(JHElLANTHIiS. 75 



4. Cheilanthes, Sw. 



(Hook. Gen. Fil. tab. CVI. B.) Cbeilanthis Sp., Sw. ct 

 Auct. Adianti, Allosori, Pteridis, Cassebeerse, Nutholenw, 

 Hj'polepidis Sp., Auct. 



Sori subglobose, marginal, small, generally upon a lobule 

 or loolh of the margin of Uie frond which becomes veflexed. 

 Involucre usually at first punctiform, semiorbicular or subre- 

 niforra or oblong, formed of a reflexed tooth or lobule and 

 more or less of the texture of the frond, or membranaceous 

 and diaphanous, entire or jagged or toothed or ciliated, more 

 or less confluent, so as often to be continuous; sometimes its 

 situation is a little intramarginal. — Tropical or extratropical 

 mostli/ small Ferns, inliahiting dry rocky places, with a tufted 

 root or rather short creepimj rhizoma or caudex. Fronds 

 tufted more or less, often densely so, membranaceous, gla- 

 brous, or hairy, woolly or more or less scaly, never sim- 

 ple, more or less compound, rarely sim2)ly pinnate, bi- 

 tripinnate or variously pinnaiifid, pinnules and segments 

 generally small, their margins recurved in fructification. 

 Stipites and principal rachises usually ebeneous (dark 

 purple-black) and glossy. Veinlets forked, free, conspi- 

 cuous or obsolete, their apex bearing a single sorus. 



Vain is the attempt to form any definite character which shall decide 

 the proper limits of this Genus. A glance at the above synonyms will suf- 

 fice to show the views that different authors entertain respecting; it. From 

 Adiantum indeed the habit is very different, as well as the position of the 

 sori upon the involucre in Adiantum ; on the margin of the frond in Chei- 

 lanthes, (%ejXoj, margin, and avQcg, a flower). In separating Hi/polepis 

 from it, I have been induced to refer to that Genus (by no means generally 

 adopted), species which many would retain, and perhaps justly, in Cheilan- 

 thes. But a much greater difficulty exists in drawing the line of distinc- 

 tion between Notholena, on the one hand, and Pteris or AUosoriis, on the 

 other. Notholena is characterized by the absence of an involucre; but in 

 the young stale of many species the reflexed margin of the pinnule can 

 hardly, if at all, be distinguished from a true involucre: while, in old spe- 

 cimens of some acknowledged species of Cheilanthes, the involucre is so 

 forced back by the capsules, and concealed by them, that its presence is 

 not easy to be recognized at all, especially in those species where the invo- 

 lucre is of the same texture as the frond. Then with regard to Pteris and 

 Allosorus, it is quite certain that where the involucres of Cheilanthes are 

 confluent, as is so frequently the case (not so in true Ili/polepis) and conti- 

 nuous, the fructification to all appearance is that of Pteris and Allosorus. 

 It is true that in most cases the specimen, in some of the pinnules, does 

 exhibit free and punctiform involucres, (as we have observed of some of the 

 HypoU'pis genus) : but there are numerous other cases of species, referred 



