Hygroryza

Scientific name

Hygroryza Nees

Common names

none

Family

Poaceae

Could be confused with

unlikely to be confused with any other aquatic plant

Native distribution

India, Sri Lanka, Pakistan, China

Species commonly cultivated

Hygroryza aristata (Retz.) Nees (Southeast Asia)

Adventive distribution

Thailand, Indonesia, Bangladesh

Weed status

significant weed species in rice in Southeast Asia

Habit

floating, branching grass with inflated leaf sheaths

Brief description

Perennial grass. Stoloniferous, culms creeping or ascending, floating, with roots produced at internodes. Leaves floating or emergent; leaf blade entire, ovate to ovate-oblong, olive green, venation parallel with distinct pale midvein; leaf sheath inflated with aerenchyma. Inflorescence a panicle; spikelets single flowered. Floret with long awn. Dispersal by stem fragments and seeds.

Natural habitat

still waters of lakes, ponds, canals, and flooded rice fields

Additional comments

Hygroryza aristata, the sole species in the genus, is one of the few grasses that is regularly cultivated for aquaria or ponds. Hygroryza has inflated leaf sheaths to aid in flotation and can form dense, floating mats.