Seeds of South Australia
Gahnia ancistrophylla (Cyperaceae)
Hooked-leaf Saw Sedge
List of species for Gahnia
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Seed collecting:
October to January
Herbarium regions:
Eyre Peninsula, Northern Lofty, Southern Lofty
NRM regions:
Adelaide and Mount Lofty Ranges, Eyre Peninsula, Northern and Yorke
IBRA regions
Fleurieu (KAN02)Kanmantoo
 Near Threatened   [seen on roadsides; comes up after fire]
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Data Deficient   [localised around Onkaparinga NP, could be a decline]
Broughton (FLB02) 
 Endangered   (IUCN: EN D)   (Definite Decline)   [3 plants known]
Eyre Hills (EYB03)Eyre Yorke Block
 Near Threatened   (Probable Decline)   [doesn't mind salt]
Talia (EYB04) 
 Rare   (IUCN: RA d(ii))   (Probable Decline)   [doesn't mind salt]
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. Ancistrophylla  from the Greek 'ancistron' meaning fish-hook and 'phyllon' meaning a leaf; referring to the strongly hooked leaf apex
Distribution:
Found on the southern Eyre Peninsula and southern Mount Lofty Ranges in South Australia with an isolated collection from the mid-north, growing on calcareous and lateritic soils in heath and woodland. Also found in Western Australia and Victoria.
Status:Native. 
Native. Uncommon in South Australia. Rare in Victoria. Common in Western Australia.
Plant description:
Low tussock-forming perennial sedge with slender culms to 80 cm high and 1 mm diameter. Leaf-blades  filiform, channelled, erect, with a hooked or curved apex, smooth, shorter than or equalling inflorescence, sheaths dark brown to blackish, dull. Inflorescence slender, erect, to 40 cm long with spikelets not clustered. Flowering in winter and spring.
Fruit type:
Brown spike.
Seed type:
Dark brown to black three-sided ovoid seed to 1.7 mm long and 1 mm wide, with fine tubercule surface.
Embryo type:
Capitate.
Seed collecting:
Collect heads that are dying off, turning brown and containing hard dark 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 one collection, the seed viability was high, at 85%.
Germination table:
DateResultT0T50Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod
July 201614%56dNA 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 for 6 wks (winter) then 12 hrs (spring)
July 20164%63dNA 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 for 6 wks (winter) then 12 hrs (spring)
July 20162%91dNA Soak in H2O2 for 20 mins then rinse; then 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 for 6 wks (winter) then 12 hrs (spring)
July 20160%NANA 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 for 6 wks (winter) then 12 hrs (spring)
July 20160%NANA Soak in H2O2 for 20 mins then rinse; then 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 for 6 wks (winter) 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)