318 BOTANY. 
of the pinnules; involucres continuous, formed of the membranaceous and 
somewhat altered margin of the pinnule, at first reflexed along the two 
sides and meeting at the midrib, at length opening out flat ; rootstock short; 
stalks stramineous, tufted; fronds smooth, herbaceous, dimorphous ; sterile 
ones on shorter stalks, trimquadri-pinnatifid, with toothed or incised ovate or 
obovate segments; fertile ones long-stalked, less compound, with narrowly 
elliptical or oblong-linear pod-like segments.—Allosorus, Bernhardi, in part. 
The generic name was proposed in 1823 by Robert Brown, in Dr. Rich- 
ardson’s Appendix to Franklin’s first journey, for our species, and with it he 
associated the European Pteris crispa, Linn. Allosorus of Bernhardi is a 
much older name, but the character assigned to it was exceedingly vague, 
and the species referred to it, if by Bernhardi’s expression “alle Adianta 
spuria Sw.” we are to understand the species of Pteris which Swartz placed 
in his section Adiantoidee, are now scattered among half a dozen diverse 
genera. Presl’s Allosorus is likewise worthless, being a most heterogeneous 
assemblage of unlike species. Since the true object of scientific nomen- 
-clature in botany is to clearly set forth natural affinities and distinctions, 
and not, as some would have it, to perpetuate antiquated obscurities, | am 
quite content to follow the great masters Robert Brown and Sir W. J. 
Hooker in using the name Cryptogramme, though the name Allosorus may 
perhaps be kept, as by Mr. Baker, for a section of Pellea. 
Cryptogramme acrostichoides, R. Brown.—Cr. crispa, forma Ameri- 
cana, Hook. Sp. Fil. ii, p. 130. Allosorus acrostichoides, Sprengel, Gray’s Manual. 
Usually in dense tufts among rocks, often at high elevations. Isle Royale, Lake Superior, and 
generally in the Rocky Mountains and the Sierra from Colorado and California northward to 56° or 60° 
north latitude (Dr. Richardson), and in the Aleutian Islands, where it has a more condensed habit 
(Allosorus foveolatus, Ruprecht). The American plant is considered a form of the European C., crispa by 
Sir W.J. Hooker and by Dr. Milde, and one occasionally sees specimens which would seem so inter- 
mediate in charater as to justify this disposition, but the American plart is decidedly more rigid and 
subcoriaceous than the other, has less compound fronds, less incised sterile segments, and longer and 
more linear fertile ones. In C. crispa, the sporangia occupy only the upper portion of the fertile veins, 
and in C. acrostichoides they descend nearly or quite to the midrib. Curiously enough, Dr. Milde makes 
Pellea gracilis also a form of his Allosorus crispus. 
VI. PELLZA. Link. 
§ 1. CHEILOPLECTON. Fée, Baker. 
“* Texture herbaceous or subcoriaceous, and veins clearly visible, the imvo- 
lucre broad, and in most of the species rolled over the sorus till full maturity.” 
