EQUISETACEAE

HORSETAIL FAMILY

Richard L. Hauke

Perennial from rhizome (above ground stem annual or perennial herb)
Stem generally erect, ridged lengthwise, hollow except at nodes, sometimes of 2 kinds (sterile, fertile); branches 0 or whorled and alternate leaves, sometimes solid
Leaves scale-like, whorled, fused into nodal sheath with as many teeth as leaves, generally not green
Sporangia several on inner surface of peltate scales that are clustered into a terminal cone; spores of 1 kind per sp., spheric, green, unmarked, with 4 strap-like appendages
Genera in family: 1 genus, 15 species: worldwide except Australia, New Zealand
Reference: [Hauke 1978 Nova Hedwigia 30:385–455]

EQUISETUM

HORSETAIL, SCOURING RUSH

Etymology: (Latin: horse, bristle, from roots of E. fluviatile L.)

Native

E. laevigatum A. Braun

SMOOTH SCOURING RUSH

Stem annual (or perennial herb in s), of 1 kind, 30–180 cm, green, unbranched; sheath 6–15 mm, longer than wide, generally with 1 dark band at tip, teeth 10–26, generally deciduous
Sporangia: cone tip rounded
Ecology: Moist, sandy or gravelly areas
Elevation: < 3000 m.
Bioregional distribution: California Floristic Province, Modoc Plateau, White and Inyo Mountains, Desert Mountains
Distribution outside California: to British Columbia, eastern US
Synonyms: E. funstoni A.A. Eaton; E. kansanum J. Schaffner
Horticultural information: IRR: 1, 2, 3, 4, 5, 6, 7, 14, 15, 16, 17, 22, 23, 24 &SHD: 8, 9, 18, 19, 20, 21; INV.