Seeds of South Australia
Cycnogeton alcockiae (Juncaginaceae)
Alcock's Water-ribbons
List of species for Cycnogeton
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Seed collecting:
October to January
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
 Rare   (IUCN: RA d(i,ii))   [undercollected ]
Bridgewater (NCP01)Naracoorte Coastal Plain
 Rare   (IUCN: RA d(i,ii))   [widespread but in small patches; undercollected]
Glenelg Plain (NCP02) 
 Near Threatened
Lucindale (NCP03) 
 Vulnerable   (IUCN: VU B2ab(i,ii,iii))   (Probable Decline)
Tintinara (NCP04) 
 Vulnerable   (IUCN: VU D2)   (Probable Decline)
Kangaroo Island (KAN01)Kanmantoo
 Rare   (IUCN: RA d(ii))   [grows in water; old records; undercollected; lots of habitat]
Fleurieu (KAN02) 
 Vulnerable   (IUCN: VU B2ab(i,ii,iii); D2)   (Definite Decline)   [habitat quality under threat, water flow, climate change]
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)   [habitat quality under threat, water flow, climate change]
St Vincent (EYB02)Eyre Yorke Block
 Regionally Extinct   [regionally extinct]
Murray Mallee (MDD02)Murray Darling Depression
 Data Deficient   [no records, probably here; needs followup]
Lowan Mallee (MDD04) 
 Vulnerable   (IUCN: VU B2ab(i,ii,iii))   (Probable Decline)   [limited habitat; needs water]
Wimmera (MDD05) 
 Vulnerable   (IUCN: VU B2ab(i,ii,iii))   (Probable 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 Cycnogeton]
Name derivation:
Cycnogeton (formerly Triglochin), from the Greek 'cycnos' meaning swan and 'geiton' meaning neighbour, referring to its closeness, taxonomically to Triglochin. Alcockiae named after Kath Alcock of Naracoorte, South Australia, who has had a strong interest in the plants of her area over many years and was the first to alert Botanists to the existence of this species.
Found on Kangaroo Island, southern Mount Lofty Ranges and the South-east in South Australia growing in fresh, still, clear water to 50 cm deep in ephemeral swamps, pools and flats. Also found in Victoria and Tasmania.
Native. Rare in South Australia. Uncommon in Victoria. Common in Tasmania.
Plant description:
Emergent, perennial, aquatic herb with thick, woody, fibre-covered rhizomes and roots ending in tubers which are small, plump, to 28 mm long and 12 mm diameter; plants never robust. Leaves slender, emerged portions floating, never erect to 90 cm long and 8 mm wide. Inflorescence a  slender spike to 67 cm long with a short fruiting part at the tip. Flowering between September and December.
Fruit type:
Yellow-green. tinged  purple globular to depressed globular fruit; mature fruits to 8.7 mm long and 9.9 mm wide with 1–67 per spike. Seed segments (carpels) attached along only the lower part, with the seed-free upper portion sometimes partially spiralled.
Seed type:
Yellow-green segmented seed (carpel) to 8 mm long and 5 mm wide with broad-convex dorsal and lateral ridges.
Embryo type:
Seed collecting:
Collect mature fruits that are turning yellowish-green and seed segments come apart easily, either individually or by breaking off the spike. 
Seed cleaning:
Place the fruit in a tray and leave to dry for 1 to 2 weeks. No further cleaning is required collection consist of mainly individual seeds. If collected with other material, then rub the dried fruit 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 two collections, the seed viability was average to high, ranging from 60% to 100%.
Seeds stored:
LocationNo. of seeds
(weight grams)
of plants
Collection number
Collection location
% ViabilityStorage
2900 (14.67 g)
2900 (14.67 g)
South Eastern
1-Aug-2006100%+5°C, -18°C
BGA1511 (26 g)100+3-Nov-2013KHB805
South Eastern
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
Oct-1498%9 d21 d 500 mg/L gibberellic acid 48 h;
1% agar;
Incubated under winter conditions
Oct-1488%9 d21 d leached in water 4 d;
1% agar;
Incubated under winter conditions
Oct-1486%9 d21 d leached in water 4 d, 500 mg/L gibberellic acid 48 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)