Terrestrial or ruperstral ferns, sometimes growing along swamps or marshes; rhizome erect to long-creeping, dictyostelic, bearing scales. Fronds mostly long-stipitate, the stipe with 2 vascular strands at the base uniting upwards to form one of U-shape. Fronds mostly pinnate with crenate to pinnatifid pinnae, uncommonly simple or bipinnate, glabrous or with various hairs or glands, venation in each pinna of pinnate groups about a costule in each lobe, free, terminating at the margin or just short of it, often the basal veins of each group uniting to form a single excurrent vein that terminate in the sinus membrane. Sori borne on the adaxial surface of the veins, round or sometimes slightly elongate, with a +/- reniform indusium or not; sporangia often bearing hair or glands; annulus longitudinal, interrupted; spores nearly always monolete.
A predominantly tropical family of c. 30 genera (or much less depending on the author) encompassing more than 1000 species. In Papuasia there are 17 genera in the narrow sense, with more than 220 species; mostly terrestrial, only three of these genera are aquatic.
Croft, J.R. 1985. Ferns and Fern Allies, in Leach, G.J. & Osborne, P.L. 1985. Freshwater Plants of Papua New Guinea. 33 - 74, f. 6 - 13, pl. 5 - 7.
Holttum, R.E. 1971b. Studies in the family Thelypteridaceae III. A new system of genera in the old world. Blumea 19: 17 - 52, f. 1 - 19.
Holttum, R.E. 1977. The family Thelypteridaceae in the Pacific and Australasia. Allertonia 1: 169 - 243, f. 1 - 10.
Holttum, R.E. 1982. Thelypteridaceae. Fl. Males. ser. 21: 331 - 560, f. 1 - 20.
Holttum, R.E., Sen, U. & Mittra, D. 1970. Studies in the family Thelypteridaceae II. A compartive study of the type-species of Thelypteris Schmidel, Cyclosorus Link, and Ampelopteris Kunze. Blumea 18: 195 - 215, f. 1 - 112.
Notes: The genera of Thelypteridaceae are considered in the narrow sense of Holttum (1971b, 1977, 1982 etc.). Other authors take a wider view assigning most species to larger Cyclosorus and Thelypteris; in the extreme view most species have been combined into a vast Thelypteris.
|1||Large scrambling fern with proliferous buds scattered along the rachis developing into new fronds and plants; nearly all veins of a group uniting with adjacent groups to form a single excurrent vein...||Ampelopteris|
|Ferns of moderate size, lacking proliferous buds; veins of each group free to the margin or only the basal pair uniting at the base of the marginal tooth…||...2|
|2||Basal pair of veins uniting with adjacent pairs; large spherical glands present at the ends of the hairs on sporangium stalks...||Cyclosorus|
|All veins free to the margin; such glands lacking...||Thelypteris|
Large terrestrial or subaquatic ferns in swampy areas. Sterile fronds often of apparently indefinite apical growth, fertile fronds with a terminal pinna, both bearing proliferating buds along the rachis from which roots and one or several new fronds may develop, the rhizome creeping, radially symmetric, dictyostelic, bearing broad-based, subpeltate scales with unicellular, superficial or marginal, glandular or acidular hairs. Fronds long-stipate, 2 vascular bundles at the base of the stipe uniting upwards to form a single U-shaped vascular strand, the lamina pinnate, basal pinnae not reduced, midrib of pinnae grooved above, but the groove not confluent with the rachis groove, pinnae crenulate or subentire, simple or branched unicellular hairs borne on upper surface of costae; veins in a pinnate group for each crenulation, nearly all anastomosing with the adjacent group to form a straight excurrent vein terminating in the sinus, few veins of each group free to margin. Sori exindusiate, slightly elongate on the distal parts of the veins; sporangia on a 2-seriate stalk bearing glandular hairs, protected by multicellular glandular paraphyses, annulus longitudinal, interrupted, of 14 - 19 thickened cells. Spores monolete, plae, with a folded, densely spinulose perispore.
