水蕨 shui jue

Acrostichum thalictroides Linnaeus, Sp. Pl. 2: 1070. 1753; A. siliquosum Linnaeus; Ceratopteris siliquosa (Linnaeus) Copeland; Ellobocarpus oleraceus Kaulfuss; Furcaria thalictroides (Linnaeus) Desvaux; Pteris siliquosa (Linnaeus) P. Beauvois; P. thalictroides (Linnaeus) Swartz (1800), not Muhlenberg (1793); Teleozoma thalictroides (Linnaeus) R. Brown ex H. Richards.

Plants green, 5-70 cm tall, juicy and soft. Rhizome erect, short. Fronds clustered and dimorphic. Sterile fronds: stipe green, semicylindrical, 3-30 cm, ca. 1 cm in diam. or less, fleshy, not expanded, sparsely scaly; lamina erect or floating when young, ovate to lanceolate, 6-30 × 3-15 cm, base rounded-cuneate, apex acuminate, 2-4-pinnate; pinnae 5-8 pairs, alternate; lower 1 or 2 pairs larger, ovate to oblong, up to 10(-35) × 7 cm, base subrounded to subtruncate, apex acute to acuminate, 1-3-pinnate; pinnules 2-5 pairs, alternate, stalk short and with narrow wings on both sides, blade broadly ovate or ovate-triangular, up to 4 × 3 cm, deeply divided, base rounded-truncate, apex obtuse to acuminate; ultimate lobe linear-oblong or linear-lanceolate, up to 2 × 0.5 cm, entire, base decurrent along rachis forming broad wing, apex obtuse to acute; upper pair of pinnae similar in shape to basal pair of pinnae but gradually smaller. Fertile fronds: stipe same as in sterile fronds; lamina oblong or ovate-triangular, 15-40 × 10-22 cm, base rounded-cuneate or rounded-truncate, 2- or 3-pinnate, apex acuminate; pinna 3-8 pairs, alternate, lower 1 or 2 pairs of pinnae larger, ovate or narrowly triangular, up to 14 × 6 cm, stalked; ultimate lobe linear to siliquiform, 1-4 × ca. 0.2 cm, margin thin, strongly reflexed toward costa, like false indusium, apex acuminate. Veins anastomosing. Lamina softly herbaceous, green when young and brownish when old, glabrous; rachis and costa same color as stipe, smooth. Sporangia attached to veinlets on both sides of main vein, covered with reflexed margin of lobe, brown, with 30-70 annulus cells, with 32 spores inside. Spores tetrahedral, more than 100 μm in diam., with granular perine and thick exospore forming rich parallel ridges on surface. 2n = 154, 156 (tetraploid).

Ponds, ditches, rice fields, taro patches, usually rooting. Anhui, Fujian, Guangdong, Guangxi, Guizhou (Liping), Hainan, Hubei, Jiangsu, Jiangxi, Shandong, Sichuan, Taiwan, Yunnan, Zhejiang [India, Indonesia, Japan, Malaysia, Myanmar, Nepal, New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; Africa, Australia, Central, North, and South America, Madagascar, Pacific islands, West Indies].