Ampelopteris prolifera (PROSEA)
Ampelopteris prolifera (Retz.) Copel.
- Protologue: Gen. fil.: 144 (1947).
- Family: Thelypteridaceae
- Chromosome number: 2n= 72
Hemionitis prolifera Retz. (1791), Goniopteris prolifera (Retz.) Presl (1836), Ampelopteris elegans Kunze (1848).
Origin and geographic distribution
A. prolifera is widely distributed in the Old World tropics, from West Africa and tropical mainland Asia to north-eastern Australia (to 30°S) and New Caledonia. It occurs throughout South-East Asia, but has not often been collected; it is absent in southern Peninsular Malaysia.
Although not often collected, young leaves of A. prolifera are eaten as a raw or cooked vegetable, especially in India, where they are considered inferior in taste to those of the more commonly eaten Diplazium esculentum (Retz.) Swartz. In traditional medicine in India, the leaves of A. prolifera are used as a laxative and in Tanzania the leaf-sap is added to a mixture which is drunk to treat meningitis and encephalitis.
A leaf extract of A. prolifera showed antiviral activity against cucumber mosaic virus.
A large, scrambling (2-4 m long), usually sterile fern with proliferous buds scattered along the leaf rachis which develop into new plants. Rhizome short-creeping, 4-10 mm in diameter. Leaves approximate, arching; proliferous buds common in the axils of the pinnae; petiole 12-50 cm long, pale brown, glabrous; lamina narrowly lanceolate to narrowly elliptical, 27-150 cm × 9-26 cm, pinnate, apex indeterminate, papery, both surfaces glabrous; leaves from plants formed by proliferation from buds much smaller, usually with pinna-like terminal lamina; pinnae numerous, the basal pairs distant, the distal ones more closely spaced and smaller, the basal 3-4 pairs gradually reducing in size; rachis with forked hairs or glabrous; midrib above with short hairs, beneath likewise veins very sparsely set with minute hairs, becoming glabrous in older leaves, midrib also bearing a few ovate or peltate, ciliate scales; buds producing long secondary leaves common in the axils of the pinnae; pinnae oblong, 10-15(-20) cm × 1.5-2 cm, sometimes fertile from a size of 3.5 cm × 0.8 cm, base truncate to subcordate, subsessile, the basal lobe often overlapping the rachis, margin crenate, often very shallowly and irregularly so, lobed to a depth of 2 mm, apex acute to acuminate, rather evenly attenuate; secondary veins numerous, 3-4 mm apart, tertiairy veins per pinna lobe up to 12 pairs, 4-7 pairs of anastomosing veins below the shallow sinus uniting alternately to form a zigzag intermediate excurrent vein. Sori circular to elongate, 4-12 on each side of the primary veins, on apical parts of the veins, without indusium, with orange capitate paraphyses,at maturity uniting with adjacent sori. Spores closely and irregularly spinulose.
Other botanical information
There is no generally accepted scientific name for this fern because specialists disagree about the delimitation of genera within the large family Thelypteridaceae. In addition to those mentioned under the synonyms, the species has also been named in the genera Cyclosorus Link, Dryopteris Adans., Meniscium Schreb., Phegopteris (Presl) Fée, Polypodium L. and Thelypteris Schmid. Sometimes the monotypic genus Ampelopteris Kunze is considered as a subgenus in the larger genera Cyclosorus or Dryopteris . A. prolifera is distinguished from other species with similar venation pattern by its adventitious leaf buds able to produce new plants (as reflected in the specific name) and its elongate sori without indusium.
A. prolifera grows mostly in full sunlight in freshwater swamps at low altitudes, usually below 300 m but occurring as high as 1000 m, or close to the edge of rivers where the rhizomes often root in the water. The proliferous stems may grow in the water. The freely proliferating buds result in effective local spread and it is significant that fertile leaves are rarely recorded (only in dry climates). It has been suggested that the plant spreads along river systems by flood waters breaking off leaves and depositing them on the river banks further downstream.
Genetic resources and breeding
Neither germplasm collections nor breeding programmes are known to exist for A. prolifera . Since it is widespread and rather common, it does not seem in danger of extinction.
The use of the leaves of A. prolifera as a vegetable would justifies research on the nutritional value and cultivation requirements. The cultivation of the fern does not seem to present big problems because the proliferous buds make vegetative propagation easy.
- Burrows, J.E., 1990. Southern African ferns and fern allies. Frandsen Publishers, Sandton, South Africa. pp. 270-272.
- Croft, J.R., 1985. Ferns and fern allies. In: Leach, G.J. & Osborne, P.L. (Editors): Fresh water plants of Papua New Guinea. University of Papua New Guinea Press, Lae, Papua New Guinea. pp. 33-74.
- Holttum, R.E., 1966. A revised flora of Malaya. 2nd Edition. Vol. 2. Ferns of Malaya. Government Printing Office, Singapore. pp. 298-299.
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- Zamora, P.M. & Co, L., 1986. Guide to Philippine flora and fauna. Vol. 2. Economic ferns, endemic ferns, gymnosperms. Natural Resources Management Center, Ministry of Natural Resources and University of the Philippines, Goodwill Bookstore, Manila, The Philippines. p. 33.
W. P. de Winter