Seeds of South Australia
Pycnosorus pleiocephalus (Compositae)
Soft Billy-buttons
List of species for Pycnosorus
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Seed collecting:
September to December
Herbarium regions:
North Western, Lake Eyre, Nullarbor, Gairdner-Torrens, Flinders Ranges, Eastern, Eyre Peninsula
NRM regions:
Alinytjara Wilurara, Eyre Peninsula, South Australian Arid Lands
IBRA regions
SUMMARY
Olary Spur (FLB03)Flinders Lofty Block
 Least Concern
Southern Flinders (FLB04) 
 Least Concern
Northern Flinders (FLB05) 
 Least Concern
Central Flinders (FLB06) 
 Least Concern
Eyre Mallee (EYB05)Eyre Yorke Block
 Rare   (IUCN: RA d(ii))
South Olary Plain (MDD01)Murray Darling Depression
 Near Threatened   [northern spp ]
Murray Mallee (MDD02) 
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)
Braemer (MDD07) 
 Least Concern
Murray Scroll Belt (RIV06)Riverina
 Near Threatened   (Probable Decline)
Myall Plains (GAW01)Gawler
 Least Concern
Gawler Volcanics (GAW02) 
 Least Concern
Gawler Lakes (GAW03) 
 Least Concern
Arcoona Plateau (GAW04) 
 Least Concern
Kingoonya (GAW05) 
 Least Concern
Torrens (GAW06) 
 Least Concern
Roxby (GAW07) 
 Least Concern
Commonwealth Hill (GAW08) 
 Least Concern
Maralinga (GVD03)Great Victoria Desert
 Least Concern
Yellabinna (GVD06) 
 Least Concern
Nullarbor Plain (NUL02)Nullarbor
 Least Concern
Yalata (NUL03) 
 Least Concern
Barrier Range (BHC01)Broken Hill Complex
 Least Concern
Barrier Range Outwash (BHC04) 
 Least Concern
Bimbowrie (BHC05) 
 Least Concern
Curnamona (BHC06) 
 Least Concern
Dieri (SSD03)Simpson Strzelecki Dunefields
 Least Concern
Warriner (SSD04) 
 Least Concern
Strzelecki Desert (SSD05) 
 Least Concern
Breakaways (STP01)Stony Plains
 Least Concern
Oodnadatta (STP02) 
 Least Concern
Murnpeowie (STP03) 
 Least Concern
Witjira (STP06) 
 Least Concern
Baltana (STP07) 
 Least Concern
Sturt Stony Desert (CHC02)Channel Country
 Least Concern
Diamantina-Eyre (CHC04) 
 Least Concern
Coongie (CHC06) 
 Least Concern
Mann-Musgrave Block (CER01)Central Ranges
 Near Threatened
Everard Block (CER03) 
 Near Threatened
IBRA regions
DISPLAY ALL
4 of 6 subregionsFlinders Lofty BlockLeast Concern
Eyre Mallee (EYB05)Eyre Yorke BlockRare
  (IUCN: RA d(ii))
3 of 6 subregionsMurray Darling DepressionLeast Concern
, Near Threatened
, Rare
Murray Scroll Belt (RIV06)RiverinaNear Threatened
  (Probable Decline)
8 of 8 subregionsGawlerLeast Concern
2 of 4 subregionsGreat Victoria DesertLeast Concern
2 of 3 subregionsNullarborLeast Concern
4 of 4 subregionsBroken Hill ComplexLeast Concern
3 of 4 subregionsSimpson Strzelecki DunefieldsLeast Concern
5 of 7 subregionsStony PlainsLeast Concern
3 of 4 subregionsChannel CountryLeast Concern
2 of 3 subregionsCentral RangesNear Threatened
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.
Distribution:
Found across the northern part of South Australia, growing in wet sandy or clayey depressions but also on stony ridges in mallee and chenopod shrubland. Also found in all mainland states.
Status:
Native. Common in South Australia. Rare in Western Australia, Northern Territory and Queensland. Common in New South Wales and Victoria.
Plant description:
Erect or ascending annual herb with many stems to 40 cm high. Leaves oblanceolate to 70 mm long and 10 mm wide, acute to obtuse, surfaces olive-brown to green, with glandular and flattened hairs. Inflorescence a single ovoid or globose compound lemon-yellow heads to 20 mm long and 15 mm wide. Flowering between August and November, but probably dependent on time of rainfall.
Fruit type:
Dense pale ovoid to globular heads with numerous seeds.
Seed type:
Brown ovoid seed to 2 mm long and 1 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 one collection, the seed viability was low, at 45%.
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
23400 (22.49 g)
23400 (22.49 g)
100+3-Nov-2005DJD176
Eyre Peninsula
14-Sep-200645%-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.