OregonFlora: Equisetum scirpoides vs. Equisetum laevigatum

	Equisetum scirpoides	Equisetum laevigatum
		smooth scouring rush
Sheaths		rectangular, 7–12 × 5–6 mm (uppermost sheath shorter); same color as stem and continuous with it; except for a terminal black band formed by the inturned persistent bases of the teeth; teeth earlydeciduous, articulated and campanulate.
Aerial stems		annual, monomorphic; up to 120 cm tall, usually simple, occasionally with a few hollow ascending branches, green; ribs 16–30, not furrowed; central cavity up to 75% of the stem diameter.
Branches		(when present) with a dark base; first internode very short.
Cones		shortly exserted from the terminal sheath or subsessile; blunt.
2n		=216.

	Equisetum scirpoides	Equisetum laevigatum
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion		Moist meadows, roadsides, and river banks. 50–2000 m. All ecoregions except Est. CA, ID, NV, WA; throughout North America. Native.
Source		Flora of Oregon, volume 1, page 79 Duncan Thomas
Sibling taxa	E. arvense, E. fluviatile, E. hyemale, E. laevigatum, E. palustre, E. telmateia, E. variegatum	E. arvense, E. fluviatile, E. hyemale, E. palustre, E. telmateia, E. variegatum
Synonyms		Equisetum funstonii, Equisetum kansanum
Web links	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	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 scirpoides

Equisetum laevigatum

smooth scouring rush

Sheaths

rectangular, 7–12 × 5–6 mm (uppermost sheath shorter); same color as stem and continuous with it; except for a terminal black band formed by the inturned persistent bases of the teeth;

teeth earlydeciduous, articulated and campanulate.

Aerial stems

annual, monomorphic; up to 120 cm tall, usually simple, occasionally with a few hollow ascending branches, green;

ribs 16–30, not furrowed; central cavity up to 75% of the stem diameter.

Branches

(when present) with a dark base; first internode very short.

Cones

shortly exserted from the terminal sheath or subsessile; blunt.

=216.