Vascular – Exotic
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
Terrestrial. Bare land, riversystems especially silty, sandy and gravely sites, streambanks.
Erect, colony-forming, summer-green perennial, primitive fern-ally to 10-80 cm. All aerial parts die back in winter. Extensive, deep, freely branching rhizomes with round tubers. Stems of 2 types. Sterile stems green, 10-80 cm long, 1-5 mm diam, jointed, hollow, ribbed or grooved, very rough to touch (containing silica), with lateral branches in whorls; leaves are 10 mm green sheaths. Resembles pine seedling. Fertile stems pale brown, shorter, joints larger, unbranched, with pale brown 14 mm sheaths; producing terminal cones; appearing in early spring before sterile stems and dying quickly after shedding spores. Cones conspicuous, 4-40 mm long. Spores seldom produced in NZ.
Equisetum hyemale rough horsetail is very similar but rare; has slender, taller, very rough, asparagus-like spears with black rings, no leaves, no (occ few small) branches, cones on green stems. E. fluviatile (rare).
equisetum: From the Latin equus ‘horse’ and setum ‘bristle’, the barren growths resembling horses’ tails.
arvense: Growing in arable fields
Reason For Introduction
Life Cycle Comments
Reproducing by spores instead of seeds, and by rhizomes, to which are attached small tubers. (Wax, Fawcett, Isley eds. 1981). Fruiting heads contain masses of tiny pale greenish spores in small pine-cone like structure. Stems tough and wiry, hollow, jointed, and of two types: fertile, producing fruiting heads and having large, easily separable joints, not branched; Sterile or vegetative, having much smaller joints, with lateral branches in whorls around the main stem. Leaves on sterile stems only, in the form of cup shaped toothed sheaths at the joints (Wax, Fawcett, Isley eds. 1981).
Plant is dispersed by river systems, soil movement, humans (popular with herbalists).
References and further reading
Brownsey, P., Moss, T.C., Sneddon, B.V. Cone production in Equisetum arvense. Wellington Botanical Society Bulletin, 42: 16-21
Campbell, E.O. 1971. Notes on Equisetum arvense in New Zealand. Wellington Botanical Society Bulletin, 37: 51-53
de Lange, P.J. 1988. A new equisetum species adventive in New Zealand. Auckland Botanical Society Journal, 43: 68-72.