Il6 WAYSIDE AND WOODLAND FERNS. 



sheaths are white except at the upper and lower margins, 

 which are black. The teeth have slender blackish-brown tips 

 which fall off early. The cones are small, conical, with 

 pointed tops ; they are ripe in July and August. (Plates 1 24, 1 28.) 



The cross-section of the stem is much like that of the Wood 

 Horsetail, except that the large central space is quite circular, 

 that the outside grooves are narrower and more numerous, and 

 the alternating ridges consequently closer together. The 

 substance of the cylinder is perforated by large shield-shaped 

 cavities corresponding with the external grooves and, near the 

 inner margin, there is a series of small circular tubes. 



There is a var. moorei, found near the sea at Wicklow and 

 Wexford, which has annual stems, with loose sheaths, and 

 blunt teeth with white tips. 



The Rough Horsetail is a plant of marshy grounds and moist 

 banks, chiefly where sheltered by woods. Though a northern 

 species, its range in this country does not extend farther north 

 than Ross-shire and Morayshire ; southward its limits are 

 Hereford, Surrey, and Kent. In all this district its occurrence 

 is only local. In Ireland it is rare, and has only a few stations 

 recorded. It ascends to 1700 feet in Forfarshire. 



Dutch Rush is so called because the supplies for use in this 

 country are chiefly imported from Holland, where their growth 

 is encouraged along the canals, in consequence of their under- 

 ground rootstocks and roots helping materially to bind the 

 banks together. The " rush " part of this name is suggested 

 by its close superficial resemblance to the common rush. 

 From its use for scouring and polishing it also got the names of 

 Shave-grass, Scrub-grass, Shave-weed, Scouring Rush, Pewter 

 Wort, and Dishwashings. The Latin name is from hiemalis, 

 winterly, in allusion to the fact that the stems are still alive 

 in winter, when those of the other species are dead and 

 bleached. 



