Seeds of South Australia
Pycnosorus chrysanthes (Compositae)
Golden Billy-buttons
List of species for Pycnosorus
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Seed collecting:
November to February
Herbarium region:
South Eastern
NRM region:
South East
IBRA region
Lowan Mallee (MDD04)Murray Darling Depression
 Endangered   (IUCN: EN D)   [strict habitat requirements; in roadsides/railway reserves]
Wimmera (MDD05) 
 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 Pycnosorus]
Name derivation:
Pycnosorus from the Greek 'pyknos' meaning dense or thick and 'soros' meaning heap, referring to the dense flowering heads of the genus. Chrysanthes from the Greek 'chrysos' meaning golden and 'anthos' meaning flower.
Distribution:
Found in the South-east in South Australia, growing moist areas in woodland, scrub and grassland on heavy soils. Also found in Queensland, New South Wales and Victoria.
Status:
Native. Very rare in South Australia. Common in the other states.
Plant description:
Erect or ascending annual or short-lived herb with many unbranched, densely white woolly stems to 60 cm high. Leaves linear to linear-lanceolate to 10 cm long and 7 mm wide, acute, gland-tipped, upper surface olive-green to brown, glabrescent, lower surface often paler, white-woolly particularly on midrib and margins. Inflorescence a single ovoid or globose compound golden-yellow heads to 15 mm diameter. Flowering between September and December.
Fruit type:
Dense pale ovoid to globular heads with numerous seeds.
Seed type:
Brown ovoid seed to 1.5 mm long and 0.8 mm wide, covered in long white hairs.
Embryo type:
Spatulate fully developed.
Seed collecting:
Collect heads that are drying off, fluffy and turning yellow-white with hard brown seeds. Pick off whole heads or pluck off mature seeds with your fingers.
Seed cleaning:
Place the heads in a tray and leave to dry for one to two weeks. Then rub the heads gently by hand 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 four collections, the seed viability were low to high, ranging from 45% to 100%. This may reflect the level of seed cleaning undertaken.
Seed germination:
Seeds are non-dormant, viable seed should germinate readily.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
25678+26287 (44.68+45.74 g)
49000 (92 g)
19718-Jan-2005DJD 91
South Eastern
31-Mar-200695%+5°C, -18°C
BGA8100 (5.69 g)13-Feb-2006DJD485
South Eastern
14-Sep-200645%+5°C, -18°C
BGA12500 (7.8 g)60+19-Dec-2007KHB100
South Eastern
19-Sep-200890%+5°C, -18°C
BGA41000 (12.71 g)100+19-Dec-2007KHB101
South Eastern
19-Sep-2008100%+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.