Equisetum


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Related to Equisetum: Equisetum arvense

Equisetum

 

(horsetail), a genus of perennial herbs of the family Equisetaceae. Many species are evergreens. From the strongly branched rhizome depart longitudinally grooved aboveground shoots, which, like the rhizome, are segmented into regularly alternating nodes and hollow internodes. The nodes bear whorls of poorly developed leaves; the leaves are fused below in the sheath that embraces the base of the internode. Also departing from the nodes are branches that are arranged in whorls and that penetrate the fused bases of the leaves. The epidermis of the stem is impregnated with silica, which gives the stem rigidity. Photosynthesis is effected by the green stems and branches, since the leaves are poorly developed. Horsetails reproduce by spores, which develop in sporangia on corymbiform sporophylls. The spores are equipped with hygroscopic filaments, or elaters, that promote distribution.

There are about 30 species, distributed throughout the world except in Australia and New Zealand. Most species are slender and low, measuring less than 1 m in height. Exceptions include the climbing tropical South American E. giganteum, which reaches 12 m in length and about 3 cm in diameter, and the Mexican E. schaffneri, whose stems reach about 2 m in height and 10 cm in diameter.

The USSR has 13 or 14 species, growing in swamps, forests, meadows, fields, and bodies of water. A number of species, including E. variegatum, E. scirpoides, and E. sylvaticum, are eaten by deer, certain domestic animals, and game animals (for example, hares, partridges, and black grouse). E. hiemale, which contains a great deal of silica, is used by the local population for polishing. E. arvense, a pernicious weed whose rhizome penetrates deep (1 m or more) into the soil, is sometimes used medicinally—as a diuretic—in the form of an infusion or liquid extract. E. palustre is poisonous to agricultural animals.

M. E. KIRPICHNIKOV

References in periodicals archive ?
Golub and Whetmore (1948) excavated the rhizome system of a colony of Equisetum arvense to a depth of 2 m and found five successive horizontal layers of rhizomes connected by vertical rhizomes.
Hepatopro-tective and free radical scavenging activities of phenolic petrosins and flavonoids isolated from Equisetum arvense.
Los trabajos recientes en el genero Equisetum son abundantes, de caracter taxonomico, sistematico y evolutivo (Pryer et al.
Kim, "Hepatoprotective and free radical scavenging activities of phenolic petrosins and flavonoids isolated from Equisetum arvense," Journal of Ethnopharmacology, vol.
8 Cochlearia officinalis Equisetum arvense 3 Equisetum variegatum 1.
Any display which works to break health taboos must be good, and I found the plantation of dicksonias, cycads, equisetum and ferns exhilarating.
DAVID MORHICKMAN AIT is mare's tail, Equisetum arvense, probably the hardest weed to eradicate.
David Morhickman, by email CAROL: It is mare's tail, Equisetum arvense, probably the hardest weed to eradicate.
Interspecific and intraspecific variation of phenolics in the genus Equisetum subgenus Equisetum.
In vitro In vivo animals Anti-inflammatory [27] In vivo animals Spasmolytic [28] In vitro Antimicrobial [29] In vivo animals Diuretic [30] In vivo animals Adaptogenic [26] Equisetum In vitro Antimicrobial [31,32] arvense (L.
Tenders are invited for Supply of medicine Digitalis purpura, Dioscorea villosa, Drosera rotundifolia, Dulcamara, Echinacea angustifolia, Equisetum hyemnale, Eupatorium perfoliatum, Euphrasia officinalis, Eel serum,Ferrum metallicum,