3S2 45a. pteris. 



Arrangement of the sections and groups. 



$1. EUPTERIS. Veins free. 



a. Pinnatifidae. Fronds pinnalifid throughout, at hest pinnate 

 at the very base. 



b. Piunatae. Fronds 5-foliate or pinnate, the lowest pinnae simple, 

 or forked with 2 — 3 undivided segments in tlie barren fronds. 



c. Conipositae. Fronds o-foliate or pinnate, the lowest pinnae at 

 least pinnatifid in the barren fronds. 



4:. Blplnnatlfldae. Fronds not 3- or 5-partite; lowest pinnae not 

 much longer than the next -higher ones and similarly pinnaliiid 

 or pinnate, with the lowest segments on the lower side not 

 rarely elongate and divided again. 

 >tc.*. Partltae. Fronds 3- or 5-partite; lateral branches nearly 

 as long as the central one and similarly 2-pinnatifid, with 

 the lowest segments on the lower side not rarely elongate and 

 divided again. 

 §2. CAMPTERIA. Veins slightly anastomosing, forming 1 single row of costal 



areolae on each side, otherwise free. 

 § 3. LITOBROCHIA. Veins anastomosing more copiously. 



Key to the sections and groups. 



Veins free. § 1. EUPTERIS. 



h. Fronds pinnatifid, at best pinnate at the very base. 



§ 1, a. Pinnatifidae. 

 b.b. Fronds 3-foliate, pinnate or more compoundly divided. 



c. Lower primary segments simple, or forked at the base with 

 2 — 3 undivided secondary segments in the barren fronds. 



§ 1, h. Pinnatae. 

 Lower primary segments at least pinnatifid in the barren fronds 

 ^ § 1, t- Coinpositae. 



d. Fronds not 3- or 5-partite, i. e. the lowest pinnae not 

 much longer than and similarly pinnatifid or pinnate as 

 the next higher ones, but not rarely forked at the base 

 with similarly divided branches, § 1, c*. Blpinnatlfldae. 

 d.d. Fronds 3- or 5-partite, i. e. the fronds divided into 3 or 



c.c 



