DICKSONlEai. XCT. 



§ 22 DlCKSONIB^. 

 (a) Indiisittm distinct^/ tvio-vahed. 



132. DICKSONIA, L'Seritier, Sertmi Anglieim 30. 



'BA.TjiyiT.VTS.j Kaulfuss : JPresl; Citlciia, PreaJ; Lsptopletteia, Tresis 

 Ctstodittm, J". SuMth; DavaTiLLS sp.j^Mcrc.; ClsOTll Bp., Auct.; MlCEO- 

 LEPi^ sp., Auct. ; PATANLffl sp., And,; N^PHEOLEpiDls sp., Meitenius. 



Son involucrately-indusiate, globose or eliort transTerae ob- 

 long, marginal, more or less reflexed ; tbe receptacles globose or 

 transverse oblong, terminal, Indmsimm coriaceous, double i.e. 

 two- vaWed ; the outer or accessory yalve formed of a more or 

 less attenuated lobule of tie frond, cueuUate, sometimes equalling 

 in size, but more frequently larger than the inner yalve or proper 

 indusium, which latter, when smaller, is less eonTei than the 

 outer. Veiiis simple forked or pinnate, from a central costa; 

 vemdes free. 



Fronds coriaceous, usually large decompound, sometimes 

 pinnate, the fertile portions appearing somewhat contracted. 

 Khizome thick, short, erect, or arborescent; sometimes (in D. 

 GulcitaJ decumbent, criniferous. — A genus of noble ferns, includ- 

 ing several arborescent species. It is distinguished from Denn- 

 st<BdUa by the two-valved, not entire cup-shaped, indusium ; and 

 from Cibotiwm by the more or less herbaceous texture of the 

 outer valve of the indusiam, which in Diclcsonia, is but a par- 

 tially changed lobule of the frond. 



Ex. : D, arboreBcens, Ij Merit, 

 D, squarrosa, Sw. 

 D. coniifoUa, Sook, 

 D. dabia, &aud. 

 D, sorblfolia, Sm. 



D, autarctica, Labill. 

 D. Sellowiana, B^ook, 

 D. Culoita, L'Serit. 

 D, Plumieri, Hook. 

 D, abrupta, Bory. 



183. DICLISODON", Jf. (from cii/cZu, double or two-valved, 

 and odon.J 



Sori involucrately-indusiate, rotundate, extra-marginal, i.e., 

 occupying small projecting marginal teeth ; the receptacles punc- 

 tiform, terminal. Indmsium extrorse-marginal, two-valved, flat ; 

 the outer or accessory valve a small rounded herbaceous project- 

 ing lobe of the frond; the inner valve, or proper indusium, 

 membranaceous, larger than the lobe, distinctly reniform affixed 



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