Blechnum orientale

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Blechnum orientale


Asia-Temperate, Asia-Tropical: India present; Sri Lanka (Sri Lanka present), Burma present, Japan present, Nepal present, SE Asia present, northern Australia present, tropical Pacific Islands mostly north of the tropic of Capricorn to longitude 135° E present
Malesia: Throughout. Outside Malesia: Most abundant and widely distributed species of the genus, extending westwards from longitude 70° E and south of latitude 30° N through SE Asia, northern Australia, and eastwards through the tropical Pacific Islands mostly north of the tropic of Capricorn to longitude 135° E. The species ranges from Nepal through India, Burma and Sri Lanka to China and Japan.


Roy & Singh (), Khare (), and Mahabale & Kamble () reported for Indian material n = 32; Singh & Roy () for Sikkim plants also reported n = 32. Tsai & Shieh () for Taiwan material reported n = 33, and for Indian material Vasudeva & Bir () and Manickam & Raj (Cytology of ferns of the western Ghats (South India) today & tomorrow (1988)) also reported n = 33. Ghatak () for Indian material reported n = 34. M. Tindale (pers. comm.) has 2n = c. 64-66 for Australian collections.


“Blechnum orientale L. is used together with Elephantopus scaber [an abundant tropical weed in the Compositae] for dropsy. The fern is believed to entice out the ‘centipede’ [or worm or snake] which has lodged in the liver” (). A recent paper by Christensen (Holttum Mem Vol. (1997)) records the vernacular names pao abu for the Kelabit and kelindang for the Iban people; both groups use the species for medicine and as a vegetable. The Kelabit in Nanga Sumpa pound young fronds and use the resulting paste to treat blisters and abscesses; in Pa Dalih a decoction is made from the young fronds and drunk to treat mouth ulcers. Also in Nanga Sumpa, B. orientale is mixed with hot spices and other vegetables and eaten raw as ulam.


1. The extreme phenotypic plasticity of B. orientale not only allows it to tolerate an exceptionally wide range of habitats but also to have spore bearing plants which range from less than 20 cm in height to over 300 cm and this partly accounts for the extensive list of synonyms.
2. Some variation may be genotypic, understanding of which would require transplant experiments and molecular studies. The growth form varies from small leathery fertile plants on dry exposed soil banks to large harsh ferns of open spaces on the margins of lowland and sometimes upland tropical and subtropical forests.
3. The fronds of the young plants from about the 5-leaf stage resemble scaled-down mature sterile plants and the basal auricles are already present on the rhachis. Under some conditions the plants may become fertile even at this early stage. The pinnae of the earliest fronds are adnate and the apices obtuse while those on slightly older plants are acute.
4. Herbarium specimens from large mature plants can be easily confused with those of B. finlaysonianum, but the young plants of B. orientale are readily identified as they are scaled-down versions of the mature plants whereas those of B. finlaysonianum are very distinctive (see description under that species). Mature plants of the two species are less likely to be confused in the field as B. finlaysonianum is essentially a shade fern of forest habitats with pinnae up to 4 cm wide that usually do not taper significantly until the apex, which narrows suddenly to become acuminate or even attenuate then tapers into what appears to be a drip tip. Pinnae of B. orientale are usually less than 2 cm wide and taper evenly from the mid-region to an acute apex. The sori of B. finlaysonianum are consistently narrower than those of B. orientale. The separation of B. finlaysonianum and B. orientale is normally not difficult. Holttum (1954) points out a number of useful characters for separating these species.
5. Occasional mutant populations of B. orientale have been recorded with almost bipinnate fronds. We have not recognised these as separate taxa. At K, Burbidge s.n., 1877-1878, Lantahan, Sabah, is a very large frond with each pinna in the mid-region equivalent to a whole small normal frond with auricles at its base. This matches var. pinnatum Bonap. (), the type of which comes from “Annam, 1500 m, Dr Sallet s.n.”. Molesworth Allen () illustrates a fine bipinnate form from Girdle Hill, Fraser’s Hill, 4200 ft, which she also reports from Batu Lintang Road in Kuching, Sarawak, at sea level.
6. This species was incorrectly listed as ‘America meridionali’ in . Linnaeus (1753) referred B. orientale to a specimen from ‘America meridionalis’ and the other, B. occidentale, to a specimen ‘Habitat in China, Osbeck’, a situation he corrected in 1763. The naming of these two taxa has generally been accepted as an error, a view confirmed by Christensen ().
7. Another specimen at G (Morton photo 16837) which is part of Roxburgh Herbarium was not selected as lectotype as the name is not in Roxburgh’s hand, see Morton (), Prince of Wales Island, Moluccas.


A.G.Piggott & C.J.Piggott 1988: Ferns of Malaysia in colour: 400: pl. 1226-1231
S.B.Andrews 1990: Ferns Queensland: 94: f. 7.4B
Hook. 1859: Fil. Exot.: pl. 77
Holttum 1954: p. 446. – In: Revis. Fl. Malaya: f. 259b, 260a, 262a-d
P.M.Zamora & Co 1986: Fl. & Fauna Philipp: 51: f. 43
T.C.Chambers & P.A.Farrant 2001 – In: Blumea: 324