Gamochaeta americanum (ASTERACEAE) Cudweed

Weeds to Whack

Annual or short-lived perennial herb to 25 cm. Prefers damp, shady positions. Native to Central and South America. Forms a ring of leaves (basal rosette) then branched leafy stems. Leaves are white or silvery on the underside. The basal leaves are larger and sessile, while upper leaves have petioles. Flowers are whitish brown, in spikes at the tips of the branches. Seeds have a ring of hairs at one end. Wandering cudweed Gamochaeta pensylvanica has a similar habit and flowers, but its leaves are distinctly different. They are slightly whitish woolly on both surfaces, whereas the leaves of Gamochaeta americanum are glossy-green on top and densely white woolly underneath. Jersey Cudweed Pseudognaphalium luteoalbum has thinner, grey-green leaves that do not continue all the way up to the flower heads.

Photo: Robert Whyte