Burke: Equisetum hyemale vs. Equisetum ×ferrissii

	Equisetum hyemale	Equisetum ×ferrissii
	scouringrush horsetail , common scouring-rush	Ferriss' scouring rush
Habit	Rhizomatous, evergreen perennial, the stems all alike, mostly unbranched, 2-15 dm. tall and 4-14 mm. thick, with 18-40 ridges, each ridge with 2 rows of tubercles; central cavity at least 3/4 the diameter of the stem; stomates in 2 lines in each furrow; sheaths 5-15 mm. long, black banded at the tip and also with a lower black band, ashy- gray between the black bands, green below the lower band.	Annual to perennial herb, 20-180 cm; sheath 7-17 mm, 3-12 mm broad, commonly with dark bands; teeth 14-32, deciduous or persistent.
Leaves	None	None
Spores	Cones short-pedunculate, 1-2.5 cm. long, sharp pointed.	Cone tip pointed; spores white and mishappen.

	Equisetum hyemale	Equisetum ×ferrissii
Habitat	Moist to wet areas, lowlands to moderate elevations in the mountains	Dry to wet, often disturbed areas, including gravelly roadsides.
Distribution	Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]	Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east across most of North America to the Atlantic Coast. [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. laevigatum, E. ×litorale, E. ×mackaii, E. ×nelsonii, E. palustre, E. scirpoides, E. sylvaticum, E. telmateia, E. variegatum	E. arvense, E. fluviatile, E. hyemale, E. laevigatum, E. ×litorale, E. ×mackaii, E. ×nelsonii, E. palustre, E. scirpoides, E. sylvaticum, E. telmateia, E. variegatum
Subordinate taxa	E. hyemale ssp. affine
Web links	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	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

Equisetum ×ferrissii

scouringrush horsetail , common scouring-rush

Ferriss' scouring rush

Habit

Rhizomatous, evergreen perennial, the stems all alike, mostly unbranched, 2-15 dm. tall and 4-14 mm. thick, with 18-40 ridges, each ridge with 2 rows of tubercles; central cavity at least 3/4 the diameter of the stem; stomates in 2 lines in each furrow; sheaths 5-15 mm. long, black banded at the tip and also with a lower black band, ashy- gray between the black bands, green below the lower band.

Annual to perennial herb, 20-180 cm; sheath 7-17 mm, 3-12 mm broad, commonly with dark bands; teeth 14-32, deciduous or persistent.

Leaves

None

Spores

Cones short-pedunculate, 1-2.5 cm. long, sharp pointed.

Cone tip pointed; spores white and mishappen.

Equisetum hyemale

Equisetum ×ferrissii

Habitat

Moist to wet areas, lowlands to moderate elevations in the mountains

Dry to wet, often disturbed areas, including gravelly roadsides.

Distribution

Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.

[WildflowerSearch map]

[BONAP county map]

Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east across most of North America to the Atlantic Coast.

[WildflowerSearch map]

[BONAP county map]

Origin

Native

Conservation status

Not of concern

Sibling taxa