

LIBKAKY 

 / YORK 

 C A I 



LIST OF SPECIES. 



EQUISETACE/E. 



EQUISETUM L. 



E. arvense L. Field Horsetail. Very common throughout in 

 any kind of soil. Fertile stems early in spring, brown in 

 color. Sterile, later, much different in appearance from 

 the others. This species when growing in thin, sandy soil, is 

 quite changed in appearance. Instead of an erect central 

 stem, it becomes nearly or quite prostrate. The so-called variety 

 campeslre is often found. In this the normally sterile fronds 

 bear small fruiting spikes at the summit. The fertile stems 

 occasionally have a few green branches at the bpse. Gray's 

 Manual says the rootstock occasionally bears tubers. 



E. sylvaticum L. Wood Horsetail. Abundant in moist wood- 

 lands. Sterile stems producing several very regular whorls of 

 branches, which are again branched. The most beautiful mem- 

 ber of the genus in our region. It thrives well in cultivation if 

 given shade and moisture. 



E. fluviatile L. Pipes. Swamp Horsetail. Plentiful on the 

 borders of lakes, streams and ditches, often in shallow water. 

 Stems frequently unbranched, but usually producing a few 

 Q*) straggling branches near the summit of the stem. So many 

 forms of this species occur, according as it is branched or un- 

 branched, that it often appears like another species. It is one 

 of the commonest of plants along the Susquehanna. (E. limo. 

 •»■• sum L. ) 



E. hyemale L. Scot rim; Rush. Shave Grass. Plentiful in low 

 woodlands, on the banks of streams, and other moist places. 

 Stems commonly unbranched, stiff, two feet or more high, per- 

 sisting through the winter. In winter the hollow stems are 



