Electronic Flora of South Australia
Electronic Flora of South Australia
Census of SA Plants, Algae & Fungi
Identification tools

Electronic Flora of South Australia species Fact Sheet

Family: Fabaceae
Swainsona rigida

Citation: J. Black, Trans. R. Soc. S. Aust. 51:380 (1927).

Synonymy: S. laxa R. Br. vat. rigida Benth., Fl. Aust. 2:224 (1864).

Common name: None

Shrub-like herb, glabrous or sparsely hoary with fine short basifixed hairs on the stems, leaves and calyces; stems branched, erect, 50-100 (or more) cm high, rigid, glabrous, faintly striate lengthwise, greyish-green; leaves 3-9 cm long, with 13-15 leaflets often caducous; leaflets oblong to narrow-oblong or obovate-emarginate, mostly 2-5 x 1-3 mm, rarely 7 x 5 mm, glabrous, the terminal leaflet the longest; stipules filiform to lanceolate or narrow-deltoid, 1-4 mm long, caducous with the leaves.

Flowers 9-15 mm long, on 2-3 mm long glabrous to pubescent pedicels, in 15-20-flowered racemes on a rhachis 15-40 cm long, crowded distally, widely spaced on the lower half; bract triangular 1-2 mm long, finally scarious, pubescent; bracteoles deltoid, 0.5-0,8 mm long, clasping the conical base of the calyx; calyx 3.5-5.5 mm long, glabrous or with a few hairs outside, teeth triangular to apiculate, to 1 mm long, pubescent inside, rarely outside, shortly ciliate; standard orbicular, c. 10 mm across, slightly notched, yellow, without calli but with a hollow convexity (sometimes very slightly thickened) above the claw on the inner surface, on a slender claw 2-4 mm long; wings oblong, brownish-purple distally, geniculate near the base of the slender 3-4 mm long claw, auriculate; keel semicircular, shortly and bluntly beaked, slightly turned to one side, yellow, distinctly auriculate above the 3-4 mm long claw, without pouches or folds; ovary stipitate, fusiform, flattened, glabrous, to 20-ovulate; style rigid, thickened at the base, twisted obliquely, grooved and very shortly incurved at the summit, bearded for its whole length, with hair-tufts behind the straight stigma.

Pod stipitate, ellipsoid, 10-20 x 6-9 mm, beaked, compressed, reticulate, glabrous, 1-5-seeded; seed cordiform, brown, smooth, if 1 it is c. 4 x c. 3 mm, if more then smaller.

image of FSA2_Swainsona_rig.jpg
Image source: fig. 339B in J.P. Jessop and H.R. Toelken Ed. 1986. Flora of South Australia (4th edn).

Published illustration: Cunningham et al. (1982) Plants of western New South Wales, p. 420.

Distribution:  predominantly on sand dunes.

  W.Aust.; N.T.; Qld; N.S.W..

Conservation status: native

Flowering time: May — Oct.

SA Distribution Map based
on current data relating to
specimens held in the
State Herbarium of South Australia

Biology: No text

Taxonomic notes: Some specimens with larger leaflets approach S. laxa which has glabrous calyx teeth outside and inside without cilia and wings yellow.

Author: Not yet available

Disclaimer Copyright Disclaimer Copyright Email Contact:
State Herbarium of South Australia
Government of South Australia Government of South Australia Government of South Australia Department for Environment and Water