PARKERIACEAE [Draft]

水蕨科  hui jue ke

Lin You-xin (林尤興); Shigeo Masuyama

Ferns, annual, juicy, aquatic. Rhizome erect, short, with thick roots, dictyostele, with scales at apex; scales broadly ovate or cordate to peltate, entire, thin, brownish hyaline. Fronds clustered; stipe green, ฑ expanded, semicylindrical, fleshy, smooth, with sparse scales, with many longitudinal ridges on surface and many small vascular bundles inside. Fronds dimorphic. Sterile lamina green, ovate- to lanceolate-triangular, thinly herbaceous, simple or pinnate; ultimate lobe broadly lanceolate or loriform, entire, acute at apex; veins anastomosing; occasionally gemma formed in axil of pinnae, small, ovate, brownish, resulting in juveniles through asexual propagation. Fertile lamina similar in morphology to sterile lamina, but normally taller, divided more deeply and finely; ultimate lobe reflexed toward costa to enclose sori, linear to siliquiform, green when young and brownish when old; rachis green, with longitudinal ridges, deplanate when dry. Sori attached along costa, narrowly linear, covered with reflexed margin of lobe. Sporangium large, subsessile; annulus broad, vertical, consisting of 0–70 incrassate cells; trilete[??] mark obvious or not. Spores 16 or 32 per sporangium, large, tetrahedral, trilete, with fine, parallel ridgelike ornamentations.

One genus of four to seven species: worldwide tropics and subtropics; two species in China.

1. CERATOPTERIS Brongniart, Bull. Sci. Soc. Philom. Paris, s้r. 3, 8: 186. 1821.

水蕨属  shui jue shu

Parkeria Hooker.

Characters same as the family. x = 13(39).

About four to seven species worldwide; two species in China.

In China, the rhizomes and fronds are used as medicine for fetal toxins[??toxicity] and accumulation of phlegm. The young fronds are used as a vegetable.

1a.     Plant rooting in silt; sterile frond varied in morphology, pinnate to 3-pinnate, tall or short depending upon aquatic habitat condition; stipe 3–30 cm, below 1 cm in diam., base unexpanded; fertile frond taller than sterile one, ovate to lanceolate to oblong ....................................................................  1. C. thalictroides

1b.     Plant usually floating; sterile frond simple to pinnatifid to pinnate, broadly triangular; stipe 5–8 cm, 1–3 cm in diam., base much expanded; fertile frond not taller than sterile one, broadly triangular  2. C. pteridoides

1. Ceratopteris thalictroides (Linnaeus) Brongniart, Bull. Sci. Soc. Philom. Paris, s้r. 3, 8: 186. 1821.

水蕨  shui jue

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

Plants green, 70 cm tall, juicy and soft. Rhizome erect, short. Fronds clustered and dimorphic. Sterile stipe green, semicylindrical, 3–30 cm, below 1 cm in diam., fleshy, not expanded, glabrous, with sparse scales; lamina erect or floating when young, ovate to lanceolate, 6–30 ื 3–15 cm, base rounded-cuneate, 2–4-pinnate, apex acuminate; pinnae 5–8 pairs, alternate; lower 1 or 2 pairs larger, ovate to oblong, up to 10(–35) ื 7 cm, base subrounded to subtruncate, 1–3-pinnate, apex acute to acuminate; pinnules 2–5 pairs, alternate, broadly ovate or ovate-triangular, up to 4 ื 3 cm, base rounded-truncate, stalk short and with narrow wings on both sides, deeply divided, apex obtuse to acuminate; ultimate lobe linear-oblong or linear-lanceolate, up to 2 ื 0.5 cm, base decurrent along rachis forming broad wing, entire, apex obtuse to acute; upper pair of pinnae similar in shape with basal pair of pinnae, but gradually smaller. Fertile stipe same as sterile one; 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 soft 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. Spore tetrahedral, more than 100 μm in diam., with glanulate perine and thick exine forming rich parallel ridges on surface. 2n = 154, 156; tetraploid.

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

2. Ceratopteris pteridoides (Hooker) Hieronymus, Bot. Jahrb. Syst. 34: 561. 1905, [‘pteroides’].

粗梗水蕨  cu geng shui jue

Parkeria pteridoides Hooker, Exot. Fl. 2: t. 147. 1825; Ceratopteris parkeria J. Smith

Plants usually floating, 20–30 cm tall. Stipe, rachis, and costa of lower pinnae all obviously expanded in lower parts, base of stipe long cuneate, covered with roots. Fronds dimorphic. Sterile fronds simple and deeply divided, sometimes opposite-pinnate, green, smooth; stipe semicylindrical, 8 cm, ca. 1.5 cm in diam.; lamina ovate-triangular, lobe triangular to broadly loriform. Fertile fronds green when young and brownish when old, smooth; stipe 8 cm, 1–3 cm in diam.; lamina broadly triangular, 15–25 cm, 2–4-pinnate; ultimate lobe linear or siliquiform, 2–6 ca. 0.2 cm, margin thin, strongly reflexed toward main vein to cover sori, apex acuminate. Sporangia attached to veinlets on both sides of main vein, covered with reflexed margin of lobe, brown, with 0–40 annulus cells, with 32 spores inside. Spore tetrahedral, below  100 μm in diam., with few parallel ridges. 2n = 78; diploid.

Marshes, ponds, ditches, usually floating on water. Anhui, Hubei, Jiangsu, [??add Jiangxi], Shandong [Bangladesh, India, Vietnam; North America (including C America and West Indies), South America].