Burke: Equisetum palustre vs. Equisetum telmateia

	Equisetum palustre	Equisetum telmateia
	marsh horsetail	giant horsetail
Habit	Rhizomatous annual, the stems not dimorphic, 2-8 dm. tall, with 5 to 10 deep grooves, the ridges smooth; stomates in a single, broad band in each furrow; central cavity less than 1/3 the diameter of the stem; sheathes green, 5-10 mm. long, with persistent teeth 3-7 mm. long, black or dark brown with broad, pale, papery margins.	Rhizomatous perennial, the stems dimorphic; sterile stems 5-30 dm. tall and 0.5-2 cm. thick, 20- to 40-ridged, the central cavity about 1/4 the diameter of the stem; stomates in 2 broad bands in the furrows; sheath 1-2.5 cm. long, with slender, tapered teeth 3-8 mm. long; fertile stems 2.5-6 dm. tall and 1.5-2 cm. thick; sheaths 2-5 cm. long, with 20-30 prominent teeth fused in groups of 2-4.
Leaves	Branches few and irregular to many and whorled, 5- to 6-angled, simple.	Branches only on sterile stems, whorled, ascending, 4- to 6-angled, solid, 1-2 mm. thick, sometimes again branched.
Spores	Cones pedunculate, blunt, deciduous.	Cone 4-7 cm. long.

	Equisetum palustre	Equisetum telmateia
Habitat	Streambanks, wet meadows, and marshes, from the lowlands to moderate elevations in the mountains.	Moist areas in the lowlands.
Distribution	Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across the northern U.S. and Canada to the Atlantic Coast; circumboreal. [WildflowerSearch map] [BONAP county map]	Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to northern Idaho; Europe, northern Africa, and the Middle East. [WildflowerSearch map] [BONAP county map]
Origin	Native	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	E. arvense, E. ×ferrissii, E. fluviatile, E. hyemale, E. laevigatum, E. ×litorale, E. ×mackaii, E. ×nelsonii, E. scirpoides, E. sylvaticum, E. telmateia, E. variegatum	E. arvense, E. ×ferrissii, E. fluviatile, E. hyemale, E. laevigatum, E. ×litorale, E. ×mackaii, E. ×nelsonii, E. palustre, E. scirpoides, E. sylvaticum, E. variegatum
Subordinate taxa		E. telmateia ssp. braunii
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, OR, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Rhizomatous annual, the stems not dimorphic, 2-8 dm. tall, with 5 to 10 deep grooves, the ridges smooth; stomates in a single, broad band in each furrow; central cavity less than 1/3 the diameter of the stem; sheathes green, 5-10 mm. long, with persistent teeth 3-7 mm. long, black or dark brown with broad, pale, papery margins.

Rhizomatous perennial, the stems dimorphic; sterile stems 5-30 dm. tall and 0.5-2 cm. thick, 20- to 40-ridged, the central cavity about 1/4 the diameter of the stem; stomates in 2 broad bands in the furrows; sheath 1-2.5 cm. long, with slender, tapered teeth 3-8 mm. long; fertile stems 2.5-6 dm. tall and 1.5-2 cm. thick; sheaths 2-5 cm. long, with 20-30 prominent teeth fused in groups of 2-4.

Leaves

Branches few and irregular to many and whorled, 5- to 6-angled, simple.

Branches only on sterile stems, whorled, ascending, 4- to 6-angled, solid, 1-2 mm. thick, sometimes again branched.

Spores

Cones pedunculate, blunt, deciduous.

Cone 4-7 cm. long.

Equisetum palustre

Equisetum telmateia

Habitat

Streambanks, wet meadows, and marshes, from the lowlands to moderate elevations in the mountains.

Moist areas in the lowlands.

Distribution

Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across the northern U.S. and Canada to the Atlantic Coast; circumboreal.

[WildflowerSearch map]

[BONAP county map]

Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to northern Idaho; Europe, northern Africa, and the Middle East.

[WildflowerSearch map]

[BONAP county map]

Origin

Native

Conservation status

Not of concern

Sibling taxa