Onychium siliculosum (PROSEA)
Onychium siliculosum (Desv.) C. Chr.
- Protologue: Index filic.: 468 (1906).
- Family: Pteridaceae
- Chromosome number: 2n= 58
Pteris siliculosa Desv. (1811), Onychium auratum Kaulf. (1824), O. tenue Christ (1901).
- Philippines: pakong-anuang, dila-dila, buhok-virgin (Tagalog)
- Laos: ko kout pha.
Origin and geographic distribution
O. siliculosum is distributed from India, the Himalayas, Burma (Myanmar), Thailand, Indo-China to south-western China (Yunan), Taiwan, the Philippines, Java and New Guinea to Polynesia.
In the Philippines, juice from the crushed leaves of O. siliculosum is said to be a good preventive for baldness. A decoction of the leaves is used as a remedy for dysentery in the Philippines although from other areas it has been recorded as having laxative properties. O. siliculosum is also used as an ornamental.
Production and international trade
There is no international trade or commercial cultivation of O. siliculosum . It is collected from the wild for home use only.
O. siliculosum contains onitin, a phenolic illidoid sesquiterpene, and a farinaceous exudate from stalked glands occurs prominently on the undersurface of the leaves.
A terrestrial fern, up to about 1 m tall. Rhizome short, ascending or creeping, densely covered with scales; scales linear, subulate, 5-7 mm long, thin but firm, entire, concolorous brown, spreading. Leaves 3-4-pinnate at the base, dimorphous; petiole stout, 10-46 cm long, stramineous to pale brown, glabrous but scaly at base; sterile lamina oblong-ovate to lanceolate deltoid, up to 48 cm × 7-20 cm, round at base, acuminate at apex, herbaceous, glabrous on both sides but with stalked glands at underside, green to yellow-green; rachis glabrous, adaxially sulcate; pinnae gradually reducing in size, the basal ones oblong-subdeltoid, up to 8 cm × 20 cm, petiolate, caudately acuminate at apex; pinnules and secondary pinnules distinctly petiolate; ultimate segments spatulate, oblique, sometimes slightly falcate, 5-10 mm × 1-2.5 mm, the base cuneate, margins with a few narrow, acute, entire lobes, acute at apex; fertile lamina with the segments pod-like and larger, 5-25 mm × 1-2.5 mm, the terminal ones longer making the pinnae caudate. Sori covering the abaxial side, completely protected by reflexed marginal flaps, densely coated with golden-yellow wax. Spores tetrahedral-globose, 30 μm × 35 μm, with a prominent equatorial flange and coarse adjacent ridges.
Growth and development
The gametophyte of O. siliculosum is initially spatulate with a lateral meristem, later developing lobes with additional meristems. Old gametophytes are asymmetrically cordate or irregularly lobed with archegonia and antheridia variously distributed.
Other botanical information
Onychium Kaulf. is currently classified in the subfamily Taenitidoideae of the Pteridaceae and comprises about 8 species distributed in the Old World tropics. In taxonomic literature it has variously been classified, e.g. in Parkeriaceae and Polypodiaceae . O. japonicum (Thunb.) Kunze, occurring from the Philippines and Java north to Korea at much higher altitudes than O. siliculosum , does not have yellow wax on the fertile segments and has brown sori; it also has a shorter petiole, more clustered leaves, longer ultimate pinnules and marginal attachment of the indusia. It has antimicrobial activity. A putative carcinogen, ptaquiloside, was detected in an unidentified Onychium species.
O. siliculosum is found on exposed steep sites, such as fairly dry banks of new roads in open locations, around 600 m altitude near the equator but at 800-1000 m further north.
Propagation and planting
Propagation of O. siliculosum is by spores.
Genetic resources and breeding
No germplasm collections or breeding programmes for O. siliculosum are known to exist. It is widely distributed and does not seem to be in danger of genetic erosion but germplasm collection is recommended.
Little is known about the possibly bioactive constituents of O. siliculosum and further research is needed to evaluate its potential.
- Khan, Z. & Shaheen, S., 1998. A study of antimicrobial activity of a few ferns of Pakistan. Journal of Animal and Plant Sciences (Pakistan) 8: 7-12.
- Quisumbing, E., 1951. Medicinal plants of the Philippines. Technical Bulletin 16. Department of Agriculture and Natural Resources, Manila, The Philippines.pp. 67-68.
- 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. 194-196.
- 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. 60.
Dedy Darnaedi &Titien Ngatinem Praptosuwiryo