Botanical art
Prior names
Swainsona microphylla var. affinis
Swainsona microphylla ssp. pallescens
Swainsona microphylla ssp. glabrescens
Swainsona microphylla ssp. affinis
Common names
Common Poison Pea
Small-leaf Swainson-pea
Etymology
Swainsona named after Isaac Swainson (1746-1812), an English scientist and horticulturalist who had a private botanic garden near London. Affinis from Latin meaning allied, that is, relating to or similar to another species.
Distribution and status
Found scattered in the far northern part of South Australia, growing in red sandy loam, often with mulga and callitris, on margins of salt lakes, claypans, sand dunes and creeklines. Also found in Western Australia, Northern Territory, Queensland and New South Wales. Native. Common in South Australia. Common in the other states.
Herbarium regions: North Western, Lake Eyre, Gairdner-Torrens
NRM regions: Alinytjara Wilurara, South Australian Arid Lands
AVH map: SA distribution map (external link)
Plant description
A prostrate perennial herb to 25 cm high, with numerous stems arising from a taproot. Leaves very variable but mostly to 10 cm long with 7-25 leaflets, with largest at the base. Flower racemes to 30 cm long with 5-35 purple, pink, yellow or white flowers. Flowering between June and August. Fruits are broad oblong to spherical pod to 11 mm long and 7 mm wide, much inflated. Seeds are orange to brown mottle, reniform seed to 2 mm long and 1.5 mm wide, with a wrinkled surface. Seed embryo type is bent.
Seed collection and propagation
Collect seeds between September and October. Collect mature pods, those drying off with hard seeds inside. Mature pods can be found lying on the ground next to the plant. Place the pods in a tray and leave to dry fro a week. When dried the pods can become hard and difficult to open. Use a rubber bung to rub the pods or break the pods open with your fingers to dislodge the seeds. Use a sieve to separate the unwanted material. Store the seeds with a desiccant such as dried silica beads or dry rice, in an air tight container in a cool and dry place From one collection, the seed viability was high, at 80%. This species has physical dormancy that need to be overcome for the seed to germinate (e.g. nicking or softening the seed coat).
Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
---|---|---|---|---|---|---|---|
MSB | 2,000 (4.69 g) | 15 | 23-Oct-2007 | DJD914 Lake Eyre | 95% | ||
BGA | 1,200 (3.38 g) | 30+ | 29-Sep-2007 | DJD893 Lake Eyre | 19-Sep-2008 | 80% | -18°C |