12 EQUISETACEAE. 



the sterile; fertile stems 10-20 cm. tall, simple, terete, bearing about four loose 

 scarious distant sheaths, these whitish with about 12 brownish acuminate 

 teeth; sterile stems pale green, 1040 cm. tall, marked with 6-19 furrows, with 

 numerous whorls of mostly simple solid branches, these 4-angled or r?rely 

 3-angled, the sheaths with as many teeth; spike 2-3 cm. long. 



Common in low ground. In rare cases fruiting spikes are found on green 

 branched plants. 



Equisetum telmateia Ehrh. Sterile stems stout, 60-120 cm. high, 20-40- 

 furrowed, with numerous whorls of long spreading 4 or 5-angled branches; 

 fertile stems 30-40 cm. high, pale-brown, the sheaths loose, often longer than 

 the internodes and deeply 20-30-toothed; spikes stout, 3-5 cm. long. 



Very common in moist soil and difficult to eradicate. Rarely spikes are 

 found on the green branched plants. 



Equisetum fluviatile L. Pipes. Stems 60-90 cm. high, rather soft, 

 smooth, simple or with few branches; central cavity of the stem large; air- 

 cavities under the grooves wanting; sheaths closely appressed, the teeth rigid 

 and acute; branches 4-6-angled, hollow, not wing-angled. 



In shallow water at the margins of lakes and ponds. 



Equisetum litorale Kiihlewcin. Stems 30-90 cm. high, simple or with few 

 or many branches; air cavities under the grooves present; sheaths loose, 

 especially the upper, the teeth not rigid, membranous at margin, acute; 

 branches 3-5-wing-angled, the smaller solid. 



Shawnigan Lake, Vancouver Island, Macoun; Agassiz, British Columbia, 

 Macoun. The spores of this species are said usually to be abortive and the 

 elaters wanting. These facts combined with the erratic occurences of the 

 plant lead to the suspicion that it is a hybrid. 



Equisetum ramosissimum Desf. Stems 6-26-grooved; sheaths dilated, the 

 leaves more or less distinct, each with 3-4 ridges which do not extend into the 

 teeth; branches 4-angled. 



Shawnigan Lake, Vancouver Island, Macoun. 



Equisetum hyemale L. Scouring Rush. Aerial stems evergreen, all alike, 

 40-120 cm. tall, 5-20 mm. thick, marked with 20-48 furrows; ridges roughened 

 usually with a single series of siliceous tubercles; sheath short, commonly 

 marked with a black girdle at the base and another at the base of the early- 

 falling teeth; spike nearly sessile in the uppermost sheath, 2-3 cm. long, tipped 

 with a rigid point. 



Common and variable. Several subspecies have been described but they 

 are not clearly separable. 



Equisetum variegatum Schlcich. Stems slender, tufted, ascending, 15-40 

 cm. high, each 5-10-furrowed; sheaths loose, green below, black above, with 

 5-10 bristle-tipped white-margined teeth; central cavity of stem small. 



Vancouver Island, Macoun, and probably farther south as it occurs in 

 Klickitat County in eastern Washington. 



Equisetum scirpoides Michx. Stems tufted, very slender, flcxuous, 6-15 

 cm. long, each 6-furrowed; sheaths with 3 bristle-tipped teeth; central cavity 

 of stem wanting. 



Hastings, British Columbia, Macoun, and probably to be found in our 

 limits. 



Class III. LYCOPODINEAE. 



Plant moss-like; stems branched, solid, with numerous 

 small leaves; sporangia solitary in the axils of the leaves or 

 on their upper surface. 



