170 19. POLYSTICHUU. 



¥ar. Sarasinoi'iiin : Small form. Fronds + 20 c.M. long: seg- 

 ments short, deeply incised, bluntish or short-acuminate, not aristate. 



Malaya; Polynesia, Australia, Japan, China, North. India, Natal; — var. 

 Sarasinorum: Celebes. 



30. DlDYMOCHLi^AJEIV^^, negvaux. 



Sori oblong, terminal on the veins, but not marginal. Indusium the 

 onmo shape of the sorus, fixed by its longitudinal axis, opening on all sides. 



Rhizome erect. Stipes not articulate to the rhizome. Fronds 2-pinnate. 

 LeaQets unequal-sided, subdimidiate, the basipetal half being obliquely cut away; 

 veins free. Hk. Bk, Syn Fil., tab, IV, fig. 42: Diels, in Engl A; Prantl., Nat. 

 I'fl.Fam., I*, fig. 95. 



Pantropical. 



* D. lunulata, J>e«r., Rac, Flor. Btz., I, 197; Bedd., Ferns Br.I., 

 I, tab. XV; Hk,, Gard. Ferns, tab. XVII: D. sinuosa, Desv., Bau. & Hk., Gen 

 Fil., tab. Vni; D. truncatula, J. Sm., Journ. of Bot., IV, 196; C. Ghr., Ind. 

 Fil; Adiantum lunulatum, HoulL, (oldest name). 



Caudex erect, subarborescent. Stipes densely tufted, several d.M. long, 

 paleaceous. Fronds 60 — 180 c.M. long, 50 — 60 c.M. broad, 2-pinnate, oblong 

 to lanceolate: Pinnae numerous, sessile or short-stalked, erecto-patent, linear, 

 acuminate, 2 — 4 c.M. or more broad. Pinnulae numerous, close, articulate, 

 subrhomboidal, about half as broad as long, the upper base broadly and the 

 lower narrowly cuneate, the edge entire or slightly sinuate. Texture sub- 

 coriaceous; main rachis scaly, the scales narrow, fimbriate; secondary rachises 

 slightly scaly, sometimes hairy ; upper surface slightly covered with subulate 

 bristles. Sori 2 — 6 to a pinnula. 



Pantropical. 



31. I»LEOCIVEMI^, JPre*l. 



Sori roundish, medial or terminal on the free veins or veinlets, rarely on 

 the netted veins. ludusium reniform, attached by the sinus, rarely round and 

 peltate. 



Rhizome generally erect. Stipes not articulate to the rhizome. Fronds of- 

 ten ample and compound; lower veins of contiguous groups united and those 



