生活型

herb

形態特徵

• Annual glabrous herbs, stems erect or ascending, up to 30 cm tall, simple or branched near the base.
• Leaves petiolate, ovate, lanceolate to obovate, oblanceolate, 8–30 mm long, 3–12 mm wide, palmately 3–5-nerved, apex acute to obtuse, base attenuate to cuneate, margin crenate or serrate; petiole 1–3 mm long.
• Flowers solitary, axillary; the upper ones in more or less terminal leafy racemes; cleistogamous flowers present; pedicel shorter than subtending leaves, 2–20 mm long. Calyx cleft nearly to base, 2.5–4.5 mm long; lobes linear, puberulent. Corolla blue or very pale purple, 4–8 mm long. Stamens 4; anterior pair staminodes, linear, apex clavate; posterior pair fertile, included.
• Capsule narrowly ovoid to ellipsoid, subequaling or slightly longer than the persistent calyx, 4–6 mm long.

分布

• 台灣 : naturalized in water margins in the north.
• 世界 : Native to North America.

引證標本

TAOYUAN: Puhsin, Chaw et al. 747.

參考文獻

• LIU, Ho-Yih, Flora of Taiwan, second edition 4: 605. 1998.  (Fl. Taiwan 2nd edit.)