箭叶雨久花 jian ye yu jiu hua

Pontederia hastata Linnaeus, Sp. Pl. 1: 288. 1753; Monochoria dilatata (Buchanan-Hamilton) Kunth; M. hastifolia C. Presl, nom. illeg. (included P. hastata); M. sagittata (Roxburgh) Kunth; P. dilatata Buchanan-Hamilton; P. sagittata Roxburgh.

Herbs perennial, aquatic. Vegetative stems often long and robust. Radical leaves with sheath broadened at base; petiole 30--90 cm; leaf blade triangular or triangular-ovate, 5--15(--25) × 3--15 cm, base sagittate to hastate, apex acute to acuminate. Flowering stems erect or obliquely so, 50--90 cm; leaf petiole 7--10 cm. Inflorescences erect or suberect, remaining so after anthesis, subumbellate to shortly racemose, 10--40-flowered; peduncle distinctly shorter than associated leaf petiole. Pedicels 1--3 cm. Perianth segments bluish with green median vein and reddish blotch, ovate, 1--1.6 cm. Larger stamen: anther 5.3--6.5 mm. Smaller stamens: filaments filiform; anthers 3--4 mm. Style densely and shortly spreading hairy at apex. Capsule oblong, ca. 1 cm. Seeds brown, oblong; wings ca. 10. Fl. Aug, fr. Mar.

Pools, rice fields, ditches; 100--700 m. Guangdong, Guizhou, Hainan, Yunnan [Bhutan, Cambodia, India, Indonesia, Malaysia, Myanmar, Nepal, Sri Lanka, Vietnam].