Represented in Papuasia by a single species:
Fronds to 3 m or more long, with 1 - several new fronds often developing from the axillary bulbils, stipe c. half the length of the frond, basal pinnae only slightly reduced, largest pinnae to c. 20 x 2 cm, mostly 10 - 15 x 1.5 - 2 cm, base truncate, asymmetric, often stalked 1mm, apex gradually narrowed, acute, margin crenulate-serrate to a depth of 1 - 2 mm, glabrous on both surfaces; costules 3 -4 mm apart, bearing 8 - 12 pairs of lateral veins, most of which unite with the adjacent group to form a single zig-zag excurrent vein terminating in the sinus. Sori exindusiate, in two rows between the costules, up to 10 pairs between the midrib and the margin, closer to the excurrent vein than to the costules.
Habitat: Freshwater swamps at low altitudes, mostly below 300 m altitude, but occuring as high as 1000 m, or beside rivers, at the water edge, the rhizome often rooted in the water, the proliferous stems growing into the water and often rooting there; mostly in full sun.
Distribution: Widely scattered from West Africa, through tropical mainland Asia, the Philippines and Indonesia to Papuasia, NE Australia and New Caledonia. Infrequently collected thoughout its range, in Papuasia it has been collected from swamps in Irian Jaya, The Sepik, Morobe, Western and Central provinces.
Notes: Holttum (1981) notes that the fronds on plants produced from the proliferating buds are much smaller with the apex more pinna-like; the pinnae may be fertile as small as 8 x 35 mm.
Medium to large terrestrial ferns, often in swamps or beside lakes. Rhizome slender, long-creeping, with scattered tufts of roots, dichotomous or monopodial, radially symmetric, dictyostelic, bearing thin, ovate, non-peltate scales with marginal and superficial, acicular or glandular, unicellular hairs. Fronds long stipate, the stipe with 2 vascular bundles at the base uniting upwards to form a single U-shaped strand, lamina pinnate with pinnately shallow-lobed pinnae, the basal pinnae not reduced, midrib of pinnae grooved above, but the groove not confluent with rachis groove, lower surface of costae with small, thin, flat scales, upper surface always with very fine unicellular acicular hairs, spherical orange glands on abaxial surface of lamina and veins; veins in a pinnategroup in each pinna lobe, the basal veins only anastomosing to form an excurrent vein terminating in the sinue (the next acroscopic vein may unite with the excurrent vein and the next basiscopic vein may join it at the sinus), the remainder oblique, free, simple, terminating at the margin. Sori round, indusiate, medial on each vein, the indusium reniform, with unicellular, acicular and glandular hairs on the margin and outer surface; sporangia on a 2-seriate stalk with a long uniseriate seta or uniseriate glandular hair, protected by multicellular glandular paraphyses, the annulus longitudinal, interrupted, of 14 - 18 thickened cells. Spores monolete, densely spinulose and bacculate.
A pantropic genus or probably three species, represented in Papuasia by a single species:
Fronds to c. 1 m long, including stipe to 50 cm long, the stipe dark at the base, reddish upwards, largest pinnae 8 - 15 x 1 - 1.8 cm, the basal pair slightly reduced, apex gradually tapering, base rounded to more or less tapering, margin serrate-crenate, lobed less than half-way to the midrib, costules 3.5 - 4.5 mm apart, bearing 6 - 10 (or more) pairs of veins the basal pair (sometimes 2 pair) uniting to form a single excurrent vein terminating in the sinus, the next pair of veins touching the sides of the sinue membrane; lower surface of the veins, costules etc., and sometimes the lamina, with a variable number of pale acicular hairs, such hairs also present on the upper surface of the rachis and midribs. Sori with a thin indusium, distal on the veins and absent from the basal pairs, often appearing restricted to the lobes of the pinnae.
Habitat: Edges of swamps and swamp-grassland transitions, from sea level to 1500 m altitude, but mostly at low altitudes below 50 m, rhizome often fully submerged, in full sun. Twice on floating mats of vegetation in swamps or deep open marshes. Once mixed with Sphaerostephanos unitus and once with Christella arida (see note below). Sometimes is drier situations. Locally common.
Distribution: A pantropic lowland species. In Papuasia scattered in the lowland areas of the New Guinea mainland from Irian Jaya to Milne Bay. Not often collected but to be expected elsewhere in swampy areas.
