3180

15(2): Cryptogams: Ferns and fern allies

Equisetum ramosissimum Desf.

Fl. atlant. 2: 398 (1799).

EQUISETACEAE

2n = 216

Equisetum ramosum DC. (1806), Equisetum elongatum Willd. (1810), Hippochaete ramosissima (Desf.) Börner (1912).

Branched horsetail (En). Indonesia: bibitungan (Sundanese), rumput betung (Sumatra), tropongan (Javanese). Papua New Guinea: niglgakagl. Philippines: putod, sumbok (Bukidnon), putuptud (Bontoc, Igorot). Thailand: ya nguak, ya thot bong, ya hu nuak (northern). Vietnam: c[or] d[oos]t.

Equisetum ramosissimum is widespread, from southern and eastern Africa, southern and central Europe throughout Asia to Central and South America. In South-East Asia only subsp. debile (Roxb. ex Vauch.) Hauke is found.

The stems of Equisetum L. accumulate crystals of silica and the fine abrasive action of these crystals make it a useful cleaning agent. Throughout New Guinea Equisetum ramosissimum is used to clean cooking and eating utensils. The sandpaper-like qualities lead to its use in shaping and smoothing tools, ornaments and weapons. In Indonesia and Malaysia, Equisetum ramosissimum stems are powdered and made into an ointment which is used externally to treat bruises, fractures and arthritis. A decoction is drunk as a diuretic and astringent to treat dysentery and haemorrhoids. In India it is used as diuretic and given against gonorrhoea. In Nepal juice of the roots (about 4 teaspoons 4 times a day for a week), is given to relieve fever. In South Africa, juice from the plant is used to relieve toothache and applied to the wounds after tooth extraction. In Papua New Guinea, horsetail is crushed together with leaves of Ficus sp., Impatiens sp. and Stellaria sp. and the sap is drunk to soothe a bad cough. In European traditional and modern alternative medicine several horsetail species were commonly used as diuretic and in baths to treat dropsy, urinary complaints and kidney affections. Equisetum arvense L., Equisetum palustre L. and Equisetum variegatum Schleich. were prescribed as 'Herba Equiseti maioris' to cure gonorrhoea and diarrhoea. About 4 g of the dried herb, powdered and taken 3—4 times a day, was used as a remedy for spitting blood, remineralizing organisms with retarded growth, especially in cases of tuberculosis, where the pulmonary tissues were affected by lesions. It was also applied as a haemostatic, diuretic, digestive agent and purifier. The ashes of Equisetum are administered in doses of 0.2—0.6 g and considered valuable in treating an acid stomach, dyspepsia, tuberculosis, pain in the bones, gastric and intestinal ulcers, bleeding, blood in the urine and difficulty in urinating. The juice of the fresh plant is used as well, in doses of 20—50 g/l per day. A strong decoction acts as an emmenagogue; it is also cooling and astringent and used for haemorrhage, cystic ulceration and ulcers in the urinary passages. Applied externally the decoction stops bleeding, heals wounds and reduces swelling of the eyelids. In Chinese medicine various Equisetum species have been applied. Equisetum hyemale L., Equisetum arvense L. and Equisetum ramosissimum are the sources of the drugs 'mùzéi' and 'wènjing' which serve as an astringent, haemostatic and diuretic. Wènjing is also used as a diaphoretic and to cure eye-diseases, catarrh, urinary calculus and hyperpepsia. There is confusion, however, as to the common names and identity of the drug plants. Moreover, both drugs share a synonym name ('jiéjiécão'). Equisetum ramosissimum has been identified in samples of mùzéi, but it is possible that all these species do not vary much in their properties and that the species most easily obtainable is used. It is striking that Equisetum species were applied in similar ways independently in Asia and Europe, as well as in South America by the Indians of Peru.
Equisetum ramosissimum is often cultivated as a pot plant. The stems are sometimes made into handicraft objects, e.g. picture frames.

Equisetum species are of diminishing economic importance but are still locally traded as crude drugs. The stems of Equisetum ramosissimum are traded in Indonesian traditional medicine as 'greges otot' or 'greges tulang'.

