Malastrum from the genus Malva and the Latin 'aster' meaning like, but implying incomplete likeness or inferior. Americanum means of or from the Americas; referring to the species natural distribution in the warmer parts of the Americas.
Distribution and status
Found in the northern part of South Australia, growing around waterholes, bores, swamps and clay pans, floodouts, riparian vegetation and in disturbed areas. Also found in Western Australia, Northern Territory, Queensland and New South Wales. Introduced. Common in South Australia. Common in the other states.
Herbarium regions: North Western, Lake Eyre, Nullarbor, Gairdner-Torrens, Flinders Ranges, Eastern, Eyre Peninsula, Northern Lofty
NRM regions: Alinytjara Wilurara, Eyre Peninsula, Northern and Yorke, South Australian Arid Lands
AVH map: SA distribution map (external link)
Erect, annual or short-lived perennial herb to 50 cm tall covered in stellate hairs. Leaves alternate ovate to broadly ovate, to 7 cm long and 6 cm wide. Inflorescence a dense terminal spike to 4.5 cm long with yellow to orange flowers. Flowering throughout the year. Fruits are brown depressed-globular capsule on a long spike, each with 9 seed segments. Seed embryo type is folded.
Seed collection and propagation
Collect seeds between January and December. Collect capsules that are drying off and starting to turn brown and seeds inside should be brown and hard. Collect either individual mature capsule or break-off the whole spike. Place the capsules into a tray and leave to dry for a week. Then rub the capsules by hand or 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. This species has physical dormancy that needs to be overcome for the seed to germinate (e.g. nicking or softening the seed coat).