﻿37. ADIANTUM. § 1. EU-ADIANTUM. C. POLYSOIUAE. 329 



the lower of which are branched again below a long terminal branch. Se- 

 condary branches ± 8 c.M. long or longer. Leaflets dimidiate, rhomboidal 

 (almost a parallelogram), sessile, numerous, close, 2 — 3 c.M. long, + 1 c.M. 

 broad, the upper and lower sides parallel, the apex bluntly rounded, the upper 

 and outer edge crenate, or lobed and serrate. Texture firm-membranaceous 

 or subcoriaceous ; rachises and surfaces naked; veins terminating in the ulti- 

 mate serratures. Sori numerous, placed in shallow hollows at the apices of 

 the lobes or crenations, 1 to each lobe, along the upper and sometimes also 

 the outer edge; capsules springing from the veins only. 

 Much cultivated. — Orig. loc. : Venezuela, Peru. 



a. 



% 1. EU-ADIANTUM. d. Cuneatae. 



Ultimate segments (lea/lets) articulate at the base; ultimate petioles distinctly 

 nodose at the apex. (18) A. tenerum. 



a.a. Ultimate segments (leaflets) not articulate at the base; ultimMe petioles not 

 nodose at the apex. 

 h. Leaflets with the outer edge entire or shallowly lobed. 



c. Sori rather numerous, typically 3 — 6, sometimes 2 to a leaflet. 

 d. Leaflets often dimidiate or trapezoidal, the terminal ones cuneale. 



(19a) A. neoguineense. 

 (196) A. opacum. 

 d.d. Leaflets cuneato-flabellaie to suborbicular. 



e. Sori in rather half-rounded hollows; sporangia springing 



from the veins and parenchyma. (20) A. aethiopicum. 



e.e. Sori in shallow hollows; sporangia springing from the 



veins only. (21) A. suborbiculare. 



C.C. Sori few, typically d — 2, sometimes 3 to a leaflet. 



(22) A. celebicum. 

 b.b. Leaflets with the outer edge rather deeply lobed. 



$. Lower leaflets of the pinnae overlapping the main rachis, adpressed 

 to the latter. 



•J>. Pinnae spreading. (25) A. concinnum. 



^••J-. Pinnae erecto-patent. (24) A. tinctum. 



§.§. Lower leaflets not overlapping the main rachis. 



