80 American Fern Journal 



stems green, slender, 4-24 in. high, 6-19-furrowed, with 

 many whorls of branches; branches long, jointed, 3-4 

 angled, solid, their sheaths 4-toothed, stomates in two 



rows in each furrow; central stem hollow f-$ the 

 diameter of the stem. Fertile stems appearing very 

 early, before the sterile, 4-12 in. high, unbranched, of 

 short duration, light brown; their sheaths whitish, end- 

 ing in about 12 acuminate teeth. — In sandy soil specially 

 along railroad embankments, in meadows and in cul- 

 tivated fields. Alaska to Greenland, south to California 

 and New England; Europe; Asia. 



2. Equisetum telmateia Ehrh. (Plate 4, Figs. 5, 6.) 



Giant Horse-tail. 



Stems abov.- ground are annual, of two kinds. Sterile 

 stems ivory-white or greenish, stout, 2-8 ft. high, 20- 

 40-furrowed; their branches very numerous, erect to 

 spreading, simple, 4-5-angled, the ridges rough and sul- 

 cate, the lower joint shorter than the leaf-sheath of the 

 stem. Fertile stems 10-15 in. high, short-lived, white, 

 many-f urrowe< 1 ; leaf-sheaths loose, brownish, elongated, 

 deeply 20-30-toothed.— In all kinds of soil, much in 

 swamps and on railroad embankment-. British Colum- 

 bia to California; Kurope. 



3. Equisetum palu^tre L. (Plate 4, Fig. 11.) 



Marsh Horse-tail. 



Stems above ground are annual, branched, slender, all 

 alike, 10-20 in. high, deeply 5- 9-furrowed; the furrows 



separated by narrow, wing-like, roughish ridges; stem- 



eheaths U» e, toothed; their teeth about s. lance- to awl- 

 shaped, whitish, marginal; branches few, in a whorl, 

 simple, 4-7-angled, hollow; branch-sheaths 



toothed.— Alaska to Nova Scotia, south to Washington 



and Xew York; Europe. 



nios 



