Click on images
Scale bar 10mm. Copyright CSIRO
Leaves and Flowers. Copyright CSIRO
10th leaf stage. Copyright CSIRO
Cotyledon stage, epigeal germination. Copyright CSIRO
Desmodium intortum (Mill.) Urb.
Urban, I. (1920) Symbolae Antillanae seu Fundamenta Florae Indiae Occidentalis 8(1): 292. Type: ?.
Hedysarum intortum Mill., Gard. Dict. ed. 8: 11(1768), Type: ?.
Desmodium. Green-Leaved; Grean-Leaved Desmodium; Greenleaf Ticktrefoil; Desmodium, Green-leaf; Beggarlice; Green-leaf Desmodium
Usually grows as a perennial herb with trailing stems but occasionally flowers and fruits as a shrub. A slender vine not exceeding a stem diameter of 2 cm.
Stems and twigs longitudinally grooved, clothed in hooked and sticky hairs. Stipules about 2-6 mm long, usually recurved. Middle leaflet blade about 2.9-7.5 x 1.8-5 cm., lateral leaflet blades about 3.2-4.3 x 1-3.5 cm. Lateral leaflet stalks about 0.2-0.3 cm long, middle leaflet stalk about 0.6-1.1 cm long. Pulvinus present only on the middle leaflet. Lateral veins curving inside the blade margins but not forming loops. Underside of the leaflet blades clothed in pale straight hairs held at an angle of 30-45¦.
Calyx about 5 mm long, sparsely hairy on the outer surface. Corolla about 8 mm long, glabrous. Two calyx lobes fused almost to the tip. Stamens 10, the filaments of nine stamens fused to form a tube. Free part of the filaments alternately long and short. One stamen free. Anthers less than 1 mm long. Ovary clothed in pale prostrate hairs. Ovules about ten. Style and stigma glabrous. Style about 10 mm long.
Pods about 15-50 mm long, segmented, each segment about 4 x 3 mm, clothed in short hooked hairs which cause them to adhere to clothes and animal hairs. Seeds about 2 x 1.5 mm. Cotyledons about 2.5 mm long, radicle curved, about 1 mm long.
Cotyledons about 6 x 3 mm, petioles about 1 mm long. First pair of leaves +/- orbicular, about 6-9 x 6-7 mm, petioles about 6 mm long. Apex obtuse, base obtuse. Stipules filiform, about 1 mm long. Third and fourth leaves simple. Fifth leaf trifoliolate. At the tenth leaf stage: leaflet blades clothed in curved pale hairs on both the upper and lower surfaces. Stipules about 5 mm long, soon turning brown and papery. Stem longitudinally ribbed, clothed in long +/- prostrate hairs and shorter hooked hairs.
Distribution and Ecology
An introduced species originally from Central and South America, now naturalized in NEQ and southwards as far as north-eastern New South Wales. Altitudinal range in NEQ from 700-800 m. Grows along roadsides and the margins of upland rain forest. Also naturalized in New Guinea.
A valuable pasture legume in higher-rainfall areas of the subtropics and high-altitude tropics. Hacker (1990).
Herb (herbaceous or woody, under 1 m tall)
Shrub (woody or herbaceous, 1-6 m tall)