Seeds of South Australia
Amphibromus pithogastrus (Gramineae)
Plump Swamp Wallaby-grass
List of species for Amphibromus
Click on an image to enlarge it
Seed collecting:
December to January
Herbarium region:
Southern Lofty
NRM region:
Adelaide and Mount Lofty Ranges
IBRA region
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Probable Decline)   [highly restricted, only around Mt Crawford; eastern states sp; likes seepage; perennial; only known from 3 pops, 1 pop gone ]
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 Amphibromus]
Name derivation:
Amphibromus from the Greek 'amphi' meaning double and 'bromus' a grass genus, referring to the spikelets resembling those of the genus BromusPithogastrus from the Greek 'pithos' meaning a large earthenware pot and 'gaster' meaning belly, referring to the swollen lemmas at maturity.
Restricted to a few sites in the southern Mount Lofty Ranges in South Australia, growing in seasonally damp areas. Also found in New South Wales and Victoria.
Native. Endangered in South Australia. Extremely rare in the other States. The SA Seed Conservation Centre collected and banked more than 1,500 seeds for this endangered grass in 2016 with the support of Natural Resources Adelaide & Mount Lofty Ranges. Further collections of this endangered grass will be attempted in 2017 from the two other known historic locations in the Mt Crawford region.
Plant description:
Erect perennial grass to 1 m tall with open sparse and drooping habit. Leaf-blades flat or involute to 20 cm long and 5 mm wide, scaberulous to glabrous. Panicle to 25 cm long. Spikelets to 15 mm long. Glumes similar, thinner than fertile lemma. Lower glume lanceolate, membranous, keeled; 1-keeled, 3–5 -nerved. Upper glume elliptic to 7.3 mm long, membranous, keeled; 1-keeled, 5–7 -nerved. Flowering between October and December.
Fruit type:
Lemma to 7.5 mm long, without keel and with 7-nerves. Lemma apex toothed, 1 -awned. Awn dorsal, 9–16 mm long, with a twisted column. Column 3–5 mm long.
Seed type:
Yellow-brown grain to 4 mm long.
Embryo type:
Seed collecting:
Use hands to gently strip seeds off the mature seed spike that are turning straw colour. Mature seeds will come off easily. Alternatively, you can break off the whole seed spike.
Seed cleaning:
Place the seeds/spike in a tray and leave to dry for two weeks. No further cleaning is required if only seed collected. If seed spikes collected, use hand to strip off the mature seeds. 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 three collections, the seed viability was average to high, ranging from 70% to 100%.
Seeds stored:
LocationNo. of seeds
(weight grams)
of plants
Collection number
Collection location
% ViabilityStorage
BGA920 (2.41 g)3022-Dec-2008DJD1410
Southern Lofty
BGA801513-Dec-2009KHB 347
Southern Lofty
BGA660 (0.82 g)154-Jan-2011KHB347
Southern Lofty
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.
Germination table:
DateResultT0T50Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod
Jul-1793%77 caryopses excised, 500 mg/L gibberellic acid for 24 h;
1% agar;
Incubated under spring/autumn conditions
Jul-1773%77 caryopses excised, 500 mg/L gibberellic acid for 24 h;
1% agar;
Incubated under winter 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)