生活型

herb

形態特徵

• Annual or perennial herbs, stems 10–30 cm long, simple or branched.
• Leaves sessile, apex acute, base narrowly cuneate to semiamplexicaul, margins serrate, glabrous or lower surface sparsely glandular; emergent leaves mostly opposite, rarely 3–4-verticillate, elliptic to oblong-lanceolate, 5–35 mm long, 4–10 mm wide; submerged leaves 3–10-verticillate, oblong-lanceolate to linear-lanceolate, 10–40 mm long, 3–10 mm wide.
• Flowers solitary or in racemes, pedicels 1–15 mm long. Calyx 5–6.5 mm long, cleft to beyond middle, glandular; lobes 2.5–4 mm long; bracteoles linear, 1–1.5 mm long. Corolla tubular, white or with pinkish hue at top of tube, 8–12 mm long; lobes 2–3 mm long.
• Capsule ellipsoid, ca. 5 mm long, ca. 4 mm across.

分布

• 台灣 : in ponds, rice fields, and ditches in the north and northeast of the island (one collection in the south).
• 世界 : Japan and eastern China.

引證標本

TAIPEI: Nankan, Huang 3525; Taipei, Chuang 3048. TAOYUAN: Chungli, Sasaki s. n. 1932; Patei, Chuang 4606. KASOHSIUNG: Fengshan, Yen s. n. 1992.

參考文獻

• Liu, Ho-Yih, Flora of Taiwan, second edition 4: 601. 1998.  (Fl. Taiwan 2nd edit.)