Seeds of South Australia
Swainsona affinis (Leguminosae)
Common Poison Pea
List of species for Swainsona
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Seed collecting:
September to October
Herbarium regions:
North Western, Lake Eyre, Gairdner-Torrens
NRM regions:
Alinytjara Wilurara, South Australian Arid Lands
IBRA regions
Murray Scroll Belt (RIV06)Riverina
 Regionally Extinct   [probably extinct- 1 old record]
Gawler Lakes (GAW03)Gawler
 Rare   (IUCN: RA d(i,ii))
Tallaringa (GVD05)Great Victoria Desert
 Rare   (IUCN: RA d(i,ii))
Simpson Desert (SSD02)Simpson Strzelecki Dunefields
 Least Concern
Dieri (SSD03) 
 Rare   (IUCN: RA d(ii))   [edge of range]
Strzelecki Desert (SSD05) 
 Least Concern
Lake Pure (CHC07)Channel Country
 Least Concern
Mann-Musgrave Block (CER01)Central Ranges
 Rare   (IUCN: RA d(i,ii))
Tieyon (FIN03)Finke
 Rare   (IUCN: RA d(i,ii))
Pedirka (FIN04) 
 Rare   (IUCN: RA d(i,ii))
RSCA map:
Regional Species Conservation Assessments per IBRA subregion. Please click the thumbnail map.
AVH map:
Australian distribution map (external link)
SA Census:
Census of South Australian plants (external link)     [genus Swainsona]
Name derivation:
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:
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.
Status:
Native. Common in South Australia. Common in the other states.
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.
Fruit type:
Broad oblong to spherical pod to 11 mm long and 7 mm wide, much inflated.
Seed type:
Orange to brown mottle, reniform seed to 2 mm long and 1.5 mm wide, with a wrinkled surface.
Embryo type:
Bent.
Seed collecting:
Collect mature pods, those drying off with hard seeds inside. Mature pods can be found lying on the ground next to the plant.
Seed cleaning:
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
Seed viability:
From one collection, the seed viability was high, at 80%.
Seed germination:
This species has physical dormancy that need to be overcome for the seed to germinate (e.g. nicking or softening the seed coat).
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA1200 (3.38 g)30+29-Sep-2007DJD893
Lake Eyre
19-Sep-200880%-18°C
Location: BGA — the seeds are stored at the Adelaide Botanic Gardens, MSB — the seeds are stored at the Millennium Seed Bank, Kew, England.
Number of plants: This is the number of plants from which the seeds were collected.
Collection location: The Herbarium of South Australia's region name.
% Viability: Percentage of filled healthy seeds determined by a cut test or x-ray.