Acmella

Scientific name

Acmella Pers.

Common names

spotflower

Family

Asteraceae

Native distribution

New World Tropical

Species cultivated

Acmella oleracea (L.) R.K. Jansen

A. repens (Walter) Rich. Ex Pers.

Adventive distribution

introduced to Asia, Africa, Australia, Pacific Islands

Weed status

not weedy

Habit

prostrate or erect herbs

Brief description

Annual or perennial. Stem prostrate to erect. Leaves opposite, decussate; leaf blade lanceolate to ovate, sparsely hairy; apex round to acute; base round to attenuate; margin entire to toothed. Inflorescence terminal, a solitary head or a few heads in cymes; radiate or discoid. Involucre ± hemispheric; phyllaries 1-3-seriate, subequal or outer longer, entire or irregularly dentate; receptacle conical; paleate. Ray florets, when present, 2-3-lobed; pistillate; typically yellow to orange. Disk florets of 4-5 triangular, yellow or orange lobes.

Natural habitat

riparian, flood zones on river banks, pond edges, and in wet ditches

Additional comments

A genus of 30 species. The species Acmella repens (Walter) Rich. ex Pers. is semi-aquatic to aquatic, typically with floating stems; also known as Acmella oppositifolia var. repens (Walter) R.K.Jansen.