Seeds of South Australia
Pimelea williamsonii (Thymelaeaceae)
Williamson's Riceflower
List of species for Pimelea
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Seed collecting:
November to December
Herbarium regions:
Eyre Peninsula, Murray
NRM regions:
Eyre Peninsula, South Australian Murray-Darling Basin
IBRA regions
Eyre Hills (EYB03)Eyre Yorke Block
 Vulnerable   (IUCN: VU D1+2)
Talia (EYB04) 
 Vulnerable   (IUCN: VU B2ab(i,ii,iii))   (Probable Decline)
Eyre Mallee (EYB05) 
 Rare   (IUCN: RA d(ii))
Murray Mallee (MDD02)Murray Darling Depression
 Vulnerable   (IUCN: VU D2)   [needs fire or disturbance]
Lowan Mallee (MDD04) 
 Rare   (IUCN: RA d(i,ii))   [highly localised]
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 Pimelea]
Name derivation:
Greek 'pimele' fat, alluding to the fleshy cotyledons and
Distribution:
Sandy soils and disturbed sites, often observed post-fire
Status:
Rare
Plant description:
Wooly subshrub to 30cm tall. Leaves elliptic, 2.5-16 mm long, 1-5 mm wide, acute to obtuse, lower surface with coarse antrorse white or colourless hairs and the upper surface with fewer and finer hairs. Inflorescence a terminal spike to 6.5cm long.  Flowers bisexual, white, 3.5-5 mm long. Flowering most of the year.
Seed type:
Seed ventricose, hooked at the apex, glabrous, black, finely reticulate 1-5mm
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
2100 (1.18 g)
2100 (1.18 g)
50+16-Nov-2010DEM7055
South Eastern
1-Jan-201295%-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
Jun-0823%20 dNA after ripening 45°C oven 6weeks;
1% agar;
Incubated under winter conditions
Jun-0813%27 dNA
1% agar;
Incubated under winter conditions
Jul-118%28 dNA
1% agar with 250 mg/L gibberellic acid (pH 6.5);
Incubated under winter conditions
Jul-112%56 dNA
1% agar with 100 mg/L potassium nitrate;
Incubated under winter conditions
Jul-112%28 dNA
1% agar with 250 mg/L gibberellic acid (pH 6.5);
Incubated under spring/autumn conditions
Jul-110%NANA
1% agar with 100 mg/L potassium nitrate;
Incubated under spring/autumn conditions
Jul-110%NANA
1% agar;
Incubated under spring/autumn conditions
Jul-110%NANA
1% agar;
Incubated under winter 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)