Seeds of South Australia
Brachyscome dichromosomatica var. dichromosomatica (Compositae)
Purple Hard-head Daisy
List of species for Brachyscome
Click on an image to enlarge it
Seed collecting:
August to December
Herbarium regions:
Lake Eyre, Gairdner-Torrens, Flinders Ranges, Eyre Peninsula
NRM regions:
Eyre Peninsula, Northern and Yorke, South Australian Arid Lands
IBRA region
Olary Spur (FLB03)Flinders Lofty Block
 Data Deficient   [Edge of range]
Southern Flinders (FLB04) 
 Least Concern
Northern Flinders (FLB05) 
 Rare   (IUCN: RA d(i,ii))   [can be confused with other spp]
Central Flinders (FLB06) 
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)   [habitat degraded; grows red loamy soils]
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 Brachyscome]
Name derivation:
Brachyscome from the Greek 'brachys' meaning short and 'kome' meaning hair; referring to the short bristles or hairs of the pappus. Dichromosomatic meaning having two chromosomes.
Distribution:
Endemic to South Australia  and found in the Flinders Ranges and Lake Torrens region, growing saltbush, arid low shrubland and on rocky outcrops.
Status:
Native. Common in South Australia.
Plant description:
Annual herb to 25 cm high. Leaves basal and near-basal, not forming a rosette, pinnatisect with 5-9 linear obtuse segments, 3-8 cm long, glabrous. Yellow daisy flower appearing in June to September. Brachyscome dichromosomatica var. dichromosomatica differ from B. dichromosomatica var. alba by having pale blue or mauve ray corolla, at least on the under surface (white ray corolla in B. dichromosomatica var. alba).
Fruit type:
Dense brown daisy heads.
Seed type:
Brown black wedge-shaped seed 3 mm long and 1 mm wide, with dense long white hairs along the margin.
Embryo type:
Spatulate fully developed.
Seed collecting:
Pick heads that are maturing, drying off, with brown seeds.
Seed cleaning:
Place the seed-heads in a tray and leave to dry for a week. Then gently rub the heads 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.
Seed viability:
From one collection, the seed viability was high, at 100%.
Seed germination:
This species has physiological dormancy that need to be overcome for the seed to germinate.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA18000 (12.58 g)100+23-Nov-2010KHB530
Flinders Ranges
1-Jan-2012100%-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.
Germination table:
DateResultT0T50Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod
May 2011100%13d20d None
70mm glass petri dishes on 1% w/v agar
Incubated under winter conditions
May 2011100%13d20d None
70mm glass petri dishes on 1% w/v agar supplemented with 100mg/L Potassium Nitrate
Incubated under winter conditions
May 2011100%13d20d None
70mm glass petri dishes on 1% w/v agar supplemented with 250mg/L Gibberllic acid (pH adjusted to 6.5)
Incubated under winter conditions
May 2011100%13d13d 10 months at 40% humidity (24/0 dark/light; 15C/30C)
70mm glass petri dishes on 1% w/v agar
Incubated under winter conditions
May 201134%13dNA None
70mm glass petri dishes on 1% w/v agar supplemented with 250mg/L Gibberellic acid (pH adjusted to 6.5)
Incubated under spring/autumn conditions
May 201130%13dNA None
70mm glass petri dishes on 1% w/v agar
Incubated under spring/autumn conditions
May 201125%13dNA None
70mm glass petri dishes on 1% w/v agar supplemented with 100mg/L Potassium Nitrate
Incubated under spring/autumn conditions
Result: Maximum percentage of germination observed.
T0: Number of days before first germinant observed.
T50: Number of days to achieve 50% germination.
Pre-treatment: The initial treatment that the seeds received prior to placement on germination media.
Germination medium: The substrate that seeds were placed on for the duration of the germination experiment.
Incubator conditions:
Photoperiod: The duration of light exposure that the seeds were subject to during a 24 hour period.
Thermoperiod: The constant or diurnal temperatures that seeds were subject to during a 24 hour period.
Winter conditions: 15°C 20 h (3am→11pm); 5°C 4 h (11pm→3am) / 10 h light (8am→6pm); 14 h dark (6pm→8am)
Spring/Autumn conditions: 22°C 12 h (8am→8pm); 10°C 12 h (8pm→8am) / 12 h light (8am→8pm); 12 h dark (8pm→8am)
Summer conditions: 30°C 14 h (6am→8pm); 15°C 10 h (8pm→6am) / 14 h light (6am→8pm); 10 h dark (8pm→6am)