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Swainsona pterostylis (DC.) Bakh.f.

Reference
Bot.Jahrb.Syst. 86:394-395 (1967)
Conservation Code
Not threatened
Naturalised Status
Native to Western Australia
Name Status
Current

Low-growing or prostrate perennial, herb, 0.15-0.4(-1.3) m high. Fl. purple-violet, Apr to Oct. Red or white sand, clay, red loam. Coastal sandhills, claypans, sandplains, creeklines, floodplains.

Grazyna Paczkowska, Descriptive Catalogue, 5 August 1996
Image

Scientific Description

Erect or prostrate,spreading or scrambling, herb. Stems terete, not spiny, hairy; pustules or glands absent. Leaves or phylloclades clearly present, compound, alternate, continuous with stem, 50-115 mm long, hairy, with simple hairs, flat with flat margins; margins entire; tubercles absent, leaflets 13-19, pinnately arranged, terminal leaflet present, stalked; pustules or glands absent. Stipules present and persistent to older leaves. Pedicel present, 3-4 mm long, hairy. Bracteoles present and persistent, 1-1.2 mm long, hairy, not striate. Calyx 4.5-5.5 mm long, not accrescent, hairy, with simple hairs, ribless; pustules or glands absent. Corolla 9-13.5 mm long, uniformly coloured, purple; claws present; standard 7-13 mm long, glabrous, not auriculate, wings 6-9 mm long, auriculate, keel 8-10 mm long, not beaked, auriculate, glabrous. Stamens ten; anthers 0.5-0.7 mm long, at two different levels (filaments alternately long and short); filaments united in an open sheath with one free stamen, 6-8 mm long. Ovary stipitate, hairy or glandular; style 10-14 mm long, hairy or glandular towards the base, bearded (with a tuft of hairs at apex), flattened at apex. Fruit dehiscent (a pod or follicle), 10-12 mm long, 6-7 mm wide, stipitate, not constricted between the seeds, round in cross-section, glabrous. Flowers in April, May, June, July, August, September and October. Occurs in the Northern, Eremaean and South-West Botanical Province, in the Great Sandy Desert, Pilbara, Carnarvon, Gascoyne, Yalgoo, Murchison, Dampierland, Geraldton Sandplains and Avon Wheatbelt IBRA regions.

C. Hollister and K.R. Thiele, 24 October 2023

Distribution

IBRA Regions
Avon Wheatbelt, Carnarvon, Dampierland, Gascoyne, Geraldton Sandplains, Great Sandy Desert, Murchison, Pilbara, Yalgoo.
IBRA Subregions
Ashburton, Augustus, Cape Range, Carnegie, Chichester, Edel, Fortescue, Geraldton Hills, Hamersley, McLarty, Merredin, Pindanland, Roebourne, Western Murchison, Wooramel.
IMCRA Regions
Pilbara (nearshore), Shark Bay.
Local Government Areas (LGAs)
Ashburton, Broome, Carnarvon, Cue, East Pilbara, Exmouth, Karratha, Meekatharra, Mingenew, Murchison, Northampton, Port Hedland, Shark Bay, Upper Gascoyne, Wiluna.