Burke: Equisetum palustre vs. Equisetum scirpoides

	Equisetum palustre	Equisetum scirpoides
	marsh horsetail	sedgelike horsetail, dwarf scouring rush
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, evergreen perennial, the stems all alike, prostrate or ascending, firm, 0.7-2.5 dm. tall and 0.5-1 mm. thick, 6-grooved and angled, alternating grooves shallower and deeper; stomates in two rows in each principal furrow, sunken below the level of the epidermis; central cavity none; sheaths short and flaring, with a broad, black band above the green base; teeth of the sheath 3, thin and fragile, bristle-tipped, 1-2 mm. long.
Leaves	Branches few and irregular to many and whorled, 5- to 6-angled, simple.	Unbranched, or with a few long branches from near the base.
Spores	Cones pedunculate, blunt, deciduous.	Cone small, 3-5 mm. long, sub-sessile, sharp pointed.

	Equisetum palustre	Equisetum scirpoides
Habitat	Streambanks, wet meadows, and marshes, from the lowlands to moderate elevations in the mountains.	Moist, swampy places, especially in coniferous forests.
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 east of the Cascades crest in northeastern Washington; Alaska to Washington, east across the northern U.S.and Canada to the Atlantic Coast; circumboreal. [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. sylvaticum, E. telmateia, E. variegatum
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, 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

Equisetum scirpoides

marsh horsetail

sedgelike horsetail, dwarf scouring rush

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, evergreen perennial, the stems all alike, prostrate or ascending, firm, 0.7-2.5 dm. tall and 0.5-1 mm. thick, 6-grooved and angled, alternating grooves shallower and deeper; stomates in two rows in each principal furrow, sunken below the level of the epidermis; central cavity none; sheaths short and flaring, with a broad, black band above the green base; teeth of the sheath 3, thin and fragile, bristle-tipped, 1-2 mm. long.

Leaves

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

Unbranched, or with a few long branches from near the base.

Spores

Cones pedunculate, blunt, deciduous.

Cone small, 3-5 mm. long, sub-sessile, sharp pointed.

Equisetum palustre

Equisetum scirpoides

Habitat

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

Moist, swampy places, especially in coniferous forests.

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 east of the Cascades crest in northeastern Washington; Alaska to Washington, east across the northern U.S.and Canada to the Atlantic Coast; circumboreal.

[WildflowerSearch map]

[BONAP county map]

Origin

Native

Conservation status

Not of concern

Sibling taxa