Seeds of South Australia
Gahnia sieberiana (Cyperaceae)
Red-fruit Saw-sedge
List of species for Gahnia
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Seed collecting:
November to March
Herbarium regions:
Southern Lofty, Kangaroo Island
NRM regions:
Adelaide and Mount Lofty Ranges, Kangaroo Island
IBRA regions
Glenelg Plain (NCP02)Naracoorte Coastal Plain
 Vulnerable   (IUCN: VU D1+2)   [(no records) THorn & BHaywood have records]
Kangaroo Island (KAN01)Kanmantoo
 Near Threatened   [western end; needs lots of water; roadworks, herbicides, blue gums - threats]
Fleurieu (KAN02) 
 Least Concern
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Near Threatened
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 Gahnia]
Name derivation:
Gahnia named after Dr. Henricus Gahn, 19th century Swedish botanist and student of Linnaeus. Sieberiana named after Franz Wilhelm Sieber (1789-1844), a Bohemian botanist and collector who travelled to Europe, the Middle East, South Africa and Australia.
Distribution:
Found on Kangaroo Island, southern Mount Lofty Ranges and the lower South-east in South Australia, growing in damp to wet sites in heathlands and forest. Also found in Queensland, New South Wales , Victoria, Tasmania, New Guinea and New Caledonia. 
Status:
Native. Common in South Australia. Common in the other states.
Plant description:
Tall, tussock-forming perennial sedge with culms to 2.5 m high and 50 mm diameter. Leaf-blades flat, recurved, scabrous, about as long as culm. Inflorescence erect or somewhat spreading, to 100 cm long, brown to black. Flowers in spring and summer.
Seed type:
Red three-sided ovoid seed to 4 mm long and 2 mm wide, smooth and shiny.
Embryo type:
Capitate.
Seed collecting:
Collect heads that are dying off and turning brown with obvious hard red 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:
From three collections, the seed viability were high, ranging from 80% to 100%.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
32108 (144.48 g)
31800 (143.4 g)
~5015-Dec-2004MKJ 53
Kangaroo Island
28-Mar-2006100%-18°C
BGA35000 (153.94 g)20+12-Feb-2008Cleland CP
Southern Lofty
20-Jul-200980%-18°C
BGA21700 (88.26 g)23-Jan-2008DJD1044
Southern Lofty
20-Jul-200985%-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
July 201668%56d84d Soak in H2O2 for 20 mins then rinse; soak in 10% smoked water for 24 hrs
1% water agar
15˚C for 20 hrs, 5˚C for 4 hrs (winter) for 6 wks then 22˚C for 12 hrs, 10˚C for 12 hrs (spring)      /  10 hrs (winter) for 6 wks then 12 hrs (spring)
July 201662%56d84d Dry heat at 90 degrees C for 15 mins; Soak in H2O2 for 20 mins then rinse; soak in 10% smoked water and 500 mg/L GA for 24 hrs
1% water agar
15˚C for 20 hrs, 5˚C for 4 hrs (winter) for 6 wks then 22˚C for 12 hrs, 10˚C for 12 hrs (spring)      /  10 hrs (winter) for 6 wks then 12 hrs (spring)
July 201638%63dNA Soak in H2O2 for 20 mins then rinse; soak in 500 mg/L GA for 24 hrs
1% water agar
15˚C for 20 hrs, 5˚C for 4 hrs (winter) for 6 wks then 22˚C for 12 hrs, 10˚C for 12 hrs (spring)      /  10 hrs (winter) for 6 wks then 12 hrs (spring)
July 201634%56dNA Dry heat at 90 degrees C for 15 mins; Soak in H2O2 for 20 mins then rinse
1% water agar
15˚C for 20 hrs, 5˚C for 4 hrs (winter) for 6 wks then 22˚C for 12 hrs, 10˚C for 12 hrs (spring)      /  10 hrs (winter) for 6 wks then 12 hrs (spring)
July 201614%84dNA Soak in H2O2 for 20 mins then rinse
1% water agar
15˚C for 20 hrs, 5˚C for 4 hrs (winter) for 6 wks then 22˚C for 12 hrs, 10˚C for 12 hrs (spring)      /  10 hrs (winter) for 6 wks then 12 hrs (spring)
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)