Anarthrophyllum

Taxonomy

Anarthrophyllum G. Bentham In Bentham et J. D. Hooker, Gen. 1: 478. 19 Oct 1865.

Subfamily: Faboideae.
Phylogenetic Number: 3.30.06.
Tribe: Genisteae.
Species Studied - Species in Genus: 13 studied; 15 in genus.

Description

Fruit: A legume; unilocular; 0.7–4 cm long; 0.4–0.9 cm wide; 0.2–0.8 cm thick; 2–9 times longer than wide; 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, or curved (slightly); not plicate; not twisted; asymmetrical, or symmetrical; lanceolate, or linear, or oblong, or ovate, or rhombic; with both sutures parallelly curved to both sutures unequally curved; not inflated; compressed; without beak, or with beak; with solid beak the same color and texture as fruit; tapered at apex, or short tapered at apex; oblique with longitudinal axis of fruit; long tapered at base, or tapered at base; oblique with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous, or coriaceous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; 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 1 suture; apical and down; active; with valves twisting. Replum invisible. Epicarp dull; monochrome; brown; with surface texture uniform; pubescent and indurate, or glabrous to glabrate; with hairs erect; with 1 type of pubescence; tomentose, or villous; 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; thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; coriaceous. Endocarp present; visible; dull; opaque; monochrome; brown; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–8; length transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 1.5 mm long; of 1 length only; thick; straight. Aril absent.

Seed: 2.5–5 mm long; 1.5–4 mm wide; 1.5–1.7 mm thick; not overgrown; not angular; symmetrical (except for hilum); circular, or oblong, or ovate; compressed; without visible 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; reddish brown to brown; glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. 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; apical according to radicle tip but marginal according to seed length; recessed; not within corona, halo, or rim. Lens discernible; 0.9 mm long; with margins straight; wedge-shaped; not in groove of raphe; adjacent to hilum; 0.1 mm from hilum; flush; similar color as testa; darker than testa; 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; tan; inner face flat; glabrous on inner face. Embryonic axis parallel (radicle length parallel to cotyledon length); parallel to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; lobe tip straight; deflexed and parallel to cotyledon length; centered between cotyledons; exceeding length of cotyledons. Plumule moderately developed; glabrous.

Distribution

Chile and Argentina (Andes).

New World; South America (Andes of Chile and Argentina); Argentina.

Generic Notes

Soraru (1974) monographed the genus and illustrated the external characters of its fruits and seeds. Polhill (1981q) and Soraru both noted that Anarthrophyllum seeds often bulge on the side opposite the hilum (or radicle tip). This so-called bulge is just a normal legume seed with the axis parallel to the hilum length shorter than the axis at right angles to the hilum length, viz., the seeds are wider than they are long. Polhill continued that Anarthophyllum is a "very remarkable genus of uncertain affinities, apart from its probable relationship with Sellocharis" (30.07). Polhill (1981q) and Van Wyk (1991) had this genus in Crotalarieae, but later transferred it to the beginning of the Genisteae (30; Polhill, 1994a, 1994b; Van Wyk and Schutte 1995a).

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.