Odontosoria chinensis (PROSEA)
Odontosoria chinensis (L.) J. Smith
- Protologue: In: Seeman, B.C.: Bot. Voy. Herald: 430 (1857).
- Family: Dennstaedtiaceae
- Chromosome number: 2n= 188, about 200, 290-294 (tetraploid, hexaploid)
- Sphenomeris chinensis (L.) Maxon (1913),
- S. chusana (L.) Copel. (1929),
- Stenoloma chusana (L.) Ching (1933).
- Chinese lace fern (En)
- Indonesia: paku jamuju, paku camara (Java).
Origin and geographic distribution
O. chinensis is widespread in the tropical and subtropical parts of the Old World from Madagascar (but not in continental Africa), throughout South-East Asia to Polynesia and Hawaii and northwards to Japan and Korea.
O. chinensis is mentioned as a medicinal and an ornamental plant in the Philippines. Fresh or dried plant parts are used against bacillary dysentery, enteritis, food poisoning, as an adjunct to antidote against pesticide poisoning, for poisonous snake bites, bleeding wounds, scald and burns and upper respiratory tract infections. In the mountainous areas of Java (Indonesia) it is sometimes grown as an ornamental. In Hawaii, a brown dye is derived from the leaves, and the fern is said to cure various female maladies, e.g. pre-menstrual syndrome. The attractive, fine leaves are also used to decorate hula altars and are often used as a kind of garland around the neck or on the head.
Production and international trade
Although O. chinensis is an attractive fern, it is only rarely grown and statistics on production or trade are not available.
In the Philippines, histochemical tests revealed the presence of alkaloids, amygdalin, saponin, oxalic acid, arbutin, tannin, formic and tartaric acid in the petiole and rachis of O. chinensis .
Rhizome short-creeping, 2-4 mm in diameter; scales uniseriate except for the base, acicular, up to 4 mm long, dark to reddish-brown. Leaves clustered, olive-green, brown to blackish when dry, herbaceous to chartaceous; petiole5-60 cm long, 0.6-1 times as long as the lamina (shorter and more slender in juvenile fertile plants), terete, 1.5-3 mm in diameter in the middle, upward gradually sulcate, the groove broad and flat, glabrous and lustrous green to yellow-brown; lamina lanceolate, oblong, elongate-ovate or narrowly triangular, 10-85 cm × 12(-25) cm, rarely smaller in fertile plants; fertile leaves at the base from bipinnate-pinnatifid up to quadripinnate-pinnatifid in large specimens; rachis stramineous, glabrous, subterete, upward gradually flattened; pinnae 6-10 to a side in larger leaves, free, strongly ascending to strongly spreading, basal ones usually subopposite, apically gradually alternate, smaller and closer, lower ones somewhat reduced; stalk 0.2-3 cm long; pinna elongate-triangular or elongate-rhombic, (5-)10-20 cm × (1.5-)3-10 cm, 2-4.5 times as long as wide, base usually with unequal sides, the acroscopic side broader as the pinna is strongly anadromic and this side has longer or less ascending pinnules, apex acuminate, often with 6-8 major, alternating, ascending pinnules to a side; pinnules triangular to rhombic, often twice as long as wide, shortly stalked, acute or acuminate; ultimate free divisions rhombic, asymmetrical, pinnatisect on both sides, the smaller ones cuneate, unequally and shallowly bifid or, if deeply bifid, usually once again bifid, linear spatulate to cuneate, margins of the lobes entire. Sori on the apical margin of the segments; indusium attached to the base and sides, on 1-3(-4) vein ends, brownish and chartaceous when dry; with more or less straight to convex base, adnate, convex sides, and straight, slightly convex or sometimes erose-denticulate free margin, more or less equalling the segment margin, never reflexed at maturity. Spores monolete, ellipsoid, smooth, medium brown.
