Plants of
South Australia
Hydrocotyle diantha
Umbelliferae
Kangaroo Island Pennywort
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Vulnerable
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Adelaide
Arkaroola
Ceduna
Coober Pedy
Hawker
Innamincka
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Oodnadatta
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Keith
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Etymology

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.

Distribution and status

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.
Herbarium regions: Yorke Peninsula, Kangaroo Island
NRM regions: Kangaroo Island, Northern and Yorke
AVH map: SA distribution map (external link)

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. Fruits are yellow-orange cluster of tiny fruits each with two seed segments. Seeds are orange wedge-shaped seed to 1.5 mm long and 1 mm wide, with 3 slender ribs and a wing along the outer edge. Seed embryo type is linear under-developed.

Seed collection and propagation

Collect seeds between October and December. Collect maturing fruits by picking off the clusters that are turning yellow-orange. 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. From one collection, the seed viability was high, at 85%.

Seeds stored:
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LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA7,800 (1.77 g)100+15-Oct-2009DJD1626
Yorke Peninsula
1-Jun-201085%+5°C, -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.