R. Br. in Sturt, Exped. Centr. Aust., Bot.App. 18 (1849) var. laxa.
Synonymy: Swainsona laxa, Swainsona rigida
Common name: Yellow swainson-pea, yellow Darling pea.
Shrub-like herb, completely glabrous except for a few hairs on the youngest parts, glabrescent later; stems erect or ascending, 15-50 cm long, finely striate; leaves 4-17 cm long, with 11-19 leaflets; leaflets obovate or narrow-obovate, 8-27 x 5-15 mm, emarginate, rarely obtuse, glabrous; stipules ovate, acute, 5-15 mm long, with an obliquely decurrent base, broad and leafy.
Flowers 9-11 mm long, yellow, in 12-20-flowered racemes, on peduncles 12 to over 20 cm, elongating in fruit, usually occupying the distal two-thirds of its length; pedicels 2-4 mm long, exceeding by about half the narrow deltoid scarious bract; bracteoles at the base of the calyx, filiform, 0.5-1 mm long; calyx 3-4.5 mm long, contracted into a conical base; teeth triangular, shorter than the tube, glabrous inside and out; standard orbicular, notched, parallel-nerved, without calli, on a rather slender 1.5-2.5 mm long claw; wings shortest, oblong-lanceolate, gently geniculate, auricle big, orbicular, above a slender 1-2 mm long claw; keel about as long as the wings, semicircular, obtuse, shortly auriculate above a short claw; ovary stipitate, fusiform, flattened, to 20-ovulate; style tapering into a slender tip, evenly recurved, scantly bearded all along, few more hairs at the tip and a tuft of hairs behind the straight stigma.
Pod distinctly stipitate, elliptic to lunate, 10-25 x 8-15 ram, much inflated, with thin-papery walls but flattened, suture ridged and not impressed, reticulate, reddish or not, to 10-seeded; seed cordate, c. 2 x c. 1.8 mm, slightly compressed, dark-brown to blackish, pitted.
S.Aust.: LE, EP. Vic.
Flowering time: probably all the year round, depending on rainfall.
SA Distribution Map based
on current data relating to
specimens held in the
State Herbarium of South Australia
Shows similarities with S. colutoides which is a more robust plant having distinct hairs on the inner side of the calyx as well as 2 callosities on the standard and the pod is 25-50 mm long although similar in shape.
Not yet available