Seeds of South Australia
Pultenaea trifida (Leguminosae)
Kangaroo Island Bush-pea
List of species for Pultenaea
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Seed collecting:
December to January
Herbarium region:
Kangaroo Island
NRM region:
Kangaroo Island
IBRA region
Kangaroo Island (KAN01)Kanmantoo
 Rare   (IUCN: RA d(ii))   [endemic to KI; mostly in Flinders Chase]
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 Pultenaea]
Name derivation:
Pultenaea named after Richard Pulteney (1730-1801), an English physician, botanist and biographer of Carl Linnaeus. Trifida from the Latin 'trifidus' meaning split into three; referring to the tri-dentate bracteoles just below the calyx tube. 
Distribution:
Endemic to South Australia and found only on the western end of Kangaroo Island, growing in heath or mallee (Eucalyptus remota) on sands or yellow-brown sandy loams over laterite or ironstone.
Status:
Native. Rare in South Australia.
Plant description:
Erect to prostrate shrub to 1.5 m high, branches with white and rusty hairs. Leaves alternate, to 8.2 mm long and 3 mm wide, ovate-elliptic to orbicular, flat to broadly u-shaped, straight to recurved, sparsely hairy above and densely hairy below. Inflorescences 1 or 2 or a few, crowded terminally on short branches, or axillary with yellow to orange with red striation at front and back pea-flowers, with several bracts and trifid bracteoles inserted just below the calyx tube. Flowering between September and November.
Fruit type:
Hairy brown ovoid pod to 4.5 mm long.
Seed type:
Dark brown with black mottled reniform seed to 2.2 mm long and 1.5 mm wide, with a cream aril.
Embryo type:
Bent.
Seed collecting:
Collect maturing pods, those that are brown or turning brown and contain dark hard seeds inside. 
Seed cleaning:
Place the pods in a paper bag and leave to dry for one to two weeks. Then rub the pods with a rubber bung 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 95%.
Seed germination:
This species has physical dormancy that needs to be overcome for the seed to germinate. The seed coat needs to be ruptured so that water can enter the seed before germination can occur. Methods to rupture the seed coat include scarification with sand paper or nicking the seed coat with a sharp blade or hot water treatment by immersion in boiling water.
Germination table:
DateResultT0T50Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod
Jul-16100%7 d14 d seed coat nicked with scalpel, leached in water 24 h;
1% agar;
Incubated under spring/autumn conditions
Result: Maximum percentage of germination observed.
T0: Number of days before first germinant observed.
T50: Number of days to achieve 50% germination.
Pre-treatment: The initial treatment that the seeds received prior to placement on germination media.
Germination medium: The substrate that seeds were placed on for the duration of the germination experiment.
Incubator conditions:
Photoperiod: The duration of light exposure that the seeds were subject to during a 24 hour period.
Thermoperiod: The constant or diurnal temperatures that seeds were subject to during a 24 hour period.
Winter conditions: 15°C 20 h (3am→11pm); 5°C 4 h (11pm→3am) / 10 h light (8am→6pm); 14 h dark (6pm→8am)
Spring/Autumn conditions: 22°C 12 h (8am→8pm); 10°C 12 h (8pm→8am) / 12 h light (8am→8pm); 12 h dark (8pm→8am)
Summer conditions: 30°C 14 h (6am→8pm); 15°C 10 h (8pm→6am) / 14 h light (6am→8pm); 10 h dark (8pm→6am)