86 HISTORY or BRITISH FERNS. 



naked, and gramme, a line ; alluding to the lines of spore- 

 cases, without covering membranes. 



Gymnogramma leptophylla, Desvaiix. 



The Slender Gymnogram. (Plate XXII. fig. 1.) 



This is a small Fern, of short duration, springing up 

 from the spores in the autumn of each year, attaining 

 maturity early in the following summer, and afterwards 

 quickly drying up and disappearing. Each plant consists 

 of a tuft of about half a dozen fronds, of which the earlier 

 are short and fan-shaped, divided only into two or three 

 lobes ; succeeding ones grow an inch or two in length, and 

 become pinnate, with obliquely fan- shaped three-lobed 

 pinnsB ; and finally others appear taller and more erect in 

 growth, and more abundantly fertile. These more perfect 

 fronds, the latest produced by the plant, are from three to 

 six inches high, ovate in outline, and two or three times 

 pinnate. The pinnae are alternate, ovate, with alternate 

 pinnules. The ultimate pinnules are roundish wedge- 

 shaped, three-lobed at the apex, the lobes rather distinct, 

 and usually notched at the end. The veins in each pin- 

 nule become branched, so that one of the small veins 

 proceeds towards each of the teeth into which the pinnule 



