Citation: F. Muell., Fragm. Phyt. Aust. 10:6 (1876).

Synonymy: Not Applicable

Common name: Bladder swainsona, rattle pod.

Description:
Shrub-like herb quite glabrous except for a few basifixed hairs on the youngest parts, inside the calyx teeth and occasionally around the stipules; stems to 1 m high, woody at the base; leaves with 11-21 (or more) leaflets, on petioles 5-16 cm long; leaflets oblong-ovate, 10-20 x 5-10mm, obtuse or retuse, slightly apiculate; stipules ovate, 12-15 mm long, obtuse, leafy.

Flowers 15-18 mm long, on 2-4 mm long pedicels conically dilated under the calyx, in 10-20- or more-flowered racemes, on peduncles to 20 cm long and shorter or longer than the corresponding leaf; bract ovate, to 3 mm long, subacute; bracteoles ovate, 1-1.5 mm long, distal on and clasping the dilated tip of the pedicels; calyx campanulate, 5-7 mm long; teeth triangular, shorter than the tube; standard suborbicular, c. 20 mm across, slightly notched, lilac or purple, with 2 strong plate-like yellowish calli above the 2-3 mm long claw; wings shortest, oblong-ovate, auriculate, on a slender short claw, purple distally; keel semi-circular, subacute, shortly auriculate, on a slender claw, 4-5 mm long; ovary stipitate, fusiform, glabrous, 15-30-ovulate; style slender, straight or slightly in. flexed, bearded all the way but more so distally, with a small tuft of hairs behind the straight stigma.

Pod stipitate, roughly elliptic or lunate, 25-50 x 8-20 mm, much inflated, with thin papery walls, often purplish, the suture not impressed, many-seeded; seed reniform to cordate, 2-2.5 x 1.5-2 mm, compressed, dark-brown to blackish, pitted.

Image source: fig. 330B in J.P. Jessop and H.R. Toelken Ed. 1986. Flora of South Australia (4th edn).

Distribution:  S.Aust.: NU, GT, EA, EP, MU.   W.Aust.; N.T. Conservation status: native Flowering time: ?winter and spring.

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

Biology: No text

Taxonomic notes: Shows similarities with S. laxa which is a smaller plant, lacks hairs on the calyx teeth or callosities on the standard, and the pod is smaller, 15-25 mm long, and apparently occurs on the wetter side of the 250 mm isohyet.

Author: Not yet available