Seeds of South Australia
Sigesbeckia orientalis (Compositae)
Indian Weed
List of species for Sigesbeckia
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Seed collecting:
January to December
Herbarium regions:
Lake Eyre, Eyre Peninsula, Southern Lofty, Kangaroo Island, South Eastern
NRM regions:
Adelaide and Mount Lofty Ranges, Eyre Peninsula, Kangaroo Island, South Australian Arid Lands, South East
IBRA regions
Mount Gambier (SVP02)Southern Volcanic Plain
 Rare   (IUCN: RA d(ii))   [one old record; found at the bluff]
Glenelg Plain (NCP02)Naracoorte Coastal Plain
 Rare   (IUCN: RA d(i,ii))   [(no records) found in Honans- T Horn, B Haywood]
Fleurieu (KAN02)Kanmantoo
 Near Threatened   (Probable Increase)   [undercollected; likes wet disturbed areas, esp creeks]
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Near Threatened   (Probable Increase)   [undercollected; likes wet disturbed areas, esp creeks]
Olary Spur (FLB03) 
 Data Deficient   [Undercollected]
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 Sigesbeckia]
Name derivation:
Sigesbeckia named after Johann Georg Siegesbeck (1686-1755), a German physician, botanist, director of the Botanical Gardens at St Petersburg and pronounced opponent of the Linian system, who named this small-flowered, unpleasant-smelling, grows in mud, weedy genus after him following their bitter rivalry. Orientalis from the Latin 'orientale' meaning eastern or of or from the Orient; alluding to the species distribution across Asia and Austrolasia.
Distribution:
Found in the southern Mount Lofty Ranges and the lower South-east in South Australia, growing in seasonally moist sites in dryish vegetation. Also found in Queensland, New South Wales and Victoria (and Indian sub-continent, south-eastern Asia, Papua New Guinea). Introduced in Western Australia and Tasmania.
Status:
Native. Uncommon in South Australia. Common in the other states.
Plant description:
Erect herb to 80 cm high with slightly pubescent, brown stems. Leaves lanceolate to spear-shaped, to 15 cm long and 7 cm wide, in remote pairs, petiolate, pubescent, with glandular hairs, veins prominent, margins irregularly dentate or sinuate-toothed. Inflorescence in dense clusters (capitula) of sessile yellow flowers to 10 mm diameter with outer involucral bracts irregular, spreading, narrow-spathulate, to 11 mm long, densely covered with dark stalked glands. Flowers throughout the year.
Fruit type:
Green-black round fruit with numerous seeds in terminal clusters.
Seed type:
Blackish slightly angled seed to 3 mm long and 1.2 mm wide, slightly striated surface with few tubercules.
Seed collecting:
Collect fruit that are maturing, turning yellow and fat with hard seeds.
Seed cleaning:
Place the fruit in a tray and leave to dry for 1-2 weeks or until it begin to split. Then rub the dried fruit 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%.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
3250 (3.85 g)
3250 (3.85 g)
30-4029-Mar-2006DJD443
Southern Lofty
14-Sep-200685%-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.