Leguminosae

Common names

Joint vetch (Australia).

A prostrate herbaceous perennial with a short, tough taproot. Slender stems branch at soil level from a bulbous woody crown. Stem decumbent, to about 6 cm long, pubescent and sometimes also hispidulous; stipules lanceolate, acuminate, 5 to 8 mm long; five to seven (to eight) foliolate the petiole and rachis pubescent like the stem; leaflets obovate-elliptic, about 6 to 10 mm long, 3 to 4 mm wide, obtuse, mucronate, pubescent on both surfaces, the base often oblique, entire; inflorescences usually with one or two flowers developing, longer than the subtending leaves, the peduncles and pedicels hispidulous: the bracts and bracteoles subovate, acuminate, 1 to 2 mm long, about 1 mm wide, pubescent; ciliolate; yellow flowers 7 to 9 mm long, the claw about 1 mm long; the blade orbiculate, 6 to 7 mm in diameter, entire, the outer face puberulent; wings about 7 mm long, the claw 1 mm long, the blade about 6 mm long, 1.5 to 2 mm wide at maximum; keel 7 to 8 mm long, the claws 1 mm long, the blades 6 to 7 mm long, about 2 mm wide; stamens about 8 mm long; legume usually falcate six to eight articulate, the stipe 6 to 14 commonly 8 to 10 mm long, with spreading, glandular hairs, 1.5 to 2 mm, the articles 3 to 4 mm long, 2.5 to 3.5 mm wide, puberulent with crispate or appressed hairs, sometimes also sparsely hispidulous, the body of the articles tending to break away from the margins; seeds about 2 mm long and 1.5 mm wide, dark brown (Rudd, 1955).

The Australian cultivar was collected in Paraguay. It is also recorded in Venezuela (Pittier, 1944).

The only commercially available cultivar (cv. Bargoo) is distinguished from the species by seeds in the sample varying in colour from light yellowish-brown to almost black. There are approximately 375000 seeds per kilogram. Cv. Bargoo is predominantly summer growing, but possesses a degree of tolerance to low temperatures and mild frosts. It is adapted to a variety of poor to moderately fertile soils, derived from sandstone, shale and granite of the Clarence Basin in northern New South Wales, Australia. It responds to superphosphate. It tolerates temporary waterlogging but it does not persist in permanently damp situations. It is easy to establish but requires inoculation with a specific strain of Rhizobium (CB 2312) for best results. However, effective indigenous rhizobia are present in some soils. 
Flowering begins in the spring and continues into autumn. Seed is usually ready to harvest in mid-summer and autumn. The seed pods shatter readily. 
Possesses a high degree of resistance to Amnemus weevil and is resistant to root knot nematodes. 
Very palatable and is grazed selectively by cattle, sheep and marsupials. It withstands heavy grazing and will also persist in rank ungrazed pastures saved for autumn grazing. It combines well with Axonopus affinis, Paspalum dilatatum, P. notatum, Cynodon dactylon and a wide range of native grasses (Mackay, 1973).