Equisetum ramosissimum Desf.
Family
Equisetaceae
Synonyms
Equisetum ramosum DC., Equisetum elongatum Willd., Hippochaete ramosissima (Desf.) Börner.
Vernacular Names
| English |
Branched horsetail. |
| 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. |
Geographical Distributions
Equisetum ramosissimum is widespread, from southern and eastern Africa, southern and central Europe throughout Asia to Central and South America. In Southeast Asia, only subsp. debile (Roxb. ex Vauch.) Hauke is found.
Description
Equisetum ramosissimum is a very characteristic plant with jointed and hollow stems. The branches are in whorls around the stem, apparently without leaves and the spores are produced at the terminal of branches. The rhizome is rather deep underground, erect or ascending, with many ascending, dark brown to black branches, somewhat rough and 6-8-sectored. The roots are numerous and wiry along the length of the rhizomes.
The stem is irregularly branched or simple, erect or ascending, cylindrical, measuring 15-300(-900) cm x 2-3(-15) mm, articulate with hollow internodes, smooth and evergreen (green to greyish-green). There are 10-32 ridges which are convex, usually with small cross-bands of silica and grooves with flat-topped rosettes. The stomata are arranged in one line on each side of the groove. It measures 71-102 µm x 56-78 µm. The branches are solitary or in groups of 2-3(-5), erect, straight or sinuous, simple or occasionally branched, measuring up to 60 cm long and with 6-10 ridges.
The leaves are small, scale-like, in whorls that are fused into a sheath at the stem nodes. The sheath is cylindrical to slightly funnel-shaped, measuring 4.5-13 mm x 2-12 mm and with smooth segments. The midrib is basally prominent, becomes apically flattened, with 2 distinct lateral ridges, with flattened ribs, angular at the sides, green, with thin teeth, with a brown central band and white or colourless margins, drying or deciduous and leaving a truncated margin on the sheath. The sheath of the branches is like the ones of the stem or retaining the teeth. The first internode is much shorter than the corresponding stem sheath. The cone-like strobilus is yellow to black, ellipsoid, measuring up to 17 mm x 7 mm and nearly blunt to apiculate with 1 mm apiculum at apex.
The sporangiophore consists of a short stalk at the right angle to the axis of the strobilus. It is peltately attached to a plate-like, flat, hexagonal structure that bears 5-10 sporangia on its underside. The spores are spherical where each one bears 4 slender, long, club-shaped, apical, hygroscopic appendages (elaters), with granulate surface scattered with spherical deposits and bright green.
Ecology / Cultivation
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 metres 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.
Line Drawing / Photograph
References
- Plant Resources of South-East Asia No.15(2): Cryptogams: Ferns and fern allies.
