-riLICES. 



23 



Sori globose, placed in the sinuses of the 

 frond and covered by a pseudo- 

 involucre formed of the green in- 

 curved (but unchanged) tip of the 

 segments of the frond. Fronds 

 usually 6 in. to 3 ft. high 13. Hypolepis. 



Sori on the veins, at or near the tip, at 



first globose but afterwards continu- , 



ous round the margins, which are 



reflexed over them. Fronds usually 



under 6 in ... 14. Cheilanthes. 



Sori in a continuous line within the 

 margin ; involucre opening inwards, 

 at length recurved and exposing the 

 sori. Fronds pinnate 15. Pellsea. 



Sori continuous, marginal; involucre 

 membranous, recurved. Fronds 2- 

 or 3-pinnate 16. Pteris. 



Fertile and barren fronds dissimilar. Sori 

 linear, continuous, parallel with the 

 midrib and filling the segment; in- 

 volucre formed of the revolute mem- 

 branous margin 17. Lomaria. 



Family IV. ^ — Blechnete. Sori oblong or linear, on the hack of the 

 frond, pa/rallel toith and distant from the margin of tlie segments. 

 Involucre of the same shape as the sorus, opening towards the midrib. 

 (PI. II. fig. 9.) 



Sori on veins which form arches between 

 the midrib and margins of the seg- 

 ments 18. Doodia. 



Family V. — Aspleniese. Sori linear (or oblong), attached to the 

 veins, and placed obliquely to the midrib. 



Involucre membranous, fastened on one side 

 to the vein, opening along the outer 

 edge (PI. III. figs. 1 and 2.) ... 19. Asplenium. 



Family VI. — Aspidiese. Sori globose, on the bach of the frond. 

 Involucre globose or reniform, attached by a point at the centre or 

 sinus. (PI. III. figs. 3-5.) 



Involucre orbicular, fixed by the centre 20. Aspidium. 



Involucre cordate-reniform, fixed by the 

 sinus. Fronds pinnate or very com- 

 pound 21. Nephrodium. 



Involucre reniform, opening outwards, 

 and attached by a broad base. 

 Fronds pinnate 22. Nephrolepis. 



