Botanical art
Prior names
Oedera trinervia
Flaveria australasica
Common names
Clustered Yellow-tops
Speedy Weed
Yellow Twin-stem
Etymology
Flaveria from the Latin 'flavus' meaning yellow; referring to a yellow dye made from a Chilean species. Trinervia from the Latin 'tri' meaning three and 'nervum' meaning nerve; referring to the leaves with 3-veins.
Distribution and status
Found in the north-east part of South Australia, growing in many types of wet habitats on saline and alkaline soils and highly disturbed areas. Also found in Western Australia, Northern Territory, Queensland and New South Wales. Naturalised. Common in South Australia. Common in the other states.
Herbarium regions: Lake Eyre, Gairdner-Torrens, Flinders Ranges, Eastern
AVH map: SA distribution map (external link)
Plant description
Much-branched erect or procumbent annual herb to 75 cm tall with opposite branches often pinkish-red, mostly hairless. Leaves opposite, yellowish-green, narrowly elliptic to oblanceolate, to 75 mm long, 3-veined from the base, narrowing at the base into a pseudo-petiole, margin more or less finely toothed. Flower heads numerous in congested axillary and terminal heads, yellow with very short ray-florets. Flowers throughout the year. Fruits are creamy-brown papery head. Seeds are black long ovoid seed to 3 mm long and 0.8 mm wide, with a number of striations Seed embryo type is spatulate fully developed.
Seed collection and propagation
Collect seeds between January and December. Collect heads that are matured, drying off and turning pale brown with hard black seeds. Place the heads in a tray for one to two week to dry. Then rub the heads gently with your hands to dislodge the seeds. Use a sieve to separate any 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. From one collection, the seed viability was high, at 95%. Seeds are non-dormant, viable seed should germinate readily.
Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
---|---|---|---|---|---|---|---|
BGA | 22,000 (8.78 g) | 30+ | 22-Aug-2010 | MJT297 Lake Eyre | 1-Jan-2012 | 95% | -18°C |