DIOKSOUIEiE. XCTU. 



ooriaoeoue, distinct from tlie sutstanee of the frond ; the outer 



valve larger oucullate, the inner operculiform. Veins forked or 



piilnate from a central costa ; vermles free. 



Fronds large, decompound. Ehizome thick, short, decumbent, 



or erect. — This genus, like JHcTcsouia, has two-valved indusia; 



but in the present, the texture of the two valves is alike, and 



evidently different from that of the irond, on the extreme 



margin of which they are borne. 

 Ex. : C. Barometz, J. Sm. I C. assamica, Sook. 



C. Schiedei, Sckleeh. C. Chamissoi, Xlfs, 



C. glaucum, Mk. and Am. [ C. Menziesii, Mook. 



(b) Indimmn cup-shaped, reflexed. 



186. DEN"NST.a3DTIA, Sernhardi, Schrad.Jonrn. 1800, 

 ii. 124, t. 1, f. 3. 



DiCKaoNiA, Xaulfit^s ; Freal ; SiTOBOLluTi, Desoaux i Patania, PrcaZ ; 

 SiTOLOBlTTM, J. Smith; Aj3'ECTXn£, Link ; Depaei^ sp.t Hooker; PoLT- 

 PODII Sp., Auct ; CYATHEiE Bp., Auct; TEICHOMAIflS Sp., Auct. ; NepH- 

 BODII sp,, Auct. 



Sort involucrately-indusiate, globose, marginal, reflexedj the 

 reoeptacles small punctiform, terminal. Indtisium cupuliform 

 or pateriform, sub-membranaceous, the special and accessory 

 valves nearly equal, and coalescing into an almost entire, rarely 

 sub-bilabiate, reflexed cup. Veins pinnate, from a central costa ; 

 venules simple or forked, free. 



IVonds herbaceous, bi-pinnate or decompound; the sori ex- 

 serted within the cup-shaped involucriform indusia, and reflexed. 

 Khizome creeping. — A group quite distinct in habit from Dick- 

 sonia, and also differing in the sori being seated within cup- 

 shaped iudusia, which are almost or quite entire, instead of 

 distinctly two-valved. The cup, which is formed by the conflu- 

 ence of the special and accessory indusia, is sometimes, but 

 rarely, slightly notched at the sides when this confluence is not 

 quite perfect; these instances showing its affinity with 2)Jcfeo»M. 



Ex. : D, pimctilobu]a(Aspidium,5'a'.) 

 D. rubigino8a(Dicksonia,,Z^s, 

 D. deltoidea(Dicksoiua,SboZ;.) 

 D. adiantoides (Dickson. MS.) 

 J>. nitidula (Dicksonia, JS^ze.J 



D. cieutaria (Dicksonia, Sw.J 

 J). apiifoUa (Dickaonia, Svi.) 

 J), coiicmna (Davallia, Fr.J 

 D, macrophylla (Dicksonia, DeavJ 

 D. cuneata (Sitoiobiupi, J, Siji.J 



P. moluccana (Dioksonia, Bl.J D. Zippeliana (Dicksonia, Zie.J 



i3 



