Pogostemon

Scientific name

Pogostemon Desf.

Common names

eusteralis, Australian hygrophila

Family

Lamiaceae

Could be confused with

Gratiola, Limnophila, Mentha

Native distribution

tropical regions of Asia and Australia

Species commonly cultivated

Pogostemon helferi (Hook. f.) Press (Thailand)

P. stellatus (Lour.) Kuntze (Asia to Australia)

P. yatabeanus (Makino) Murata (Japan)

Adventive distribution

none

Weed status

not weedy

Habit

emergent, attached stem plant

Brief description

Annual or perennial. Stem erect, ascending, with creeping stolon, adventive roots produced from basal nodes. Leaves in whorls of 4 to 10, evenly spaced along stem, but densely packed at apex when submersed, sessile; leaf blade linear to lanceolate, midvein prominent; margin entire to finely serrate. Inflorescence an apical (sometimes axillary) spike of densely arranged, small flowers. Flowers zygomorphic, bisexual; sepals 5; corolla of 4 subequal lobes, pink to purple; stamens 4. Dispersal by seed or stem fragments.

Natural habitat

Swamps, rivers, lakes, and floodplains.

Additional comments

Pogostemon consists of approximately 75 species and is distributed throughout tropical Asia and Australia. Dysophylla and Eusteralis are considered synonyms of Pogostemon. Only two species are presently cultivated for aquariums and ponds. In the submersed form, P. stellatus has numerous geographical varieties, but has narrower leaves than P. yatabeanus, and often has red foliage.