Seeds of South Australia
Hydrocotyle diantha (Umbelliferae)
Kangaroo Island Pennywort
List of species for Hydrocotyle
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Seed collecting:
October to December
Herbarium regions:
Yorke Peninsula, Kangaroo Island
NRM regions:
Kangaroo Island, Northern and Yorke
IBRA regions
Kangaroo Island (KAN01)Kanmantoo
 Vulnerable   (IUCN: VU D2)   [in Kelly Hill; tiny & cryptic; salinity & changed hydrology an issue; could be EN D]
Southern Yorke (EYB01)Eyre Yorke Block
 Vulnerable   (Definite Decline)   [One known population in Innes National Park]
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 Hydrocotyle]
Name derivation:
Hydrocotyle from the Greek 'hydro' meaning water and 'kotyle' meaning a dish or plate; alluding to the shape of the leaves which are slightly depressed in the centre. Diantha from the Greek 'dis' meaning twice and 'anthos' meaning flower.
Found only on the tip of the Yorke Peninsula and the western end on Kangaroo Island in South Australia, growing in swamp flats and heath under Melaleuca and Hakea thickets. Also found in Western Australia.
Native. Very rare in South Australia. Common in Western Australia.
Plant description:
Tiny prostrate annual herb spreading to 10 cm wide but not rooting at the nodes. Leaves to 5 mm wide with 5-7 lobes. Flowers tiny yellowish green. Flowering between September and November.
Fruit type:
Yellow-orange cluster of tiny fruits each with two seed segments.
Seed type:
Orange wedge-shaped seed to 1.5 mm long and 1 mm wide, with 3 slender ribs and a wing along the outer edge.
Embryo type:
Linear under-developed.
Seed collecting:
Collect maturing fruits by picking off the clusters that are turning yellow-orange. 
Seed cleaning:
Place the fruits in a tray and leave to dry for one to two weeks. Then rub the fruits with a rubber bung to dislodge the seeds. Use a sieve to separate the 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%.
Seeds stored:
LocationNo. of seeds
(weight grams)
of plants
Collection number
Collection location
% ViabilityStorage
BGA7800 (1.77 g)100+15-Oct-2009DJD1626
Yorke Peninsula
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.