Equisetum contains high levels of silica and potassium but the chemical contents are not yet fully known. Equisetum species accumulate minerals in their tissue up to 125 ppm. In gold-rich areas as much as 610 g of gold per t Equisetum has been recorded. Some contain alkaloids (palustrine, palustridine, nicotine, equisetine), thiaminase, glycosides (dimethylsulphon), aconitinic acids, saponins (equisetonoside), 3-methoxypyridine, ß-sitosterol, equisetolic acid and equisetonine. The rhizomes contain a considerable quantity of starch cells. Some species are poisonous to livestock whereas others are used as fodder. Equisetum species also contain a thiaminase and the effects of poisoning in animals from ingestion of the plants are similar to those of vitamin B₁ deficiency. Equisetum ramosissimum is almost certainly toxic and it irritates the skin. In analysis, ß-sitosterol and stigmasterol were found as well as unidentified C₂₈ to C₃₂ carbohydrates. Equisetum ramosissimum plants show considerable thiaminase activity combined with a relatively low thiamine content. In the Philippines, horses are most susceptible to the stem of horsetail, and cattle and sheep also suffer ill effects due to poisonous principles it contains. High rates of nitrogen fixation by acetylene reduction are realized by Enterobacteriaceae associated with the roots of Equisetum ramosissimum. In in-vivo and in-vitro tests Equisetum ramosissimum subsp. debile proved effective in inhibiting many phyllosphere fungi.

A very characteristic plant with jointed, hollow stems, branches in whorls around the stem, apparently without leaves and spores produced in a terminal, cone-like strobilus. Rhizome rather deep underground, erect or ascending, with many ascending, dark brown to black branches, somewhat rough, 6—8-sectored. Roots numerous, wiry along the length of the rhizomes. Stem irregularly branched or simple, erect or ascending, cylindrical, 15—300(—900) cm x 2—3(—15) mm, articulate with hollow internodes, smooth, evergreen (green to greyish-green); ridges 10—32, convex, usually with small cross-bands of silica, grooves with flat-topped rosettes; stomata arranged in one line on each side of the groove, 71—102 µm x 56—78 µm. Branches solitary or in groups of 2—3(—5), erect, straight or sinuous, simple or occasionally branched, up to 60 cm long, with 6—10 ridges. Leaves small, scale-like, in whorls that fuse into a sheath at the stem nodes; sheath cylindrical to slightly funnel-shaped, 4.5—13 mm x 2—12 mm, its segments smooth, the midrib prominent basally, becoming flattened apically, with 2 distinct lateral ridges, ribs flattened, angular at the sides, green, teeth thin, with a brown central band and white or colourless margins, drying or deciduous, leaving a truncated margin on the sheath; sheath of the branches like the ones of the stem or retaining the teeth, the first internode much shorter than the corresponding stem sheath. Strobilus cone-like, ellipsoid, up to 17 mm x 7 mm, apex subobtuse to apiculate with 1 mm apiculum, yellow to black; sporangiophore consists of a short stalk at right angle to the axis of the strobilus, peltately attached to a plate-like, flat, hexagonal structure bearing 5—10 sporangia on its underside. Spores globose, each one bearing 4 filiform, long, apically clavate, hygroscopic appendages (elaters), surface granulate with scattered spherical deposits, bright green.

The hygroscopic elaters of the spores of Equisetum ramosissimum, which stand out in dry air but quickly contract in moister circumstances, combine several functions that make the spores more susceptible to dispersal by wind in areas unfavourable for germination. The spores contain chlorophyll and remain viable for only a few days after they are released. The absence of a transpiration-resistant spore wall makes them vulnerable to desiccation. Under favourable conditions the spores germinate within a day. Within a few weeks the prothallus develops as an elongated, fleshy structure with upright, photosynthetically active appendages. The larger prothalli may live for months, in culture even up to two years. The prothalli are either male or bisexual. A prothallus may have as many as 200 archegonia many of which are fertilized, although the vast majority do not develop into mature sporophytes. It is not unusual for 8—10(—15) sporophytes to develop from a single gametophyte. The rhizomes of the sporophytes produce aerial stems at close intervals, together often forming dense colonies. Mature plants fruit all year round and show no seasonality.

Equisetum L. is the only genus in the family Equisetaceae and comprises 15 species. It is a relict group with a long fossil history and is cosmopolitan except in Australia, New Zealand and Antarctica. The many unique features of its anatomy and morphology justify its being segregated as a distinct class, subdivision or even, by some authors, a division of the plant kingdom. Equisetum has been subdivided into 2 subgenera, subg. Equisetum (stomata superficial, strobili blunt, stem smooth or a little rough) with 8 species and subg. Hippochaete (stomata sunken, strobili apiculate, stem rough from silica deposits) with 7 species, including Equisetum ramosissimum Desf.
Equisetum ramosissimum is variable and has been subdivided into 2 subspecies:
— subsp. ramosissimum: stem with double common endodermis (an inner endodermis surrounding all bundles); stomata in one to several lines; sheath-teeth persistent; from southern and eastern Africa, southern and central Europe to most of Asia except Malesia.
— subsp. debile (Roxb. ex Vauch.) Hauke (synonyms: Equisetum debile Roxb. ex Vauch., Equisetum laxum Blume, Equisetum timorianum Vauch.): stem with individual endodermis (an endodermis surrounding each vascular bundle); stomata in one to several lines; sheath-teeth regularly breaking off; India, southern China, throughout Malesia (except Peninsular Malaysia) to New Caledonia.
In the area of geographical overlap, however, there is an extensive intergradation between the two subspecies. Fertile, intermediate hybrids of the two subspecies have been recorded in India, southern China and the Ryukyu Islands.

