Dipteris conjugata is a species of fern in the family Dipteridaceae. It has a rhizome, and 2-3 tall stems with mid green or dark green fronds, which have several divisions to toothed lobes. It is grows in clearings, mountain ridges and in forest margins, from tropical and temperate Asia, northern Queensland in Australia and some islands in the Pacific Ocean. It has limited native medicinal uses.
Description
It has a creeping rhizome covered with black shiny hairs or reddish brown hairlike scales.[2][3][4][5] The hairs are 4 to 5 mm long and 0.2 mm in diam.[6] The hairs are more like bristles on the older sections of the rhizomes.[4] It is up to 1 cm or more in diameter.[7]
The stipes (leaf stalks) are normally between 0.4–2.0 m (1 ft 4 in – 6 ft 7 in) long,[2][4] but stipes up to 2.5 m (8 ft 2 in) have also been found.[8] They have hair-like scales at base, which then becomes smooth and glabrous.[5][7] They are straw coloured to brown.[6]
The leaf stems appear at regular intervals along the rhizome.[4] and branch three or four times.[3] The rhizomes are usually terrestrial, but can also climb trees. The fronds are composed of two enormous leaflets, each up to 1 metre wide and broad.[9][10][11]
The fronds are mid green to dark green on the upper surface, and paler or glaucous underneath.[2][5][6] are between 0.5–0.7 m (1 ft 8 in – 2 ft 4 in) long and 0.5–0.7 m (1 ft 8 in – 2 ft 4 in) wide.[5][4][2] They are divided to the base into two fan-shaped halves, which are further divided more than halfway into 4 or more unequal lobes, which are again lobed one or more times. The ultimate lobes taper to a narrow apex with the edges deeply or coarsely toothed. The main veins branch into two veins several times.[7][5] The juvenile fronds are tomentose, i.e. with a layer of soft hairs.[2]
On the lower surface of the fronds are numerous small sori which are irregularly scattered and of irregular size and shape.[11][7][2][3][10][4] They do not have indusia (umbrella-like covers) and have paraphyses (filament-like support structures) which are club-shaped.[5][6]
Taxonomy
Illustration of the fern from Die Farnkräuter der Erde in 1897
In Fiji it is known as koukoutangane,[3][2] or 'aivuiniveli'.[15] In Thailand it is called bua chaek[16] and bua cek in Singapore,[17] It is written as 双扇蕨[5] or 破傘蕨,[2] in Chinese script, and known as shuang shan jue in Pinyin in China.[5]
D. conjugata grows on clay slopes,[6] in clearings,[17] ridges and on forest margins.[5][7] In East Kalimantan, Indonesia, it grows along rivers together with Nypa Palms.[7] In Borneo, it is found commonly growing with Histiopteris incisa (Thunb.) J. Sm. and Lygodium circinnatum (Burm.) Sw., along forest margins and paths.[22] In New Caledonia, it is found on sunny roadside banks.[10] The fern is also common in forest margins in high rainfall areas.[3]
The species occurs mainly at altitudes of 500 to 1,200 m (1,600 to 3,900 ft) above sea level in China,[5] 300 to 1,700 m (980 to 5,580 ft) in Malaysia,[4] and 300 to 2,900 m (980 to 9,510 ft) in Singapore.[7] In Singapore, it occurs on coastal cliffs,[17][2] and at the risk of landslides.[4][7] It is also
Conservation
This species has a varying status in different countries. In Singapore it is classed as critically endangered, in Queensland it has been assessed as near threatened, while in Cambodia, Thailand and Laos it is seen as having no threats, such that it was recommended to the IUCN that it be classed as least concern.[6][23][24] As of August 2024[update], it has not been assessed by the IUCN.
It has been used as a medicinal plant to treat various ailments,[27] such as in southern Thailand, the roots have been collected for used in traditional medicine.[7][17][2] In Fiji, it is used to treat male reproductive ailments.[2]
It also has another use, in the highlands of Mindanao in the Philippines, the large fronds are used as an umbrella.[7]
References
^ abHassler, Michael. "World Plants: Ferns and Lycophytes list". World Ferns. Synonymic Checklist and Distribution of Ferns and Lycophytes of the World. Retrieved 3 August 2024.
^ abcdefghiLok, A. F. S. L.; Ang, W. F.; Tan, H. T. W. (2009). "THE STATUS AND DISTRIBUTION IN SINGAPORE OF DIPTERIS CONJUGATA REINW. (DIPTERIDACEAE)". Nature in Singapore. 2: 339–345.
^Beddome, Col. R. H. (1892). Handbook of the Ferns of British India, Ceylon, and the Malay Peninsula. Calcutta: Thacker, Spink and Co. p. 336 plus engraving no. 185.
^Reinwardt, Caspar Georg Carl (1828). Hornschuch, Christian Friedrich (ed.). Sylloge Plantarum Novarum. Vol. 2. Regensburg: C. E. Brenck. p. 3. Retrieved 3 August 2024.
^"conjugate". The Free Dictionary. Retrieved 5 October 2019.
^H.B.R. Parham, 'Fiji native plants with their medicinal and other uses' Polynes. Soc. Mem 16 The Polynesian Society, page 160
Other sources
de Winter, W. P. & V. B. Amoroso (eds.), 2003. Plant resources of South-East Asia No. 15(2). Cryptogams: Ferns and fern allies. Prosea Foundation, Borgor, Indonesia. 268 pp.
Hnatiuk, R. J., 1990. Census of Australian vascular plants. Australian Flora and Fauna Series No. 11.
Holttum, R. E., 1954. Plant life in Malaya. Longmans, Green & Co.. London. 254 pp.
Holttum, R. E., 1966. A revised flora of Malaya. II Ferns of Malaya. Govt. Printing Office, Singapore (2nd ed.). 653 pp.
Lim, S., P. Ng, L. Tan & Y. C. Wee, 1994. Rhythm of the sea - The life and times of Labrador beach. School of Science, National Technological University & Department of Botany, National University of Singapore.
Parris, B. S., R. Khew, R. C. K. Chung, L. G. Saw & E. Soepadmo (eds.), 2010. Flora of Peninsular Malaysia. Series I: Ferns and Lycophytes. Vol. 1. Malayan Forest records No. 48. Forest Research Institute of Malaysia, Kepong. 249 pp.
Smitinand, T. & K. Larsen, eds. 1970-. Flora of Thailand.
Wee, Y. C., 2005. Ferns of the tropics. Times Editions-Marshall Cavendish, Singapore. 2nd ed. 190 pp.
Wee, Y. C. & R. Hale, 2008. The Nature Society (Singapore) and the struggle to conserve Singapore's nature areas. Nature in Singapore 1: 41-49.
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