— 70— 



debile as an astringent. Some species are used at times as fodder 

 for stock, mostly from lack of better material. Cows do not reject 

 arvense, but do not appear to relish it. Silvaticum is the prin- 

 cipal fodder of horses in some parts of Sweden, but is not 

 relished by cows. Fluviatile has been used as food for cows and 

 is reputed to induce an abundant flow of milk. L&vigatum is 

 used as hay in parts of Nebraska, according to Rydberg, and 

 litorale and fluviatile are cut along the borders of the Merrimac 

 at Amesbury, Mass., but evidently are not valued highly. 



Though of little use, the marestails of America are also free 

 from the charge of being pernicious. Fluviatile and litorale 

 border the shores of streams and slow brooks, the latter occa- 

 sionally appearing in damp pastures ; pratense, very pernicious 

 in fields of central Europe, is rarely collected here, as is palustre. 

 Silvaticum keeps to the shade of the woods or to field borders. 

 Only twice have I seen hyemale growing in cultivated fields, and 

 although it has grown among hoed crops in one locality for years, 

 it never appears to do any harm. The only species having a 

 tendency to become weeds are arvense and perhaps telmateia. 

 The former grows extensively in the gravel of railroad grades 

 and in damp fields among hoed crops, often covering the 

 ground. 



CLASSIFICATION. 



There are two well-marked groups of Equiseta sufficiently 

 well characterized to be classed as genera, though they have 

 always been treated as sub-genera. The first, Equisetum, has fruit 

 stems mostly different from the sterile, has stomata scattered in 

 the grooves, and habitually regular verticils of branches. The 

 stems are annual, usually perishing early in the season. The 

 second, Hippochcete, has the stems ail alike, evergreen, per- 

 sistent for three to four years, usually very rough with silex, 

 branched (in ours) only in case of injury to the main stock, or 

 where it has previously fruited. The branches are formed the 

 second or third year. The stomata are in regular lines, usually 

 one row on each side of a ridge. Arvense may be taken as a 

 type of the first, and hyemale of the second. 



The species of Equisetum are well characterized, while those 

 of Hippochccte appear in a measure to be geographical forms, the 

 little scirpoides of the north being connected with the great 

 giganteum of Mexico by a more or less continuous chain of in- 

 termediate species. It is often extremely difficult to determine 