Equisetum ramosissimum is found in marshes and abandoned rice fields, in meadows along streams or trails, or attached to rocks in streams, from humid lowlands up to severe alpine conditions at 3600 m altitude. The stem may remain tufted and small when growing in sandy soils along river banks, but attains a height of several m when growing in shady and swampy soils of forests. It may profit from soil disturbance, for example by logging or the establishment of plantations. It has become a weed that thrives gregariously on the rice terraces of the Philippines and in the tea plantations of Sumatra.

Equisetum ramosissimum can be propagated by spores but much more easily by rhizome cuttings.

Rhizoctonia solani may cause root rot and stem rot in Equisetum ramosissimum, whereas Gloeosporium may damage the leaves.

The barren stems of Equisetum ramosissimum are cut off just above the root.

Equisetum ramosissimum is used either fresh or dried, but allegedly it is more effective when fresh. A fluid extract is prepared from it and the ashes are also employed.

The variability of Equisetum ramosissimum subsp. debile is small. Neither substantial germplasm collections nor breeding programmes are known to exist.

Equisetum ramosissimum is common in South-East Asia and its medicinal properties in particular need better investigation. Its use in traditional medicine all over the world makes it an interesting and promising plant resource.

Croft, J.R., 1985. Ferns and fern allies. In: Leach, G.J. & Osborne, P.L., (Editors): Fresh water plants of Papua New Guinea. University of Papua New Guinea Press, Lae, Papua New Guinea. pp. 33-74.
Dorstal, J. & Reichstein, T., 1984. Pteridophyta. In: Kramer, K.U. (Editor): Hegi, G., Illustrierte Flora von Mitteleuropa. Band 1, Teil 1. Paul Parey, Berlin, Germany. pp. 54-79.
Duckett, J.G., 1979. Comparative morphology of the gametophytes of Equisetum subgenus Hippochaete and the sexual behaviour of Equisetum ramosissimum subsp. debile (Roxb.) Hauke, Equisetum hyemale var. affine (Engelm.) A.A. and Equisetum laevigatum A. Br. Botanical Journal of the Linnean Society, London 79(3): 179-203.
Ghassemi, N. & Ghanadi, A.R., 1993. A study on the morphology and phytochemistry of some Iranian Equisetum species. 41st Annual congress on medicinal plant research, Dusseldorf, Germany, 31 August-4 September 1993.
Hauke, R.A., 1963. A taxonomic review of the genus Equisetum subgenus Hippochaete. Beiheft Nova Hedwigia: 1-123.
Holdsworth, D. & Sakulas, H., 1992. High altitude medicinal plants of Papua New Guinea. Part 2. Mount Wilhelm, Simbu Province. International Journal of Pharmacognosy 30(1): 1-4.
Kanaujia, R.S., 1977. Studies on phyllosphere fungi 5. Effects of plant extracts on leaf surface fungi of Brassica campestris var. sarson. Iranian Journal of Plant Pathology 13(3-4): 39-50.
Laferrière, J.E., 1998. Equisetaceae. In: Kalkman, C. & Nooteboom, H.P. (Editors): Flora Malesiana. Series 2. Pteridophyta. Ferns and fern allies. Vol. 3. Rijksherbarium/Hortus Botanicus (under the auspices of Foundation Flora Malesiana), Leiden, The Netherlands. pp. 287-288.
Meyer, P., 1989. Thiaminase activities and thiamine content of Pteridium aquilinum, Equisetum ramosissimum, Malva parviflora, Pennisetum clandestinum and Medicago sativa. Onderstepoort Journal of Veterinary Research 56(2): 145-146.
Nitta, A., Yoshida, S. & Tagaeto, T., 1977. A comparative study of crude drugs in Southeast Asia.10. Crude drugs derived from Equisetum species. Chemical and Pharmaceutical Bulletin (Tokyo) 25(5): 1135-1139.

Dedy Darnaedi, N. Wulijarni-Soetjipto & W.P. de Winter

Darnaedi, D., Wulijarni-Soetjipto, N. & De Winter, W.P., 2003. Equisetum ramosissimum Desf.. In: de Winter, W.P. and Amoroso, V.B. (Editors): Plant Resources of South-East Asia No 15(2): Cryptogams: Ferns and fern allies. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea