Category: Ceratopteridaceae

Ceratopteris sp.: No images seen now.
An exclusively aquatic fern. taken at Lalbagh,Oct 22

Ceratopteris thallictroides

That is very clearly a superb clump of Ceratopteris pteridioides. In the past they have often all been put as one species in India, “C. thalictroides“, but in fact three species and two subspecies occur there – C. thalictroides is a tetraploid species with a thinner stipe and not so huge (it is not just a matter of growth!), but C. pteridoides is commoner in the plains and has the very characteristic thick, succulent stipe so well shown in your photo. C. pteridoides is diploid (though I can’t quite see the chromosomes this time!!).
They make a nice sag – especially the more foliose C. pteridioides. [sorry I have to check exactly how it is spelt correctly – but my book is in London and I’m currently in Edinburgh!], check it on www.ipni.org

Actually it isn’t really thalictroides – only in a very broad sense if one recognises only one species. But a check of Lloyd’s monograph and the fine new work by Masuyama in Japan reveals more to it than that. This particular photo is very characteristic of pteridioides.

… comment has made the topic interesting. He has refered to work of Masuyama of Japan. I furnish below some of the differences between the two species pointed out by Masuyama. I think it is worth comparing the plant with the characteristics pointed out here.

CERATOPTERIS Brongniart, Bull. Sci. Soc. Philom. Paris, sér. 3, 8: 186. 1821[1822 per ING].

水蕨属shui jue shu

Lin Youxing (林尤兴); Shigeo Masuyama

Parkeria Hooker.

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, dimorphic; stipe green, ± expanded, semicylindrical, fleshy, smooth, with sparse scales, with many longitudinal ridges on surface and many small vascular bundles inside. Sterile lamina green, ovate- to lanceolate-triangular, thinly herbaceous, simple or pinnate; ultimate lobe broadly lanceolate or loriform, entire, acute at apex; veins anastomosing; gemma occasionally formed in axil of pinnae, brownish, small, ovate, 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, green when young and brownish when old, linear to siliquiform; 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. x = 13(39).

Four to seven species: tropics and subtropics; two species in China.

In China, the rhizomes and fronds are used medicinally for treating fetal toxins and phlegm buildup. The young fronds are used as a vegetable.

1a. Plants rooting in silt; sterile frond varied in form, pinnate to 3-pinnate, tall or short depending on environment; stipe 3–30 cm, ca. 1 cm in diam., base unexpanded; fertile fronds taller than sterile ones, lamina oblong or ovate-triangular ……………………………………………………… 1. C. thalictroides

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

1. Ceratopteris thalictroides (Linnaeus) Brongniart, Bull. Sci. Soc. Philom. Paris, sér. 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 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 granulate 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 [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].

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 toward base, base of stipe narrowly cuneate, covered with roots. Fronds dimorphic. Sterile fronds green, smooth; stipe semicylindrical, 5–8 cm, ca. 1.5 cm in diam.; lamina ovate-triangular, simple and deeply divided, sometimes opposite-pinnate; lobes triangular to broadly loriform. Fertile fronds green when young and brownish when old, smooth; stipe 5–8 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, Jiangxi, Shandong [Bangladesh, India, Vietnam; Central, North, and South America]