狐尾藻 hu wei zao

Myriophyllum limosum Hectot ex Candolle.

Plants mostly monoecious, rarely with bisexual flowers. Perennation by clavate turions. Stem robustly branched or unbranched, 50-150 cm; internodes often shorter than leaves. Submerged leaves 4-6-whorled, pectinate, narrowly ovate in outline, 3-5 × 1.5-2.5 cm; segments in 10-20 pairs, filiform, 1-2.5 cm. Inflorescence a terminal spike of 4-whorled flowers, 7-20 cm; bracts pectinate or absent. Male flowers: bracteoles lanceolate-lobed; calyx broadly campanulate, ca. 1 mm, 4-parted nearly 1/2 of way to base; petals white or greenish, obovate, 2-2.5 mm; stamens 8. Female flowers: bracteoles pectinate, 1-5 × as long as flower; calyx tubular, shortly lobed; petals greenish or white, minute. Fruit 4-loculed, subglobose, ca. 3 mm; mericarps smooth or sparsely verrucose along margins. Fl. and fr. Apr-Sep.

Stagnant waters, lakes, ditches, slow streams, occasionally drying ponds; near sea level to 3500 m. Throughout China [Africa, Asia, Europe, North America].

In its terrestrial form this species may fully develop as small plants, with few leaf segments, and often set fruit better than the aquatic form.