Horsetails
What are they?
The horsetails are a primitive lineage of plants, with fossil examples dating back to the time of the dinosaurs, when these plants dominated the vegetation in many areas before the flowering plants got going. These are plants which, like ferns and mosses, produce spores rather than seeds and these appear in cone-like structures, carried at the top of the stems. The stems are typically hollow in the centre and ridged on the outside, while the leaves are reduced to small, bract-like structures, appearing in whorls at intervals along the stem.
Where are they found?
Most horsetails favour moist sites, from wet woodland to even growing from standing water. Field Horsetail is less fussy and can be a problem weed of cultivated places on heavier soils.
Identification
Important features to note include the colour of stems at the bases of the leaf whorls; presence or absence of side branches and whether they are branched or simple; the size of the hole down the centre of the stem; the habitat. The spore 'cones' usually appear in spring or early summer and their structure can be useful for identification, especially whether they appear on regular green stems, or appear on leafless, brownish or straw-coloured stems, early in the season.
Field Horsetail Equisetum arvense
An abundant species of damp, heavy ground. Cones on pale brownish, unbranched stems in April-May and withering as the green, branched stems emerge. Stems with 6-19 ridges and of two types - stands of straight, upright stems, or mats of curled or twisted stems, all growing from a far-reaching, deep-seated and persistent root stock.
|
|
|
|
|
|
Great Horsetail Equisetum telmateia
A local plant in East Anglia, where it is rather scattered in Norfolk but more common in South Suffolk, growing in damp hollows, shady streamsides and damp hedgebanks. Cones on pale brownish, unbranched stems in April and withering as the green, branched stems emerge. The upright stems have 20-40 ridges on them and can reach up to two metres in height. Brownish leaves relatively long and bristle-like.
|
|
|
|
Marsh Horsetail Equisetum palustre
A common plant of damp soils, occasionally found in standing water but most often found in herb-rich, river valley grasslands and marshy places. Narrow cones carried on green, branched stems and ripening in June. The upright stems grow to around 50cm in height and have 6-10 ridges on them, while the central hollow is narrow. Blackish leaves relatively stout with pale edges.
|
|
|
Water Horsetail Equisetum fluviatile
Widespread and locally common in very wet, marshy places and often growing directly from standing water along pond edges. Cones short and relatively blunt, carried on green, unbranched or only shortly-branched stems and ripening in June. The upright stems typcially grow to around 50cm in height but may reach 150cm. Stems have 10-30 ridges on them but these are low and almost smooth, while the central hollow is large, leaving a rather weak outer rim. Leaf sheaths green, the dark leaves relatively short with pale tips.
|
|
|
|
Rough Horsetail Equisetum hyemale
A rare, introduced species in East Anglia, currently known from just two sites in Norfolk. Pointed cones carried on green, unbranched stems and ripening in February to April. The upright stems grow to around one metre in height and have 10-30 ridges on them; unlike other species on this page, they remain green and do not die back over winter. The blackish and off-white leaf sheaths are prominent on the branchless stems.
|
|
|
|
Wood Horsetail Equisetum sylvaticum
This species is more typical of shady woodland on acid soils further north and west in the UK and, in East Anglia, it is currently only known from a single site in North Norfolk. Cones carried on pale green, unbranched stems and ripening in May. The regular stems grow to around 50cm in height and have 10-18 weak ridges on them. Stems carry many, gracefully weeping side branches which are themselves branched again. The leaves are distinctive, being relatively broad and a rusty brown in colour.
|
|
|
|