Seeds of South Australia
Damasonium minus (Alismataceae)
Star-fruit
List of species for Damasonium
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Seed collecting:
December to April
Herbarium regions:
North Western, Gairdner-Torrens, Flinders Ranges, Murray, Southern Lofty, South Eastern
NRM regions:
Adelaide and Mount Lofty Ranges, Alinytjara Wilurara, Northern and Yorke, South Australian Arid Lands, South Australian Murray-Darling Basin, South East
IBRA regions
Lucindale (NCP03)Naracoorte Coastal Plain
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Probable Decline)   [used to be large roadside pops]
Fleurieu (KAN02)Kanmantoo
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)   [edge of range]
St Vincent (EYB02)Eyre Yorke Block
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)   [needs flooding]
Murray Mallee (MDD02)Murray Darling Depression
 Vulnerable   (IUCN: VU D1)   [likes clear standing water; loss of habitat & salinity are threats]
Lowan Mallee (MDD04) 
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Probable Decline)   [likes clear standing water; loss of habitat & salinity are threats]
Wimmera (MDD05) 
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Probable Decline)   [only 1 roadside pop; sensitive spp.]
Murray Scroll Belt (RIV06)Riverina
 Vulnerable   (IUCN: VU D1)   [likes clear standing water; loss of habitat & salinity are threats]
Gawler Lakes (GAW03)Gawler
 Rare   (IUCN: RA d(i,ii))   [no records but occurs here, spread by birds]
Tallaringa (GVD05)Great Victoria Desert
 Rare   (IUCN: RA d(i,ii))   [annual; comes up in good rainfall years; should have state rating]
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 Damasonium]
Name derivation:
Damasonium from the Greek 'damazo' meaning to subdue; because one species was said to overcome poison. Minus meaning small, referring to the species small flower.
Distribution:
Found mainly along the Murray River in South Australia, with scattered records from the South-east and on Eyre Peninsula, growing in shallow and semi-permanent fresh water. Also found in Western Australia, Queensland, New South Wales, Victoria and Tasmania.
Status:
Native. Rare in South Australia. Rare in Western Australia and Tasmania. Common in the other states.
Plant description:
Erect, emergent annual or short-lived perennial to 1 m high with floating and/or emergent leaves. Leaves lanceolate to ovate, obtuse to cordate at the base, to 10 cm long. Flower-spike a panicle to 50 cm high with white to pale-pink flowers, with 3 petals to 6 mm in diameter. Flowering between October and February.
Fruit type:
Pale brown flat capsule to 6 mm long, forming a star-shaped aggregate fruit  to 12 mm diameter.
Seed type:
Dark brown seed to 1.3 mm long and 0.8 mm wide, with a deep wrinkled surface.
Embryo type:
Bent.
Seed collecting:
Collect the star-shaped fruits that are maturing, turning brown and contain hard brown seeds.
Seed cleaning:
Place the fruits in a tray and leave to dry for 1 to 2 weeks. Then rub the dried fruits gently with your hands or 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:
From two colections, the seed viability were high, ranging from 85% to 100%.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA11600 (3.73 g)200+5-Apr-2011DJD2150
South Eastern
1-Jan-2012100%-18°C
BGA4900 (1.32 g)30+9-Feb-2011DJD2120
South Eastern
1-Jan-201285%-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.
Germination table:
DateResultT0T50Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod
May 20110%NANA None
70mm glass petri dishes on 1% w/v agar
Incubated under winter conditions
May 20110%NANA None
70mm glass petri dishes on 1% w/v agar supplemented with 250mg/L Gibberellic acid (pH adjusted to 6.5)
Incubated under winter conditions
May 20110%NANA None
70mm glass petri dishes on 1% w/v agar supplemented with 100mg/L Potassium Nitrate
Incubated under winter conditions
May 20110%NANA None
70mm glass petri dishes on 1% w/v agar supplemented with 100mg/L Potassium Nitrate
Incubated under spring/autumn conditions
May 20110%NANA None
70mm glass petri dishes on 1% w/v agar supplemented with 250mg/L Gibberellic acid (pH adjusted to 6.5)
Incubated under spring/autumn conditions
May 20110%NANA None
70mm glass petri dishes on 1% w/v 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)