268 COMMON CANADIAN WILD PLANTS. 



moist, and uncoil themselves when dry. The use of these 

 tentacles is doubtless to assist in the escape and dispersion 

 of the spores. 



The fertile stems will have almost withered away by the 

 time the sterile ones appear. The latter are of the same 

 thickness as the fertile ones, but they are very much taller 

 and are green in colour. Observe, also, the grooving of the 

 sterile stem, and the whorls of 4- angled branches produced 

 at the nodes. 



* Annual-stemmed, not surviving the winter. 



-f- Fruiting in spring, the fertile stems pale or brownish, and earlier 

 than the herbaceous sterile stems or brandies. 



1. E. arven'se, L. (COMMON HORSETAIL.) Fertile stems 

 not branching, 4-10 inches high. Sterile stems slender, 

 taller, with many 4-angular green branches. Moist sandy 

 or gravelly soil, common. 



2. E. praten'se, Ehrh. Stems more slender, with 3-sided 

 simple brandies shorter than in E. arvense. Stem-sheaths 

 with short, ovate-lanceolate teeth (those of the branches 

 3-toothed.J The fertile stems produce branches, when older, 

 except at the top, which perishes after fructification. Low 

 meadows, Atl. Prov. and northward. 



3. E. Sylvat'ieum, L. Fertile stems branching. Branches 

 compound, with loose sheaths, those of the stem having 8-14 

 somewhat blunt teeth, while those of the branches have 4-5 

 (of the branchlets 3) lance-pointed diverging teeth. Top 

 withering away after fructification. Damp shady places, 

 Atl. Prov. and northward. 



t- -*- Fruiting in summer . Stems all similar, or the fertile contempor- 

 aneous with the sterile ones. 



4. E. palus'tre, L. Stems 10-18 inches high, slender, 

 very deeply 5-9-grooved, the lance-awl-shaped teeth whitish- 

 margined. Atl. Prov. and northward. 



5. E. limO'SUm, L. Stem 2-5 feet high, sHghtJy many- 

 furrowed. Sheaths appressed, with 10-22 dark-brown acute 

 snort rigid teeth. In shallow water. 



