﻿84. ATHYRIUM. 427 



x.x.Indusium not reniform. (3c} A. Copelandi. 



:)(i.if. Fully developed fronds larger, more than iO c.M. broad. 



(4) A macrocarpura. 

 f.^. Lower pinnae reduced. (5) A. acrostichoides. 



b.b. At least the lower pinnae pinnate to 2-pinnate. (') 

 c. Fronds small, under 15 c.M. long. (^) 



§. Rhizome creeping, often intertwined. (6) A. hyalostegium. 

 §.§. Rhizome short, erect. 



>K. Fronds + as broad as long. (7) A. Loheri. 



:^.^. Fronds ± 2 )<^ as long as broad. (8) A. Sarasinorum. 

 c.c. Fronds larger, more than 15 c.M. long when fully developed. 

 d. Teeth of the segments finely aristate, retroflexed. 



(9) A. arislulatum. 

 d.d. Teeth whether or not aristate, not retroflexed. 



e. Lower or costal sori often horseshoe-shaped or hamato-reniform. 

 X. Texture herbaceous. (10) A. solenopteris. 



x.x. Texture coriaceous. (11) A. drepanopterum. 



e.e. Largest sori hamato-recurvale at the apex only. 



(12) A. nitidulum. 



e.e.e. Soti straight or slightly curved, the lower sometimes 



double. 



f. Midribs, of the leaflets beset with distant, subulate, 



spine-like appendices on the upper side. Fronds + 



20—60 c.M. long. 



*. Fronds to 30 c.M. long, to 12 c.M. broad. 



Pinnae spreading. (13) A. gymnogrammoides. 



^.^. Fronds 30—60 c.M. long, 12 c.M. broad or 



broader. Pinnae erec to-patent. (14) A. nigripes. 



f.f. Appendices wanting or indislincl. Fronds 60 — 200 



c.M. long in the fully developed plants. 



g. Tertiary segments elliptico-rhomboidal, the base 



narrowed or ± decurrent. (15) A. umbrosum. 



tf.g. Tertiary segments linear-oblong, the base not 



narrowed, not decurrent. (16) A. silvaticum. 



(') See also A. inacrocarp<ie.im, Bedd. 

 (*) See also A. arlstulatum, Copel. 



