Aeschynomene falcata (Poir.) DC.
Note: The genus, Aeschynomene, is separated into two sections: Aeschynomene and Ochopodium. The former encompasses species predominantly from wet environments, such as Aeschynomene americana, Aeschynomene indica and Aeschynomene villosa, while the latter includes a number of dryland species, such as Aeschynomene brasiliana, Aeschynomene falcata and Aeschynomene histrix.
Basionym: Hedysarum falcatum Poir.
Family: Fabaceae (alt. Leguminosae) subfamily: Faboideae tribe: Dalbergieae.
Stems decumbent, to about 1 m long and 1‒3 mm diameter, pubescent and sometimes also hispidulous. Stipules lanceolate, acuminate, 5–8 mm long, 1–1.5 mm wide at base, subglabrous to hispidulous, ciliolate; leaves 5–7 (‒9)-foliolate, the petiole and rachis pubescent like the stem; leaflets obovate-elliptic, about 6–12 mm long, 2.5–4 mm wide, obtuse, mucronate, pubescent on both surfaces, the base often oblique, entire. Inflorescences usually with only 1 or 2 flowers developing, longer than the subtending leaves, the peduncles and pedicels hispidulous, the bracts and bracteoles subovate, acuminate, 1–2 mm long, about 1 mm wide, pubescent, ciliolate; flowers 7–9 mm long; calyx 3–4 mm long, pubescent, ciliate; standard 7–9 mm long, the claw about 1 mm long, the blade (standard) orbiculate, 6–7 (‒9) mm in diameter, entire, the outer face puberulent; wings about 7 mm long, the claw 1 mm long, the blade about 6 mm long, 1.5–2 mm wide at maximum; keel 7–8 mm long, the claws 1 mm long, the blades 6–7 mm long, about 2 mm wide; stamens about 8 mm long. Legume 15‒30 mm long, usually falcate, (4‒) 6–8-articulate, the stipe (6‒) 8–10 (‒14) mm long, with spreading, glandular hairs 1.5–2 mm long, the articles 3–4 mm long, 2.5–3.5 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, commonly dark brown, but varying from light yellowish-brown to almost black; 370,000‒450,000 seeds/kg.
Aeschynomene falcata: native to S America; leaves 5‒9 (‒10)-foliolate, pinnae pubescent on both surfaces; (4‒)6‒8-articulate, articles 3‒4 mm long, 2.5‒3.5 mm diameter, stipe (6‒) 8‒10 (‒14) mm long.
Aeschynomene elegans: native to S America; leaves commonly (7‒) 10‒16-foliolate, pinnae upper surface sparsely pubescent to glabrous, the lower moderately pubescent; legume (5‒) 6‒8 (‒9)-articulate, articles 2‒2.5 mm diameter, stipe (8‒) 10‒15 mm long.
Description based on Rudd (1955).
Asia: torog-torog (Bikol, Philippines); turi rawa (Javanese, Indonesia)
English: Australian joint-vetch, jointvetch
Latin America: carrapicho, isca, sensitiva-mansa (more appropriately applied to Aeschynomene elegans, Aeschynomene sensitiva) (Brazil)
South America: Argentina (Chaco (e.), Corrientes, Misiones), Bolivia, Brazil, Colombia, Paraguay
Asia: Indonesia, Philippines
Australasia: Australia (NSW, Queensland (s.e.))
Sown as a permanent component of low input pastures (e.g. Axonopus, Imperata, Heteropogon).
Originates from areas with rainfall to about 1,800 mm/yr. Usually recommended for sowing between about 900 and 1,500 mm average annual rainfall. Persists down to about 700 mm/yr, but usually less productive. Very drought hardy, and continues to grow during the dry season. Prefers good drainage, although will tolerate temporary waterlogging.
Native to subtropics and upland tropics, from about 7º N in Colombia to 28º S in Argentina, and from <100 m asl in the subtropics to 2,000 m asl in the tropics. This equates to an annual average temperature range of about 19‒22 ºC. Tops are burnt by frost but plants recover with onset of warm conditions. Early season growth varies with ecotype.
Full sunlight to moderate shade.
Flowers and sets seed throughout the growing season.
Under heavy grazing, the plant adopts a low rosette growth habit, but still produces sufficient seed to allow spread and long-term persistence.
Recovers well from annual burning of pastures, fire stimulating hard seed breakdown and potential recruitment.
Has a high level of hard seed, which is usually scarified in the harvesting and threshing process. Establishes into burnt native pasture or after soil disturbance, although, if seed is expensive, a good seedbed is preferable. Somewhat promiscuous, but nodulates most effectively with Aeschynomene inoculum CB 2312 or common cowpea type rhizobia.
Persists on infertile soils but responds to low inputs of phosphorus if levels are low (say 5‒10 ppm available P). May require additional Mo on some acid soils.
Combines with low growing dense forages and more open erect grasses in low fertility situations. Favoured by heavy grazing.
Possesses a high degree of resistance to Amnemus weevil (Amnemus quadrituberculatus) and is resistant to root knot nematodes (Meloidogyne spp.). Can be attacked by anthracnose (Colletotrichum sp.) during extended wet weather. Seedlings are susceptible to damping off caused by fungi such as Rhizoctonia sp. and Pythium sp.
Seed is eaten and spread by cattle into new forages. In larger areas with an environment well suited to , seedlings can appear in significant numbers considerable distances from the source stand of seed.
Low - spreads easily, but not aggressive.
Yields generally low, around 1‒2 t DM/ha, up to 5 t DM/ha under good conditions.
Augments low quality grass pastures.
Self-pollinating; 2n = 20.
Flowering continues for most of the growing season, declining with the onset of cool conditions. Gives better seed production when supported by a framework of erect, fine-stemmed, relatively low-growing grass. Can be harvested with direct heading and suction harvesting. About 60 kg seed/crop, possibility of 2 crops/year. Up to 680 kg/ha from small plots. Anthracnose in the growing tips and pod shattering reduce yields.
Susceptible to acifluorfen, 2,4-DB and 2,4-D, and tolerant of bentazone, fluazifop-butyl and sethoxydim.
Cook, B.G. (1992) Aeschynomene falcata (Poiret) DC. In: Mannetje, L.’t and Jones, R.M. (eds) Plant Resources of South-East Asia No. 4. Forages. Pudoc Scientific Publishers, Wageningen, the Netherlands. p. 39–40. edepot.wur.nl/327785
Hennessy, D.W. and Wilson, G.P.M. (1974) Nutritive value of Bargoo jointvetch (Aeschynomene falcata) and companion grasses when fed to sheep. Journal of the Australian Institute of Agricultural Science 38:82–84.
Jones, R.M., McDonald, C.K., Clements, R.J. and Bunch, G.A. (2000) Sown pastures in subcoastal south-eastern Queensland: Pasture composition, legume persistence and cattle liveweight gain over 10 years. Tropical Grasslands 34:21–37. bit.ly/2J5MEiB
Rudd, V.E. (1955) The American species of Aeschynomene. Contributions from the United States National Herbarium 32:1–172. hdl.handle.net/10088/27083
Wilson, G.P.M. (1980) Bargoo jointvetch: tough legume for tough country (New South Wales). Agricultural Gazette of New South Wales 91:51–53.
Wilson, G.P.M., Jones, R.M. and Cook, B.G. (1982) Persistence of jointvetch (Aeschynomene falcata) in experimental sowings in the Australian subtropics. Tropical Grasslands 16:155–156. bit.ly/2QAZo5b