﻿22."'' DRYOPTERIS. 175 



veinlet springing from the top, free or joined in the angle of the next 

 superior anastomosing veins, which often form 1 or more rows of regular, 

 rhomhoidal areolae between the costal ones and the margin. Segments mostly 

 equal-sided or nearly so; surfaces often + hairy; texture commonly herba- 

 ceous. — The species are difficult of determination unless the whole stipe 

 and the rhizome are present; the frond only is of little value. 

 Tropical and extra-tropical. 



Arrangement of the sections. 



§1. LASTRAEA. Veins free. Indusium reniform. Hk. Bk., Syn. Fil., tab. V, 



fig. 44, c — d. 

 § 2. NEPHRODIUM. Veins anastomosing. Indusium reniform. Hk. Bk., 1. c, 



fig. 44, a — b. 

 § 3. CYCLOSORUS. Like % 2, but the indusium pellate, and round or cordate. 



§ 1. LASTRAEA. 



a. Fronds pinnate. Pinnae entire or lohed less than ^j^-way down to the costa. 

 >|c. Fronds sid)sessile. Pinnae entire or slightly erenale. (1) D. Warbui'gii. 

 ^.)ic. Fronds moderately long-stalked. Pinnae lohed '/^ — ^j^-ivay down. 



{1) D. birtipes. 

 «.«. Fronds pinnate. Pinnae cut more than ^j^-way down to quite to the costa. 

 Secondary segments entire or crenate to repand ('). 

 J. Central ribs of the lobes pinnate; veins simple. 



2. Lower pinnae slightly, if at all, reduced, not dwindling doivn into 

 mere auricles. 



3. Fronds small, under iO c.M. long (^). (3) D. grammitoides. 

 3.3. Fronds more than iO c.M. long. 



■J. Texture + ehartaceous or coriaceous. 

 5. Fronds under 75 c.M. long. 



e. Surfaces naked, at best pubescent on the costae. 

 v. Rachis naked ('). 



(') See also D. phegopferoidea, C. Chr. 

 (^) See also D. diversifolia, v. A. v. R. 

 (') See also D. pectinata, v. A. v. R, 



