Australian Tropical Rainforest Plants - Online edition

Crotalaria pallida Aiton


Weed
Herb (herbaceous or woody, under 1 m tall)
Shrub (woody or herbaceous, 1-6 m tall)
Click/tap on images to enlarge
Leaves, flowers and fruit. © CSIRO
Scale bar 10mm. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO
10th leaf stage. © CSIRO
Family

Aiton, W. (1789) Hortus Kewensis 3: 20. Type: Nat. of Africa. James Bruce, Esq.

Common name

Rattlepod; Rattlepod, Streaked; Streaked Rattlepod

Stem

Usually flowers and fruits as a shrub 1-1.5 m tall but also flowers as a herb.

Leaves

Compound leaf petiole about 1-6 cm long. Middle leaflet larger than the lateral leaflets. Leaflet blades about 1.5-8 x 0.6-4 cm, broadest at or above the middle. Leaflet stalks about 0.3 cm long. Stipules about 1-3 mm long, recurved, hairy when young, purple at the base but green at the apex.

Flowers

Inflorescences about 15-45 cm long. Flowers borne singly in the axils of deciduous, about 2-5 mm long, bracts. Calyx about 6-7.5 mm long, lobes about as long as the tube. Petals: standard about 10-12 x 8 mm; wings much shorter than the keel; keel about 12-15 mm long. Standard and keel marked by red-purple striations (veins). Stamens 10, dimorphic, five anthers long and basifixed, and five anthers short and dorsifixed. Anther filaments fused to form a tube open on one side. Pollen orange. Ovary densely clothed in white hairs.

Fruit

Pods cylindrical, about 30-45 x 8-9 mm, grooved on one side, clothed in erect hairs. Seeds rattle when pods are shaken. Seeds about 3 x 2 mm, mottled light and dark brown, laterally compressed, +/- hook-shaped or boomerang-shaped. Radicle beside and +/- parallel to the axis of the cotyledons.

Seedlings

Cotyledons about 13-17 x 6-7 mm. First pair of leaves trifoliolate and alternate. At the tenth leaf stage: stipules filiform to narrowly triangular, about 1-5 mm long. Stems, terminal buds and petioles densely clothed in pale brown prostrate hairs. Two small ridges run down the stem from the base of each petiole. Seed germination time 6 to 25 days.

Distribution and Ecology

An introduced species originally from tropical America, now naturalised in WA, NT, CYP, NEQ, CEQ and southwards as far as north-eastern New South Wales. Altitudinal range in CYP and NEQ from near sea level to 800 m. Usually grows as a weed on agricultural land but also found along roads and in disturbed areas in rain forest, vine thickets, open forest and grassland.

Natural History & Notes

This species is suspected of poisoning sheep and cattle. Everist (1974).

Food plant for the larval stages of the Pen Blue Butterfly. Common & Waterhouse (1981).

Used in India as a cover crop. This species is attractive to cattle but fodder and seeds are toxic. Hacker (1990).

RFK Code
3438
Copyright © CSIRO 2020, all rights reserved.