刺果狐尾藻 ci guo hu wei zao

Myriophyllum spathulatum Blatter & Hallberg.

Plants monoecious. Stem much branched, to 150 cm. Submerged leaves 4- or 5-whorled, pectinate, ovate in outline, 2.5-4.0 × 1.0-1.5 cm; segments in 8-25 pairs, filiform, 1-2 cm; emergent, uppermost leaves alternate, spatulate to linear, 5-20 mm, margin shortly lobed to entire. Inflorescence of axillary flowers on emergent part of stem; bracts and bracteoles inconspicuous, ovate, margin entire. Flowers 4-merous. Sepals ovate, ca. 0.5 mm, margin finely serrate to entire. Petals white, broadly spatulate, 0.5-1.5 mm, persistent in fruit. Fruit 4-loculed, 4-angled, 2-3.5 mm; mericarps abaxially acute, spinose-verrucose, apices not spreading. Fl. and fr. May-Sep.

Stagnant and shallow waters; 100-400 m. Guangdong [India, Malaysia; Australia].