or right-angled with longitudinal axis of fruit; tapered at base; oblique with longitudinal axis of fruit, or right angled with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; substipitate; indehiscent. Replum invisible. Epicarp dull, or glossy; monochrome (and transparent); tan to purplish tan; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; veined; reticulately veined; not tuberculate; wrinkled; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp absent. Endocarp absent. Seed(s) 11–17; length transverse to fruit length; neither overlapping nor touching; in 2 or more series. Funiculus 0.5–3 mm long; of 1 length only; nearly thick; straight, or curved. Aril present; dry; when dry rim-aril; entire; tan.

Seed: 2–3.7 mm long; 1.7–3 mm wide; 0.7–1.3 mm thick; not overgrown; not angular; asymmetrical; mitaform, or reniform; compressed; with surface smooth; with visible radicle and cotyledon lobes; with external groove between radicle and cotyledon lobes; with external groove between radicle and cotyledon lobes same color as testa; with shallow 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; black, or brown (blackish to reddish); glabrous; not smooth; with recessed features; pitted with small separate pits; 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; between cotyledon and radicle lobe; recessed; not within corona, halo, or rim, or within halo; halo lighter than testa. Lens discernible, or not discernible; 0.5 mm long; with margins curved; more or less circular; not in groove of raphe; confluent with hilum; barely 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; 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. Plumule rudimentary; glabrous.

Distribution

South Africa extending to Nambia and Botswana; Naturalized on Mexican, Bolivian, and Argentian plateaux.

Old World; Africa (South and extending to Namiba and Botswana).

Generic Notes

Schrirer and Andrews (1992) briefly reviewed the systematics of the cultivated species, and their species number is used. The fruit wall of Sutherlandia is very thin and transparent. Using a dissecting microscope, only a single layer could be discerned, and it was presumed to be the epicarp. It is an unusual condition to have both the mesocarp and endocarp absent.

Tribal Notes

Tribe Galegeae

Traditionally this tribe has been called Galegeae. Reveal (1997) reported that the name Astragaleae was published before the name Galegeae. 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 Astragaleae. In 1999 Reveal (1999) reversed himself, so that this tribe remains the Galegeae. Welsh (1960) reported on the Galegeae of north-central United States. Sanderson and Liston (1995) carried out cladistic analyses of Galegeae genera using molecular data. They concluded that Galegeae is paraphyletic having given rise to tribes Cicereae (20), Hedysareae (18), Trifolieae (21), and Fabeae (19), and therefore requiring a re-evaluation of the circumscription of Galegeae. Heenan (1995, 1998c), utilizing unpublished nuclear ribosomal DNA ITS data, concluded that "Carmichaelia (17.05) is nested within (the) 'Astragalean clade' of Galegeae" and is the sister group of Clianthus. He therefore supported the proposal of Sanderson and Wojciehowski (1996) that Carmichaelieae should not be recognized at tribal level, but rather included in Galegeae.