Hygroryza aristata

(Retz.) Nees
Common names: Asian watergrass Water stargrass
Treatment appears in FNA Volume 24. Treatment on page 46.
Please click on the illustration for a higher resolution version.
Illustrator: Sandy Long

Copyright: Utah State University

Culms 50-150 cm, floating, branched, flexuous; nodes rooting, roots feathery, whorled. Sheaths glabrous, open, inflated; ligules absent or 0.5-0.8 mm, hyaline, truncate; pseudopetioles shorter than 1 mm; blades 2-8 cm long, 5-20 mm wide, flat, bases rounded to cordate, apices blunt to rounded. Panicles 3-8 cm, pyramidal, with 4-9 branches; lower branches 2-4 cm, whorled, spreading or deflexed, glabrous; pedicels 0.2-2 mm, sometimes absent. Florets (6)7-18 mm (including the stipelike callus), narrowly lanceolate; calluses (1)2-10 mm, stipelike; lemmas 5-8 mm, chartaceous, keeled, veins and margins with hairs, glabrous or pubescent between the veins, awns 5-14 mm; paleas as long as the lemmas, chartaceous, glabrous, keels ciliate or scabrous; anthers 6, about 3.5 mm. Caryopses about 3.5 mm. 2n = 24.

Discussion

Hygroryza aristata is native to tropical Asia, where it has occasionally been used as forage for cattle (Bor 1960). It is sold for ponds and aquaria, where its long, feathery, adventitious roots have a decorative effect, but it has the potential to become a significant weed problem in the southern United States.

Selected References

None.

Lower Taxa

None.