81 



turbing the roots, and afterwards keeping the grass around well 

 trimmed to prevent overgrowth. The plants removed, with a 

 small portion of soil only, at the period of fructification seldom 

 live beyond the following year. The turf should be planted in 

 an exposed situation and where water cannot become stagnant 

 around it. 



Genus 18. OPHIOGLOSSUM. 



GEN. CHAR. Fructification arranged on the margins of a con- 

 tracted simple frond, forming a flattened stalked spike. Thecse 

 sessile, connate in two rows, opaque, opening transversely 

 with two valves. 



The aspect of the European species warrants the generic name, 

 from o<f)i<;, a serpent, and <y\(aa<ra, a tongue. 



The species, few in number as at present known, are chiefly 

 natives of warm climates. 



OPHIOGLOSSUM VULGATUM. Common Adder's-tongue. TAB. 

 XLVI. 



Barren frond ovate, obtuse, spathe-like. Fertile frond club- 

 shaped, springing apparently from the common rachis. 



Ophioglossum vulgatum, Linnaeus. E. B. 108. Generally 

 adopted. 



Though local in its distribution, and more frequent in England 

 than in other parts of the kingdom, the Adder's-tongue is gene- 

 rally abundant in those meadows and pastures in which it has 

 once settled, sometimes even prevailing to such an extent as to 

 become injurious to the grass. The situations it prefers are rarely 

 those which foster the Moonwort, the latter requiring a dry, while 

 the present plant flourishes best in a moist soil. The whole plant 

 is succulent and much resembles Botrychium in habit, and in the 

 development of its double frond, but differs in the production of 

 the new plant externally instead of within the base of the old one, 

 a circumstance illustrated in our figure. The height varies accord- 

 ing to the luxuriance of the surrounding vegetation from two or 

 three inches to a foot. The barren frond, of a pale yellowish- 

 green, invests the rachis of the fertile one as the spathe of the 

 Arum does its fructification ; its form is ovate varying to ovate- 

 lanceolate, more or less obtuse : the venation is more complicated 

 than is usual in the fern family, anastomosing and forming an 

 irregular network. The thecae are imbedded in two parallel series 

 on the margins of the club-like termination of the inner frond, to 



L 



