Weed Identification

Australia > > Alkali Sida

Alkali Sida

Malvella leprosa

Alternative Name(s): Sida leprosa, Malva leprosa, Sida hederacea, Ivy-Leaf Sida

Family: Malvaceae.

Form: Herb

Origin: Native of western North America.

Flowers/Seedhead: Sepals joined at base and 510 mm long; petals 1015 mm long, yellow to cream. Flowers summer and autumn.

Description: Low growing olive-green perennial herb to 30 cm high. Stems to 50 cm long. Leaves 13cm long, 14.5 cm wide, lower surface paler, margins irregularly toothed; on stalk shorter or longer than leaf blade. Fruit with 610 fruitlets (mericarps) each containing one seed. Fruitlets about 2 mm wide, dark brown, roughened.

Distinguishing features: Distinguished by stems and leaves with small star-shaped hairs; leaves kidney-shaped with asymmetric base, 13 cm long; whorl of 3 bracts, 34 mm long attached to the jointed sepals below the flowers; petals have star-shaped hairs on the back (in Australia); fruit 56 mm wide, fruitlets with rounded apex.

Dispersal: Spreads by seeds and root fragments.

Toothed leaves with star-shaped hairs
& pale yellow flowers

Notes: Above ground growth dies in autumn and new shoots grow from the root system in spring. Infests annual crops and pastures, neglected land, and ditch banks in irrigation areas. Not readily grazed. A crop weed in California, especially on saline or alkaline soils. Has potential to expand in Australia.


    Noxious Weeds of Australia. W. Parsons and E. Cuthbertson, 1992, pages 506508. Flora of Victoria. N. Walsh and T. Entwisle (eds), 1996, Vol. 3, page 346.

Plants & roots

Crop weed in California, USA

This weed has been included in the WEEDeck field guide as card H46

More information about WEEDeck is available from Sainty & Associates Pty. Ltd.


Australia > > Alkali Sida


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