Notes: (See note under Thelypteris confluens). This species was widely known as Cyclosorus gongylodes (Schkuhr) Link, based on Aspidium gongylodes Schkur from Guiana, a plant considered by Holttum (1977, 1981) to be tetraploid. Cyclosorus interruptus is based on an earlier name.
This species is often confused with several other genera of Thelypteridaceae of generally weedy aspect that grow in the open sun. Holttum (1977) provided a key to separate the species of the tropical lowlands, and it seems profitable to reproduce part of it here to avoid confusion, especially as Cyclosorus interruptus has been found in mixed collections with some of these species:
|1||Basal pinnae never more than slightly smaller than those next above them; thin flat scales present on the lower surface of the costae and pinnae...||Cyclosorus interruptus|
|Several pairs of basal pinnae gradually or abruptly smaller, no flat scales on costae...||... 2|
|2||At the base frond a very abrupt transition to very small pinnae, several much less than 1 cm long; glands on lower surface small, spherical...||Sphaerostephanos unitus|
|At the base of the frond several pairs of pinnae gradually reduced, the lowest at least 1 cm long; glands on lower surface, if present, elongate...||... 3|
|3||Thick glandular hair present on the lower surface; (sporangia lacking hairs near annulus)...||Christella arida|
|No glands on the lower surface; (sporangia bearing short acicular hairs near the annulus)...||Sphaerostephanos invisus|
The last two species are very difficult to separate on macroscopic characters.
Terrestrial ferns of moderate size, often in swamps and near lakes. Rhizome slender, short- to long-creeping, irregularly branched, radially symmetric, dictyostelic, bearing brown, ovate, non-peltate scales, with marginal and superficial, acicular or glandular, unicellular hairs. Fronds long stipate, the stipes with 2 vascular bundles at the base uniting upwards to form a single U-shaped vascular strand; lamina pinnate with lobed pinnae, the basal pinnae not reduced, midrib of pinnae grooved about but the groove not confluent with rachis groove, surface with unicellular, acicular or glandular hairs, lower surface of costae with small thin flat scales with entire margins; veins in a pinnate group in each pinn-lobe, the veinlets free, forked, terminating in the margin. Sori round, indusiateon the acroscopic branch of each vein, the indusium reniform with glandular hairs on the margin and outer surface; sporangia on a 2-seriate stalk bearing muticellular glandular hairs, unicellular glands present either side of the annulus, the annulus longitudinal, interrupted, of 14 - 18 thickened cells. Spores monolete, spinose, spinulose and bacculate.
A genus of 2 species, one northern hemisphere the other southern hemisphere, represented in Papuasia by a single species:
Rhizome thin and wiry, c. 2 mm diameter, dark, stipe stramineus, dark at the base. Fronds to 1 mm long (in New Guinea 30 - 40 cm long) including stipe half the length of the frond, pinnae 20 -25 x 4 - 5 mm (outside New Guinea to 50 x 10mm), fertile pinnae more contracted than sterile, the basal pair c. half size, deeply lobed to less than 1 mm from costa, the basal pair of lobes longer than the others, gradually tapering towards the tip, lower surface of midrib with thin flat orbicular scales, and a variable number of short hairs; sterile pinnae with 1 - several pairs of forked veins, the veins mostly simple in fertile pinnae. Sori indusiate, near the costules.
Habitat: At middle to high altitudes, 1700 - 2500 m, in swampy open ground near lakes, water-logged peat, Sphagnum bogs, in wet depressions, in full sun. May be locally common.
Distribution: Africa and Madagascar, southern India, Thailand, Sumatra, the New Guinea mainland and the north island of New Zealand. In New Guinea infrequently collected in the highland areas from Irian Jaya to the Central province. Like many swamp plants, perhaps more common than collections indicate.
Notes: The genus Thelypteris is considered here in the narrow sense. In the broadest sense it has been made to include all the genera in the Thelypteridaceae.
This species is the temperate (or in Papuasia, 'montane') equivalent of Cyclosorus interruptus, occupying the same niche in cooler climates.