Sphagnum (PROSEA)
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Introduction |
Sphagnum L.
- Protologue: Sp. pl. 2: 1106 (1753); Gen. pl. ed. 5: 487 (1754).
- Family: Sphagnaceae
- Chromosome number: x= 19
Major species and synonyms
- Sphagnum cuspidatum Hoffm., Deutschl. Fl. 2: 22 (1796), synonym: S. flaccidifolium A. Johnson.
- Sphagnum junghuhnianum Dozy & Molk., Bryol. Jav. 1: 27 (1854), synonym: S. gedeanum Dozy & Molk.
- Sphagnum perichaetiale Hampe, Linnaea 20: 66 (1847), synonyms: S. beccarii Hampe, S. holttumii A. Johnson, S. japonicum Warnst. var. philippinense Warnst.
Vernacular names
- Peat moss, bog moss (En).
- Philippines (Tagalog): lumot.
Origin and geographic distribution
Sphagnum consists of at least several hundreds of species and is nearly cosmopolitan in range, though usually confined to mountains in the tropics. The three species treated here are widespread in Malesia. S. cuspidatum occurs throughout almost all of the northern Hemisphere, S. junghuhnianum is widespread in tropical and subtropical Asia, and S. perichaetiale has an almost pantropical distribution.
Uses
Sphagnum is used widely in the floral industry for wreaths or to line hanging baskets. Because of its peculiar leaf structure, which enables the plant to absorb and store water many times its own weight, Sphagnum is often used in potting new plants in greenhouse propagation practices. Mixed with humus, it is a good germinating medium for seeds of many economically important plants. Less frequently Sphagnum is used in boxing fragile commodities for transport. At the crocodile breeding station in Palawan Island (the Philippines), it is used as a cushion or layering material for the incubation of reptilian eggs collected from the wild. In Europe and Asia during the Second World War, Sphagnum was used extensively as antiseptic wound dressing pad to stop bleeding.
In South-East Asia, unlike in temperate countries, Sphagnum bogs have not been exploited as a fuel source owing to the relatively small biomass formed in tropical mountains. For this purpose, the dead, partially decomposed material accumulating in the lower levels in the peat bog is used. This material is also widely used by gardeners as a soil amendment.
Production and international trade
The small commercial supplies of Sphagnum sold in local markets in South-East Asian countries have always been taken from the wild. The market price of a kilo of pure Sphagnum moss in Manila was about US$ 1 in 1986. No international trade of Sphagnum from the Malesian region exists.
Properties
Chemical analysis of Sphagnum moss showed the presence of glucose and disaccharide, as well as several organic acid compounds. Antibiotic activity of a peat moss extract has been reported against gram-positive bacteria.
Description
Autoecious or dioecious mosses growing in variously coloured tussocks, often forming extensive carpets; stems soft, tufted, often long, differentiated into a cortex of 1-4 layers of often hyaline cells surrounding a central cylinder; branches in fascicles of (1-)2-8, usually differentiated into spreading and pendent branches. Leaves arranged spirally with a 2/5 phyllotaxy, midrib absent; stem leaves often triangular or lingulate in shape, branch leaves lanceolate, oblong to linear; leaf cells in a single layer, consisting of 3 main types: elongated border cells, narrow, living green cells and inflated dead hyaline cells, the latter often with wall fibrils and pores. Sporophytes infrequently produced. Capsule globose, borne on top of a short transparent stalk which is the extension of the branch subtending archegonia; lid convex, lacking a peristome.
Growth and development
In general, Sphagnum grows slowly. Growth may be slightly over 5 cm/year, but it is much less at higher altitudes. Ripe capsules shrink in dry weather to build up internal pressure, blowing off the lid and ejecting the spores, but this mechanism frequently does not work, and then the lid merely falls off or the capsule disintegrates.
Ecology
The Sphagnum bog developed in Malesian mountains belongs mostly to the blanket type and covers wet slopes or cliff faces in shaded sites. Blanket bogs develop on acid, mineral-deficient soils, where draining is poor, and peat accumulates year by year. The bogs may cover large areas of level and sloping ground, like a blanket. However, small floating bogs of Sphagnum exist around the margin of high mountain lakes, e.g. on Mount Apo in the Philippines. The well-known ecological role played by peat mosses in the succession of aquatic to terrestrial ecosystems, such as that seen in temperate and boreal bogs, has not been documented for South-East Asia. Blanket bogs are very important locally in the water and soil conservation of tropical mountain ecosystems. They are also the germinating and growing sites of acid-loving plants such as the insectivorous Drosera species and ferns such as Matonia species.
Management A disease called cutaneous sporotrichosis causing ulcerous skin lesions is caused by a fungus that may be present in Sphagnum moss. This disease is known in the United States, but may occur elsewhere. It is advised that people who regularly work with fresh or dried peat moss wear gloves and long sleeves to avoid direct contact with cuts or scrapes in the skin.
Genetic resources
Local market consumption of Sphagnum mosses depends on the wild populations of these slow growing plants. Thia creates a perennial risk of overexploitation or over-depletion of this ecologically important plant resource.
Prospects
Peat moss will probably remain a plant product of minor importance in South-East Asia, used particularly in gardening practices. There seems no scope for increasing production and trade due to a limited demand, combined with the limited supply from natural populations and the absence of possibilities for commercial cultivation.
Literature
- Ablao, F.C.C., 1986. A survey of different species of Philippine bryophytes sold commercially around Greater Manila Area. B. Sc. (Botany) thesis, University of the Philippines at Los Baños, Laguna.
- Banerjee, R.D. & Sen, S.P., 1979. Antibiotic activity of bryophytes. Bryologist 82: 141-153.
- Eddy, A., 1977. Sphagnales of tropical Asia. Bulletin of the British Museum (Natural History), Botany 5(7): 359-445.
- Johnson, A., 1980. Mosses of Singapore and Malaysia. Singapore University Press, Singapore. 126 pp.
- Ting, H.-S., 1982. Spore producing medicinal plants in China. Scientific Technology Publisher, Shanghai, China. 409 pp.
Authors
Benito C. Tan
