Equisetum ramosissimum subsp. ramosissimum
Aerial stems persisting more than a year, regularly branched, 32–250 cm; lines of stomates occasionally doubled; ridges 10–16. Sheaths greatly elongate, 8–12 × 3–6 mm; proximal sheaths brown with darker girdle, distal sheaths green; teeth 10–16, not articulate but often thin and drying. Cones pointed at their apex; spores green, spheric.
Phenology: Cones maturing in summer.
Habitat: Moist sandy or clay areas
Elevation: 0–100 m
Distribution
Introduced; Fla., La., N.C., s, c Europe, Asia, Africa.
Discussion
Equisetum ramosissimum subsp. ramosissimum apparently was introduced from Europe with ballast (R.L. Hauke 1979). Equisetum ramosissimum subsp. debile (Roxburgh) Hauke occurs in southeast Asia and the southern Pacific Islands. Where the ranges of the two subspecies overlap, fertile, morphologically intermediate individuals are found (R. L. Hauke 1963).
Selected References
None.