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Cajanus acutifolius

Family

Fabaceae

Botanical Name

Cajanus acutifolius (Benth.) Maesen

Maesen, L.J.G. van der (1986) Agricultural University Wageningen Papers 85-4: 52. Type: ?.

Synonyms

Rhynchosia acutifolia Benth., Fl. Aust. 2: 266(1864), Type: Northern Territory, Upper Victoria River, Feb. 1856, Mueller; lecto MEL. Fide Reynolds & Pedley (1981) Austrobaileya 1: 423.

Stem

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

Leaves

Leafy twigs longitudinally grooved or striated. Stipules quite small, about 2 mm long, filiform and hairy. Compound leaf petiole often quite long, up to 25 mm long. Middle leaflet (about 45-55 x 13-17 mm) much larger than the lateral leaflets (about 30-40 x 9-15 mm) in each compound leaf. Upper surface of the leaflet blades bullate. Leaflet stalks hairy, middle leaflet stalks about 7 mm long, lateral leaflet stalks about 2 mm long. Lateral veins about 4-9 on each side of the midrib, curving but not forming definite loops inside the blade margin. Small yellow glands visible with a lens on both the upper and lower surfaces of the leaflet blade.

Flowers

Flowers about 14 x 13-14 mm on pedicels about 7-8 mm long. Calyx tube about 3 mm long, lobes about 3.5-4 mm long. Small yellowish glands present on the outer surface of the calyx. Standard with longitudinal brown streaks. Stamens 10, the filaments of nine fused to form a tube about 10-11 mm long, open on one side, and one stamen free. Staminal filaments alternately longer and shorter. Ovary and the base of the style hairy.

Fruit

Pods about 18-23 x 6-8 mm, clothed in hairs and pale yellow glands. Seed 2-3 per fruit. Seeds about 3-4 mm long.

Seedlings

First pair of true leaves simple, opposite, leaf blades about 27 x 8 mm, lanceolate to narrowly ovate. Upper and lower surfaces pubescent. Subsequent leaves trifoliolate. Small pale yellow glands visible with a lens on the upper and lower surfaces of the first pair of leaves. At the tenth leaf stage: upper surface of the leaflet blades with numerous clear or pale yellow globular glands which are visible with a lens. Both the upper and lower leaflet blade surfaces clothed in simple erect hairs. Leaflet stalks densely hairy. Stipules triangular, about 1-4 mm long, densely hairy, appressed to the stem and difficult to see. Stem slightly angled and densely hairy.

Distribution and Ecology

Endemic to Australia, occurs in WA, NT, NEQ and southwards to coastal central Queensland. Altitudinal range from near sea level to 600 m. Usually grows in open forest but also found in monsoon forest, vine thickets and rain forest margins.

Natural History

Not noted to be grazed. Hacker (1990).

WA

X

NT

X

NEQ

X

Herb (herbaceous or woody, under 1 m tall)

X

Shrub (woody or herbaceous, 1-6 m tall)

X

RFK Code

3280