80 



latter it occurs from Cork to Antrim. Dry exposed heaths and 

 commons, and elevated rocky pastures are the likely and frequent 

 habitats, but it is liable to be overlooked, in consequence of the 

 small size and frequent cropping of the fructifying frond by cattle. 

 The habit of this plant is totally different from that of Osmunda 

 and all of the soriferous ferns : it has no true rhizoma, but the 

 growing part or caudex is very little elongated below the surface 

 of the soil, sending out a few succulent and brittle roots that 

 extend more or less horizontally : the upward growth is from a 

 lengthened bud invested by the membranaceous bases of previously 

 developed fronds. The perfect plant consists of a single pinnated 

 barren frond, through the sheathing lower part of whose rachis 

 rises a second, modified, and bearing the fructification. The suc- 

 culency of the recent pseudo-stem thus formed, renders its positive 

 structure obscure, and has occasioned it to be sometimes described 

 as homogeneous, and the frond to be considered branched. The 

 pseudo-stem is hollow ; and at the base, the fronds of the following 

 year may be traced by dissection, more or less perfectly formed, 

 and often, the rudimentary bud of the year succeeding within the 

 latter; the position of the barren and fertile fronds being reversed 

 in the nuccessional development. The pinna? are opposite, num- 

 bering from three or four to seven pairs, of a glaucous green hue, 

 smooth, crenated on the margin, and occasionally more or less 

 lobed, acquiring, in the latter case, a fan-shape instead of the lunate 

 or crescent-form which confers the specific name. The thecae are 

 comparatively large, and, though at first sight apparently crowded, 

 are really disposed in two regular series upon the divisions of the 

 panicle-like rachis, and directed towards the upper or inner face of 

 the modified frond ; their texture is more dense than in Osmunda, 

 and presents no trace of the regular cellular reticulations which 

 character the membranaceous ones of that genus : dehiscence takes 

 place along an elevated vertical line formed by the junction of the 

 margins of the valves. The fertile frond, which is the taller of 

 the two, rises to the height of five or six inches, and is in perfec- 

 tion about the time of the hay-harvest ; soon after which the plant 

 begins to decay. 



Specimens are occasionally met with bearing more than one 

 barren or fertile frond; others with the pmnse-bearing theca? on 

 their margins ; and sometimes the pinna? are so much divided as 

 to render the frond almost bipinnate. Cei-tain variations of the 

 latter form may have induced some botanists to consider one or 

 other of the continental species, B. rutaceum, or jB. matricarioides, 

 to belong to Britain, a circumstance not at all unlikely, but re- 

 quiring surer evidence than we at present possess. 



The only mode of ensuiing the growth of the Moonwort in the 

 fern garden, is by removing the turf containing it without dis- 



