154 PTERIS. 



AUosorus farinosus, Kze. in Schk. Fil. Snpp/. ii.p. 5. t. 103, 

 is Gymnogramme ornithopteris, Klotzsch in Linn. xx. p. 413. 



10. Pteris, Linn., Sw., and Willd. (for the most part). 



(Hook. Gen. Fil. tab. LXIV. A.) Heterophlel)ium, Fee. 

 Campteria, Pi'esl (Hook. Gen. Fil. tab. LXV. A). Lito- 

 brochia, Pr. (Hook. Gen. Fil. tab. LXV. B. f. 6). Dory- 

 opteris, /. Sm. Amphiblestra, Pr. (Hook. Gen. Fil. tab. 

 CXX. C.) 



Sori marginal, linear, continuous, occupying a slender fili- 

 form receptacle in the axis of the involucre. Involucre mar- 

 ginal, generally narrow, continuous, formed of the dilated, 

 more or less changed and usually membranaceous margin 

 of the frond, at first revolute, at length often spreading in 

 age, so as to expose the line of fructification. — Ferns tropical 

 or subtropical and of temperate regions. Root sometimes 

 composed of densely tufted fibres from the sivollen base of the 

 united stipites, with no perceptible caudex ; at other times there 

 is a distinct caudex more or less elongated, creeping and scaly. 

 Fronds rarely simple and small, more or less lobed or palmate, 

 generally compound and often of a very large size (1 to 5-6 

 and more feet), mostly of a tender and submembranaceous tex- 

 ture and of a bright green, sometimes coriaceous and very 

 opaque. Veins generally very distinct, simple, sometimes fla- 

 bellate, or pinnate, with the veinlets simple or more or less 

 anastomosing .- this tendency to become reticulated is sometimes 

 confined to the margins of the pinnules (Heterophlebium, Foe), 

 or the union of the veins takes place more or less near to the 

 costa, where they form a series of large areoles (Campteria, 

 Pr.), or the entire frond is reticulated with areoles various in 

 size and form (Litobrochia, Pr., and Doryopteris, J. Sm.), or 

 lastly the areoles are appendiculate (furnished with one or 

 more free veinlets), clavate at their apices (Amphiblestra, Pr.). 

 Stipes more or less elongated, and together with the rachis 

 frequently brown or stramineous, while those that have small 

 coriaceous and opaque fronds (Doryopteris, /. Sm.) and the 

 habit of Pellsea, are generally ebeneous, the bases often hairy 

 or scaly. 



It will be seen from the characters and the references above given, that I have 

 taken the bold step, and what many will consider a retrograde movement in 

 botany, in restoring almost entire the original Pteris of Linnjeus and Swartz and 



