Stylosanthes scabra Vogel

Vogel, T. (1838) Linnaea 12: 69. Type: In Brasil. merid.; Sellow leg. in Serra da Moeda, Luschnath ad Bahia.

Shrubby Stylo

Usually flowers and fruits as a shrub 1-2 m tall but also flowers when smaller.

Stipules decurrent on the compound leaf petiole. Leaflet blades about 5-16 x 3-7 mm. Middle leaflet with a short petiole, lateral leaflets +/- sessile. Lateral veins pale on the underside, curving just inside the blade margin but not forming loops.

Flowers almost sessile, concealed within overlapping bracts except at maturity. Upper flowers in each inflorescence are male while the lower flowers are hermaphrodite (?). Calyx about 7 mm long, lobes about 1.5 mm long. Petals: standard about 4 mm x 5-6 mm, yellow-orange but veined with red towards the base; wings about 4 mm long; keel greenish, shorter than the wings. Stamens 10, filaments fused to form a tube, open on the upper side. Stamens dimorphic, short stamens with elongate anthers and long stamens with globular anthers.

Fruits to about 6 mm long, sculptured on the outer surface and densely clothed in pale prostrate hairs. Style hooked, persistent at the apex of the fruit. Seeds two per pod, each almost rectangular, about 2 x 1.5 mm.

Cotyledons obovate, about 4-5 x 3-4 mm, apex obtuse, base auriculate, stipulate. First pair of leaves trifoliolate, leaflet blades hairy, apices aristate. Stipules adhering to the petiole. At the tenth leaf stage: leaflet blades about 25-30 x 10 mm. Stalk of the middle leaflet longer than the stalks of the lateral leaflets. Stipules linear, about 5-6 x 0.5 mm with 1-3 long spine-like hairs on each margin. Stem clothed in fine +/- prostrate hairs and erect spine-like hairs. Seed germination time 21 to 39 days.

An introduced species originally from Brazil, now naturalised in WA, NT, CYP, NEQ, CEQ and southwards to south-eastern Queensland. Altitudinal range in northern Australia from near sea level to 750 m. Usually grows in open forest situations but also found along roads and disturbed areas in rain forest and monsoon forest.

A valuable perennial pasture species for subhumid to semi-arid tropics. Tolerant of low phosphorus soils. Hacker (1990).