Crotalaria retusa

wedge-leaf rattlepod


Crotalaria retusa


pronounced: kroh-tuh-LAH-ree-uh re-TOO-suh

(Fabaceae — the pea family)

subfamily: Faboideae - the bean subfamily


common name: wedge-leaf rattlepod


native 4Crotalaria comes from the Greek κροταλον (krotalon), a rattle or castanets, referring to the sound the dried seed pods make when shaken; retusa is from the Latin retusus, dull, blunt.

This is a native of the warm areas of Africa, Asia, and Australia, but the exact native range is obscure: it is widely naturalized in the tropics.

The stems are erect, slightly ridged, and pubescent. The leaves are alternate, simple, oblanceolate, up to 9 cm long and 1 – 4 cm in width, with the lower surfaces shortly pubescent; there are 5 – 8 veins on each side of the midrib. The apex of the leaves is rounded, or occasionally acute, usually retuse, with the base cuneate. The petioles are anything up to 3 mm long, and there are tiny stipules, only half a millimetre in length.

The flowers are borne in a terminal raceme; they are typical pea flowers, yellow with fine purple lines near the base. The standard is about 1.5 cm long and 2 cm wide, the wings oblong-lanceolate, about 1.5 cm long by 1 cm wide; the keel petals short, the beak twisted, the margins ciliate.

The seed pods are inflated, green, maturing to dark brown or black, 3 – 4 cm long, with the 20-or-so tan to black seeds in each pod.

Crotalaria species are used as food plants by the larvae of some species of Lepidoptera, including those of:
      • the Pea Blue Lampides boeticus;
      • the Crotalaria Podborer Argina astraea; and
      • the Crotalaria Moth Utetheisa lotrix.

dangerous 2Most parts of the plant are toxic to livestock. Although the plant is cultivated in some parts of the world, here it is found as a weed of roadsides and wastelands. In parts of New Guinea it is quite a serious weed. Being a legume, it does fix its own nitrogen from the atmosphere, and so can grow in very poor soils.


Photographs taken in Picnic Bay 2009-2012, Nelly Bay & Arcadia 2014
Page last updated 3rd December 2018