Seeds of South Australia
Centipeda nidiformis (Compositae)
Cotton Sneezeweed
List of species for Centipeda
Click on an image to enlarge it
Seed collecting:
March to July
Herbarium regions:
Lake Eyre, Murray, South Eastern
NRM regions:
South Australian Arid Lands, South Australian Murray-Darling Basin, South East
IBRA regions
Lucindale (NCP03)Naracoorte Coastal Plain
 Data Deficient   [lack of records]
Murray Mallee (MDD02)Murray Darling Depression
 Near Threatened   (Probable Decline)   [restricted to river; flood dependent]
Wimmera (MDD05) 
 Data Deficient   [lack of records]
Murray Scroll Belt (RIV06)Riverina
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)   [flood dependent]
Sturt Stony Desert (CHC02)Channel Country
 Near Threatened   [restricted to flood plains; common during good season]
Coongie (CHC06) 
 Near Threatened   [restricted to flood plains; common during good season]
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 Centipeda]
Name derivation:
Centipeda from Latin for centipede, from 'centi' meaning hundred and 'ped' meaning foot; referring to the creeping stems. Nidiformis meaning nest-shaped; referring to the depressed-hemispherical flower receptacle.
Distribution:
Found in three disjunct locations in South Australia in Innamincka, along the Murray River and in the upper South-east, growing along the margins of watercourses on clay or clay-loam soils. Also found in all mainland states.
Status:
Native. Uncommon in South Australia. Uncommon in Western Australia, New South Wales and Victoria. Common in the other states.
Plant description:
Decumbent to ascending cottony annual, spreading to 15 cm diameter and to 15 cm high, adventitious roots not or rarely produced. Branches densely white-cottony at least on young growth. Leaves more or less spathulate, to 10 mm long and 5 mm wide, usually with very slender petiole-like bases that are often almost as long as (occasionally longer than) the broader part of the lamina, shallowly toothed or subentire, surfaces light to densely cottony, with scattered resin droplets. Flower heads yellow with no petal, globular when fully open to 5 mm diam, solitary. Flowering between January and April.
Fruit type:
Dense brown daisy head.
Seed type:
Pale brown four-angle pyrimidal seed  to 1.2 mm long and 0.4 mm wide, with scattered hairs on the narrower part.
Embryo type:
Spatulate.
Seed collecting:
Collect heads that are drying off and turning brown.
Seed cleaning:
Place the heads in a tray for a week to dry. Then rub the heads gently with your hands or a rubber bung to dislodge the seeds. Use a sieve to separate the unwanted material. Be careful as the seeds are very small. 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 average, at 50%.
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
BGA41300 (1.44 g)2017-May-2007RJB71826
North Western
19-Sep-200850%-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
October 201576%7d7d Soak in 500mg/L gibberellic acid for 48 hrs
1% water agar
Incubated under spring/autumn conditions
October 201568%7d7d soak in 500 mg/L gibberellic acid for 48 hrs
1% water agar
Incubated under winter conditions
October 201554%7d14d None
1% water agar
Incubated under spring/autumn conditions
October 201540%7dNA None
1% water 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)