Cyclosorus heterocarpus (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Cyclosorus heterocarpus (Blume) Ching

Protologue: Bull. Fan Mem. Inst. Biol., Bot. 8(4): 180 (1938).

Family: Thelypteridaceae

Chromosome number: 2n= 72

Synonyms

Aspidium heterocarpon Blume (1828), Dryopteris heterocarpa (Blume) O. Kuntze (1891), Thelypteris heterocarpa (Blume) Morton (1959), Sphaerostephanos heterocarpus (Blume) Holttum (1974).

Origin and geographic distribution

C. heterocarpus is found from southern China throughout South-East Asia to northern Australia and Polynesia.

Uses

The leaf of C. heterocarpus is rubbed on the skin for treatment of leucoderma in Malaysia. C. heterocarpus is also used as an ornamental.

Production and international trade

C. heterocarpus is collected from the wild or locally grown in gardens. No international trade exists and it is not commercially cultivated.

Properties

No information is available about chemical compounds of C. heterocarpus . In other thelypterioid ferns (e.g. in some other Cyclosorus species) cytotoxic and antibacterial constituents have been demonstrated.

Description

A pinnate, hairy, terrestrial fern with the pinnae suddenly reduced on the petiole. Caudex erect, usually branched near the base; scales narrow, up to 8 mm × 1.2 mm, dark brown, hairy. Leaves tufted, pinnate-pinnatifid; petiole 50-80 cm long until the basal real pinnae, bearing auricles (reduced pinnae) down to little more than 5 cm from the base, shortly hirsute, scaly at the base; auricles 6-10 pairs, the distal ones 1-2 cm long, with a few lobes and a linear apical part, the lower ones decreasing in size, with short aerophores; lamina oblong-lanceolate, 60-120 cm × 20-40 cm, the basal pinnae suddenly dwarfed to mere auricles, the apex acute, dark green to yellowish-green, thinly papyraceous, pubescent adaxially, the hairs appressed, 0.3-0.4 mm long, sometimes with a few glands, copiously glandular abaxially with yellow glands and a few hairs; rachis, costa and veins hairy throughout, with 1 mm long, antrorse pale hairs abaxially; pinnae linear to linear-lanceolate, ascending, up to 10-20 cm × 1.2-2.5 cm, the fertile ones sometimes narrower, sessile with broadly cuneate to subtruncate base, the apex caudate-acuminate, lobed to over half-way to the costa, the apex-margin entire, basal pinnae narrowed at their bases; ultimate divisions oblong, oblique, subfalcate, up to 4 mm wide, rounded to obtuse; basal veins anastomosing in at least the basal part of the pinna, with excurrent veins to the sinus, the second acroscopic vein sometimes touching the membrane at the sinus. Sori round, medial, 6-9 on a side, dark; indusia firm, persistent, brown at maturity, with a few short hairs and glands; sporangia with glands near the annulus. Spores monolete, spinulous, black.

Other botanical information

C. heterocarpus has long been known as Sphaerostephanos heterocarpus . The Thelypteridaceae is a large family with many related species which often are difficult to tell apart, even for specialists. Holttum grouped the Old World species into 25 genera (including Sphaerostephanos J. Smith), which however are often difficult to separate without a microscope. Therefore, at present a more conservative classification is maintained, distinguishing 5 genera in which Sphaerostephanos is merged as a subgenus (176 species) into the large genus Cyclosorus Link (comprising 20 subgenera with in total more than 1000 species). It may be assumed that many uses are not limited to a single species. C. heterocarpus is a very variable species in which numerous varieties and forms have been distinguished that are often not sharply distinct.

Ecology

C. heterocarpus grows in shady locations in the lowlands and up to 1500 m altitude in the mountains, usually near streams or trails and at the fringe of the forest. In the mountains it tends to grow larger.

Propagation and planting

C. heterocarpus can be propagated by spores. Propagation by separating branched rhizomes seems possible as well but is not really known.

Husbandry

If planted, C. heterocarpus needs shade, humus and a well-drained soil.

Genetic resources and breeding

C. heterocarpus is quite common in a large area and it does not seem to be in danger of genetic erosion. No germplasm collections or breeding programmes are known to exist.

Prospects

Too little is known of C. heterocarpus to predict its future. Since some useful compounds have already been found in various members of the Thelypteridaceae , further investigation could be revealing.

Literature

• Bidin, A., 1989. Tinjauan flora dan sitotaksonomi paku pakis di Semenanjung Malaysia [A review on the flora and cytotaxonomy of ferns of Peninsular Malaysia]. Penyelidikan Semasa Sains Hayat 4: 47-58.
• Holttum, R.E., 1966. A revised flora of Malaya. 2nd Edition. Vol. 2. Ferns of Malaya. Government Printing Office, Singapore. pp. 269-271.
• Holttum, R.E., 1981. Thelypteridaceae. Flora Malesiana, Series 2. Pteridophyta (Ferns & fern allies). Vol. 1, part 5. M. Nijhoff / W. Junk Publishers, The Hague, The Netherlands. pp. 457-458.
• Smith, A.R., 1990. Thelypteridaceae. In: Kramer, K.U. & Green, P.S. (Volume editors): Pteridophytes and gymnosperms. In: Kubitzki, K. (Series editor): The families and genera of vascular plants. Vol. 1. Springer-Verlag, Berlin, Germany. pp. 267-272.
• Tagawa, M. & Iwatsuki, K. (Volume editors), 1979-1989. Pteridophytes. In: Smitinand, T., Larsen, K. (Series editors): Flora of Thailand. Vol. 3. Forest Herbarium, Royal Forest Department, Bangkok, Thailand. pp. 416-417.

Authors

Dedy Darnaedi & W.P. de Winter