Seeds of South Australia
Baumea tetragona (Cyperaceae)
Square Twig-sedge
List of species for Baumea
Click on an image to enlarge it
Seed collecting:
November to March
Herbarium regions:
Southern Lofty, Kangaroo Island, South Eastern
NRM regions:
Adelaide and Mount Lofty Ranges, Kangaroo Island, South East
IBRA regions
Mount Gambier (SVP02)Southern Volcanic Plain
 Vulnerable   (IUCN: VU D2)
Bridgewater (NCP01)Naracoorte Coastal Plain
 Regionally Extinct   [possibly extinct]
Kangaroo Island (KAN01)Kanmantoo
 Vulnerable   (IUCN: VU B2ab(i,ii,iii))   (Probable Decline)   [blue gum plantations, herbicides, pigs - threats]
Fleurieu (KAN02) 
 Near Threatened   (Probable Decline)   [habitat quality decline]
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Near Threatened   (Probable Decline)   [habitat quality decline]
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 Baumea]
Name derivation:
Baumea named after Antoine Baume (1728–1804), a French chemist and inventor. Tetragona from the Greek 'tetra' meaning four and 'gonia' meaning an angle; referring to the square stem.
Distribution:
Found on Kangaroo Island, southern Mount Lofty Ranges and the lower South-east in South Australia, growing in swamps. Also found in Queensland, New South Wales, Victoria and Tasmania.
Status:
Native. Uncommon in South Australia. Rare in Queensland. Common in the other states.
Plant description:
Perennial sedge with slender stems to 120 cm long and 2 mm wide, prominently 4-angled in the upper part, often compressed or subterete in the lower part. Leaves all basal, much wider, acutely 4-angled, sometimes as long as the stem, the tip very acute, the inner ones often reduced to the sheath, lowest bract reduced to its sheath. Flowers in dense panicles with reddish-brown spikelets, close together. Flowering between spring and summer.
Fruit type:
Dense brown heads at the tip of stems.
Seed type:
Pale yellow brown ovoid nut to 2 mm long and 1 mm wide, with a wrinkled surface.
Embryo type:
Capitate.
Seed collecting:
Collect whole heads that are brown, containing dark hard seeds. Not all heads will contain seeds.
Seed cleaning:
Place the heads in a tray and leave to dry for one to two weeks. Then rub the heads with a rubber bung to dislodge the seeds. Use a sieve to separate any 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:
Not all good looking seeds are viable. From one collection, the seed viability was average, at 70%.
Seed germination:
This species is generally difficult to germinate, it has morphophysiological dormancy and complex germination requirements.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA20500 (15.38 g)7-Dec-2006RJB70682
Southern Lofty
1-Aug-200770%-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.