CHARACTERS OF TRIBES AND GENERA. 195 



99. DICTYOPTERIS, Presl, in part. (1836). 

 Polypodium, sp., auct., Hook., Sp. Fil. 



Vernation fasciculate, decumbent, or sub-erect. Fronds 

 coriaceous, deltoid, bipinnatifid or bipinnate, 3 to 4 feet 

 high, ultimate segments or pinnules sub-entire or sinuous- 

 pinnatifid, Feins costaeform, venules and veinlets anasto- 

 mosing (rarely few free, excurrent), forming oblique some- 

 what elongated areoles, the costal ones transversely 

 elongated. Receptacles medial or compital. Sori round 

 large, irregular or regular, or transversely one to two 

 serial, sometimes crowded near the margin, naked. 

 Type. Polypodium irregulare, Presl. 

 Illust. Fee, Gen. Fil., p. 267, t. 31, A, f . 2 ; J. Sm., 

 Fern, Brit, and For., fig. 62 ; Hook., Syn. Fil., t. 5, 

 fig. 48, 0. 



OBS. This genus consists of a few large compound- 

 fronded Ferns, natives of the East Indies, Malay, and Philip- 

 Dine Islands, and one is found in Tropical West Africa. In 

 general habit they resemble the preceding genus, as also 

 Aspidium, as here restricted, but differing in having a 

 more simple anastomose venation, and from the latter in 

 being destitute of an indusium; but the latter character 

 is probably not always normal, for in cultivated plants of 

 D. irregulare a very minute indusium was observed in the 

 early stage of the sori, but as the sori increased in size 

 it left no trace of its having been present. 



Ex. D. irregularis, Pr. (v v.) ; D. megalocarpa (Hook.) 

 D. pteroides, Pr. ; D. Cumingiana, Pr., in Epim. Bot. (v v.) 

 (D. macrodonta, J. Sm., Gen. Fil., 1841, and Ferns, Brit, 

 and For.) ; D. Camerooniana (Hook.) (v v.). 



OBS. In the herbarium specimens it is difficult to 

 separate the many forms as distinct species, but cultivated 



