Seeds of South Australia
Olax obcordata (Olacaceae)
Sweetheart Leaves
List of species for Olax
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Seed collecting:
December to January
Herbarium regions:
Eyre Peninsula, Kangaroo Island
NRM regions:
Eyre Peninsula, Kangaroo Island
IBRA regions
Kangaroo Island (KAN01)Kanmantoo
 Endangered   (IUCN: EN B2ab(i,ii,v))   (Probable Decline)   [~ 1,000 plants; long lived; only found at Cape Borda, 2 pops.]
Eyre Hills (EYB03)Eyre Yorke Block
 Endangered   (IUCN: EN B2ab(i,ii,iii); D)   (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 Olax]
Name derivation:
Olax from the medieval Latin 'olax' meaning ill-smelling; referring to the wood of some Asiatic species which have an unpleasant odour. Obcordata means inverse heart shape; referring to the shape of the leaf.
Distribution:
Endemic to South Australia and found on the western side of Kangaroo Island and three old records in the lower Eyre Peninsula, growing on calcrete.
Status:
Native. Rare in South Australia. Presumed extinct on Eyre Peninsula.
Plant description:
A semi-parasitic perennial shrub to 1.2 m high with round, fleshy, yellow-green, inverted heart-shaped leaves and bronze stems. Flowers are white at the axis of the leaves, appearing in spring.
Fruit type:
Green, ovoid fruit to 7 mm long, with a persistent stalk.
Seed type:
Round, pale yellow, woody seeds to 4 mm long.
Seed collecting:
Thorough searching is required to locate the fruits as they are usually hidden between the leaves. Collect the fruits that are large and hard.
Seed cleaning:
No cleaning is required. 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 average, at 70%.
Seed germination:
This species is generally difficult to germinate, it has morphophysiological dormancy and complex germination requirements.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA320 (6.72 g)DJD13801-Jan-2012-18°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.