pronounced: kuh-JAY-nuss reh-tick-yoo-LAR-tuss
Cajanus is the Latinized form of the Malay name for the Pigeon Pea; reticulatus is Latin for ‘net-like’. The plant was one of those collected by Banks and Solander at the Endeavour River in 1770.
This plant usually flowers and fruits as a shrub about 1 – 1.5 m tall. The compound leaf petiole is conspicuously grooved on the upper surface; the middle leaflet is usually larger than the lateral leaflets, and on a longer stalk; the leaflet blades are about 3 – 8 by 2.5 – 5 cm, the upper surface bullate, both the upper and lower surfaces clothed in pale hairs. Smaller yellow glands on both surfaces of the leaf blade are visible with a hand lens.
The yellow flowers have pedicels about 5 – 6 mm long, clothed in long erect hairs. The calyx is very hairy, the tube about 3 – 4 mm long, the lobes about 6 – 10 mm long. In the petals, the standard is about 12 mm long, and the keel about 13 mm. There are 10 stamens, the filaments of 9 of them fused to form a tube 9 – 11 mm long open on one side, with one stamen free; the ovary is elongated, and densely hairy; the style is glabrous, 7 – 10 mm long.
The fruits are flat, 2 – 3 cm long, constricted between the seeds, the calyx persistent at the base and the style persistent at the apex. The seeds are transverse, and there are usually 4 or 5 per fruit. Each seed is about 3 mm long, the funicle forming a distinct caruncle or aril at the base.
The plant occurs right across northern Australia, north of a line approximately through Broome, and down the east coast of Queensland, at anything up to 1000 m in altitude. It usually grows in open forest, but is also found in vine thickets and monsoon forest. The plant also occurs in New Guinea. It is a very variable and widely distributed species, apparently not palatable to stock.
The roots were roasted and eaten by the indigenous peoples.
This is a food plant for the caterpillars of several Lepidoptera, including:
• the Small Purple Line Blue Prosotas dubiosa,
• the Dark Cerulean Jamides phaseli, and
• the Cupid Euchrysops cnejus.
