Helminthostachys zeylanica (PROSEA)
Helminthostachys zeylanica (L.) Hook.
- Protologue: Gen. fil.: t. 47 (1840).
- Family: Ophioglossaceae
- Chromosome number: 2n= 188 (tetraploid)
Osmunda zeylanica L. (1753), Helminthostachys dulcis Kaulfuss (1824).
- Indonesia: rawu bekubang (Malay, western Sumatra), jajalakan (Sundanese), pakis kaler (Javanese)
- Malaysia: tunjok langit, akar paku, jelai
- Philippines: tungkud-langit (Tagalog)
- Thailand: kut chong (northern), tin nok yung (south-eastern, peninsular), phak nok yung (eastern)
- Vietnam: sâm dất, ráng reùng gié, sâm bòng bong.
Origin and geographic distribution
The exact origin of H. zeylanica is unknown but it is widespread at low altitudes from India, Sri Lanka, southern China and Taiwan, throughout South-East Asia to tropical Australia and the western Pacific.
H. zeylanica is used as food, medicine and as a source of fibre. In many countries, young leaves are eaten cooked as a vegetable or raw as a salad. Young petioles can be cooked, dressed and eaten as a substitute for asparagus. In Java, the rhizome is used against dysentery (fresh or powdered, said to be very effective), catarrh (some juice is sufficient) and early stages of pulmonary tuberculosis (besides eating a porridge made from the rhizome, spreading the porridge over the chest is also said to be beneficial). In the Moluccas, the rhizome is used as a mild laxative and is eaten with betel for whooping cough (it can be preserved by being candied). In Malaysia, it is regarded as a tonic and the Sakai use it to treat syphilis. In the Philippines it is used against malaria and in India for treatment of sciatica. In Java and the Philippines petioles of old leaves are used in wickerwork and handicraft. H. zeylanica can be grown as an ornamental. In Peninsular Malaysia, for some traditional medicinal applications, Syngramma alismifolia (Presl) J. Smith ( Pteridaceae , found in western Malesia, vernacular names: paku tombak, paku tunjok langit) is sometimes used as a substitute for H. zeylanica .
Production and international trade
H. zeylanica is traded only at local markets and no statistics on production or trade exist. Formerly Malaysia exported some rhizomes to China. In the Philippines it used to be sold in considerable quantities on provincial markets but plants are becoming rarer because of habitat destruction.
H. zeylanica is a good source of phosphorus, calcium and iron; per 100 g edible portion, young leaves contain approximately 1.5 g ash, of which P 350 mg, Ca 30 mg and Fe 15 mg.
Terrestrial fern with short creeping rhizome up to 7 mm in diameter, unbranched, bearing fleshy roots laterally and ventrally; erect stem part absent. Leaves in two rows, one or rarely two per growing season; petiole 10-60 cm long, fleshy, green or purplish-brown; lamina pinnate to subpalmate, 5-25 cm × 10-50 mm, tripartite, herbaceous; pinnae rhomboid to obdeltoid, up to 25 cm long, short stalked or subsessile, with a terminal lobe and one or two pairs of sessile lateral lobes; lobes lanceolate, 5-25 cm × 2-5 cm, base cuneate, decurrent, margin entire or finely and irregularly dentate, apex acuminate; veinlets all free, once or twice forked. Spike cylindrical, (3-)7-13(-21) cm × 6-7 mm, with a stalk of (3-)7-20(-30) cm, arising from the junction of the petiole and the blade, usually protruding beyond the blade, bearing numerous short branches each with a group of round sessile sporangia that open with a longitudinal slit and with small sterile lobes at the apex. Spores globose, trilete, 20-40 μm in diameter, granular with coarse, more or less fused, cylindrical projections.
Growth and development
The tuberous prothallus of H. zeylanica grows subterraneously as a saprophyte, dependent on a fungus. Anatomically it has a central strand of elongated, partially lignified cells, sometimes even a strand of true xylem. Initially the rhizome is vertical, but in older plants it changes to horizontal growth. Dormant axillary buds may be stimulated by damaging the apex of the rhizome. The adult plant usually has only 1 leaf, but sometimes up to 5; it grows with the onset of the rains and dies back to a dormant rhizome and root system over the dry season.
Other botanical information
The Ophioglossaceae is the most isolated family of the ferns and some authors consider it more closely related to a lineage of progymnosperms or cycadophytes than to typical modern ferns. Evidence from fossils to back up speculations, however, is lacking. Cladistic studies based on both morphological characters and DNA sequences suggest a position between the seed plants and the true ferns, with the whisk ferns ( Psilophyta ) as closest relatives. The morphological nature of the spike is a matter of some controversy, but now generally thought to originate from two fused fertile pinnae. Helminthostachys Kaulfuss, characterized by the radially branched spike, is represented by one species only.
H. zeylanica grows terrestrially on moist ground, along the bank of streams or on humus-rich slopes in light shade from sea-level up to 400 m altitude. In the wild it is rather difficult to find and is nowhere very common. Locally it may grow gregariously.
Propagation and planting
Propagation of H. zeylanica is by spores or by rhizome cuttings. It is not cultivated commercially.
H. zeylanica can be grown in pots with a humus-rich soil mixture. It must be kept wet while in active growth but much drier while dormant. The leaves can suffer from a leaf blight disease.
Genetic resources and breeding Since H. zeylanica is very widespread it is not in danger of extinction although habitat destruction makes it rarer in a rapidly growing number of areas. Germplasm collection and breeding programmes are not known to exist.
H. zeylanica is used on a local scale as food, medicine, and as a source of fibre in many countries in South-East Asia and elsewhere. Its many uses deserve further research on nutritional and medicinal values and on requirements for domestication.
- Campbell, D.H., 1911. The Eusporangiatae, the comparative morphology of the Ophioglossaceae and Marattiaceae. Carnegie Institution of Washington, Washington, United States. 229 pp.
- Heyne, K., 1950. De nuttige planten van Indonesië [The useful plants of Indonesia]. 3rd Edition.2 Volumes. W. van Hoeve, 's-Gravenhage, The Netherlands, Bandung, Indonesia. Vol. 1. pp. 95-96.
- Holttum, R.E., 1966. A revised flora of Malaya. 2nd Edition. Vol. 2. Ferns of Malaya. Government Printing Office, Singapore. p. 42.
- May, L.W., 1978. The economic uses and associated folklore of ferns and fern allies. Botanical Reviews 44(4): 491-528.
- Ochse, J.J. & Bakhuizen van den Brink, R.C., 1980. Vegetables of the Dutch East Indies. 3rd English edition (translation of "Indische groenten", 1931). Asher & Co., Amsterdam, The Netherlands. pp. 544-545.
- Pryer, K.M., Schneider, H., Smith, A.R., Cranfill, R., Wolf, P.G., Hunt, J.S. & Sipes, S.D., 2001. Horsetails and ferns are a monophyletic group and closest living relatives to seed plants. Nature 409: 618-622.
- Quisumbing, E., 1951. Medicinal plants of the Philippines. Technical Bulletin 16. Department of Agriculture and Natural Resources, Manila, The Philippines. p. 55.
- Shieh, W.-C. & Devol, C.E., 1994. Ophioglossaceae. In: Huang, T.-C. (General Editor): Flora of Taiwan. 2nd Edition. Vol. 1. Pteridophyta and Gymnospermae. Editorial Committee of the Flora of Taiwan, Taipei, Taiwan. pp. 63-73.
- Tagawa, M. & Iwatsuki, K., 1979. Helminthostachys. In: 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. 38-39.
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