Medicago polymorpha L.

Burr Medic

Sp. Pl. 779 (1753) APNI

Taxonomic status:Accepted

Occurrence status:Present

Establishment means:Naturalised

Prostrate or ascending annual herb; stems to c. 60 cm long, glabrous or sparsely hairy; hairs simple. Leaflets obovate to obcordate, 5–30 mm long, 3–22 mm wide, minutely dentate especially towards apex, both surfaces more or less glabrous, upper surface sometimes with darker flecks, apex truncate or emarginate with a terminal tooth; stipules to c. 15 mm long, laciniate, glabrous or lower surface hairy. Inflorescence 2–10-flowered; peduncle 0.5–2 cm long, shorter or longer than subtending petiole. Flowers sub-sessile; calyx 2–5 mm long, teeth equal, as long as or longer than tube; corolla yellow; standard 3–5 mm long; wings longer than keel. Pod with 2–7 loose, thin coils, discoid or cylindric, 2–12 mm long, 3–10 mm diam., glabrous, spiny or tuberculate; coil edge thin; face with 15–20 strongly curved anastomosing veins; marginal vein raised above level of submarginal veins; groove deep; spines to 18 on each side of coil, 0–4 mm long; seeds 3–11, 2–4 mm long, yellow-brown. Flowers mainly Aug.–Nov.

*Brid, *CVU, *DunT, *EGL, *EGU, *GipP, *Glep, *Gold, *HNF, *HSF, *LoM, *MuF, *MuM, *MSB, *NIS, *OtP, *OtR, *RobP, *VRiv, *VVP, *WaP, *WPro, *Wim. Naturalized all States, New Zealand and most other parts of the world. Native to the Mediterranean region. Distributed widely throughout most of Victoria where found mainly in pastures, disturbed ground and along road verges.

3 varieties are commonly recognized (e.g. Heyn 1963, Wiersema et al. 1990) based mainly on the pod size, decoration and number of coils. According to Lesins & Lesins (1979) these varieties are somewhat artificial, and the Australian material has pods with a wide variety of spine lengths occurring in various combinations with the other pod characters.

In addition to the characters given in the key, this species can be distinguished from M. laciniata by the curved anastomosing radial veins on the coil surface and thin partitions between the seeds. In M. laciniata the veins are sigmoidal and hardly anastomosing and there are no seed partitions.

Source: Jeanes, J.A. (1996). Fabaceae. In: Walsh, N.G.; Entwisle, T.J. (eds), Flora of Victoria Vol. 3, Dicotyledons Winteraceae to Myrtaceae. Inkata Press, Melbourne.
Hero image
Distribution map
life Life
kingdom Plantae
phylum Tracheophyta
superorder Rosanae
order Fabales
family Fabaceae
genus Medicago
Higher taxa


Source: AVH (2014). Australia's Virtual Herbarium, Council of Heads of Australasian Herbaria, <>. Find Medicago polymorpha in AVH ; Victorian Biodiversity Atlas, © The State of Victoria, Department of Environment and Primary Industries (published Dec. 2014) Find Medicago polymorpha in Victorian Biodiversity Atlas
  Bioregion Occurrence status Establishment means
Lowan Mallee present naturalised
Murray Mallee present naturalised
Wimmera present naturalised
Glenelg Plain present naturalised
Bridgewater present naturalised
Victorian Volcanic Plain present naturalised
Victorian Riverina present naturalised
Murray Scroll Belt present naturalised
Robinvale Plains present naturalised
Murray Fans present naturalised
Gippsland Plain present naturalised
Otway Plain present naturalised
Warrnambool Plain present naturalised
Goldfields present naturalised
Central Victorian Uplands present naturalised
Dundas Tablelands present naturalised
Northern Inland Slopes present naturalised
East Gippsland Lowlands present naturalised
East Gippsland Uplands present naturalised
Wilsons Promontory present naturalised
Highlands-Southern Fall present naturalised
Highlands-Northern Fall present naturalised
Otway Ranges present naturalised

State distribution

Distribution map
Western Australia
Northern Territory
South Australia
New South Wales
Australian Capital Territory