Growth and development
Not much is known about the growth and development of O. chinensis . Its gametophytes have hardly been described although it is a widespread fern which easily colonizes. It primarily reproduces by outcrossing but it may also possess a mixed-mating system. On the prothallus several gregarious archegonia develop on the distal centre of the cushion near the sinus. Archegonia have a long neck, 90-100 μm long, bending toward the posterior side; the globose antheridia develop scattered between the archegonia.
Other botanical information
Opinions about the correct classification of O. chinensis vary extremely. In "Ferns of Malaya", Holttum placed it in Dennstaedtiaceae, Lindsaya subfamily and named it Sphenomeris chusana (L.) Copel. In "Flora Malesiana" it is placed in the Lindsaea -group (no family) as Sphenomeris chinensis (L.) Maxon; later, however, Kramer moved it to Dennstaedtiaceae , changing the name to Odontosoria chinensis (L.) J. Smith. In the "Flora of Thailand" it is placed in Lindsaeaceae as Sphenomeris chinensis . Regardless of the difficulties in classification, O. chinensis is easily recognized by the finely dissected leaves ending in narrow, parallel-sided, entire segments which widen at the apex to accommodate the pocket-shaped, indusiate sori. O. chinensis is very variable and 4 varieties have been distinguished which, however, are not quite distinct and overlap in distribution range throughout South-East Asia:
- var. chinensis . Lamina of variable length; segments gradually broadened to the apex, apical margin not or scarcely incised; sori often several together to a segment, rarely one except in the upper reduced segments, mostly with 2 or 3 veins; spores 42-48 μm long.
- var. divaricata (Christ) Kramer (synonym: S. chusana (L.) Copel. var. tenuifolia Holttum). Lamina over 20 cm long; segments suddenly spatulate-dilated at the apex to accommodate the sorus, apical margin often incised; sori one or two together in a segment, mostly with one vein; spores mostly 55-60 μm long.
- var. rheophila Kramer. Lamina 15-20 cm long; segments stiff, often with more or less revolute margin, gradually broadened to the apex, apical margin entire or sinuate; sori one or two together in a segment, mostly with one vein; spores elongate, bean-shaped, 44-48 μm long, about twice as long as broad.
- var. rubens Amoroso & Medecilo. Distinguished in the Philippines for specimens with reddish petiole and rachis.
O. chinensis grows terrestrially and on rocks from 100-2500 m altitude, on river banks, in thickets and open forests, in exposed or lightly shaded locations, often near hollow roads, on slopes, escarpments and on open banks (frequently by path-sides) in the mountains. It is found on infertile, not too dry, badly-drained soils, especially on steep banks. It also occurs in fields with alang-alang ( Imperata cylindrica (L.) Raeuschel). Locally it can be abundant and behave like a weed.
O. chinensis grows well in pots in the shade. It needs well-drained soils and adequate watering. It tolerates cool to warm conditions.
Genetic resources and breeding
Germplasm collections or breeding programmes for O. chinensis are not known to exist. It is unlikely that it is endangered by extinction or genetic erosion because of its wide distribution in a multitude of habitats, but germplasm collection is recommended.
Since O. chinensis is an attractive fern that can also be grown in pots, its potential as an ornamental needs to be investigated. Its dye and medicinal uses require further research to detect the active compounds and the possibilities for commercialization.
- Backer, C.A. & Posthumus, O., 1939. Varenflora voor Java [Fern flora for Java]. 's Lands Plantentuin Buitenzorg, Archipel Drukkerij, Buitenzorg, Dutch East Indies. p. 108.
- Holttum, R.E., 1966. A revised flora of Malaya. 2nd Edition. Vol. 2. Ferns of Malaya. Government Printing Office, Singapore. pp. 341-342.
- Kramer, K.U., 1971. Lindsaea Group. In: van Steenis, C.G.G.J. & Holttum, R.E. (General editors): Flora Malesiana, Series 2. Pteridophyta (Ferns & fern allies). Vol. 1, part 3. Martinus Nijhoff / Dr W. Junk Publishers, The Hague, The Netherlands. pp. 179-184.
- 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. pp. 38-39.
W.P. de Winter