Seeds of South Australia
Senecio longicollaris (Compositae)
Riverina Fireweed
List of species for Senecio
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Seed collecting:
November to April
Herbarium regions:
Murray, Southern Lofty
NRM regions:
Adelaide and Mount Lofty Ranges, South Australian Murray-Darling Basin
IBRA region
Murray Mallee (MDD02)Murray Darling Depression
 Near Threatened   [no records, recently named; in Census; fluctuating abundance; restricted to river]
Murray Lakes and Coorong (MDD03) 
 Rare   (IUCN: RA d(ii))   [fluctuates along boundary of lakes]
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 Senecio]
Name derivation:
Senecio from the Latin 'senex' meaning an old man, referring to the white pappus attached to the seed. Longicollaris from the Latin 'longus' meaning long and 'collaris' meaning of the neck, referring to the long-necked achenes.
Distribution:
Found along the Murray River and Lake Alexandrina in South Australia, growing in floodplains and edge of rivers. Also found in Queensland, New South Wales and Victoria.
Status:
Native. Very rare in South Australia. Very rare in the other states.
Plant description:
Erect herb to 1.8 m high with fleshy roods. Leaves in middle third of stems evenly spaced and sized, very narrow elliptic, 8–24 cm long, denticulate, upper surface sparsely appressed-cottony, glabrescent, lower surface green, with sparse to moderate coarse hairs. Inflorescence corymbose with 30–100 yellow rayless daisy flower. Flowers throughout the year but mostly between September and February.
Fruit type:
Large fluffy daisy-head with exposed white pappus. Achenes 4–6 mm long, brown; pappus 6–7 mm long.
Seed type:
Brown cylindrical seed to 6 mm long and 0.4 mm wide, dilated at one end and tapering to a slender neck at the other, with scattered hairs along the ridges and long pappus.
Embryo type:
Spatulate fully developed.
Seed collecting:
Collect heads that are large and fluffy. Either pick off the whole heads or use your finger and pull off the seeds from the head. Mature seeds will come off easily.
Seed cleaning:
Place the heads in a tray for a week to dry. No cleaning is required if only pure seeds are collected. If heads are collected, then rub the heads gently with your hands to dislodge the seeds. Viable seeds will be fat and hard. 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 average to high, ranging from 79% to 92%.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA3600 (0.7 g)2020-Nov-2007RJB76150
Murray
19-Sep-200890%-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-1290%8 d8 d
1% agar with 100 mg/L potassium nitrate;
Incubated under winter conditions
Jun-1290%8 d8 d
1% agar with 250 mg/L gibberellic acid (pH 6.5);
Incubated under winter conditions
Jun-1284%8 d8 d
1% agar;
Incubated under spring/autumn conditions
Jun-1282%8 d8 d
1% agar with 250 mg/L gibberellic acid (pH 6.5);
Incubated under spring/autumn conditions
Jun-1282%8 d8 d
1% agar;
Incubated under winter conditions
Jun-1278%8 d8 d
1% agar with 100 mg/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)