142 Proceedings of the Biological Society of Washington. 



Fronds few, larger, with stouter, lighter-colored stipes, 

 spaced (5-10 mm. apart), the rhizome relatively 

 more slender, with a few short, slender branches; 

 segments of the lamina prevailingly subcordate- 

 orbicular 6. C. Clevelandii. 



1. Cheilanthes myriophylla Desv. Ges. Naturf. Freund. Berlin Mag. 

 5: 328. 1811. 



Cheilanthes elegans Desv. Ges. Naturf. Freund. Berlin Mag. 5 : 328. 1811. 



Cheilanthes paleacea Mart. & Gal. Nouv. Mem. Acad. Sci. Brux. 15: 

 76. pi. 21, /. g. 1842. 



Viewed in the sense above mentioned, Cheilanthes myriophylla is a 

 variable species occurring rather commonly in mountain regions from 

 Argentina and Bolivia to northern Mexico. The numerous specimens 

 from these regions show general agreement in the following characters: 



Rhizome massive, decumbent or suberect, usually multicipital, the 

 divisions short, nodose; fronds closely fasciculate, tall, stiffly erect ; stipes 

 very densely appressed-paleaceous, the scales exceedingly numerous, 

 very narrow, conform, persistent, closely investing the stipe; lamina 

 3-4-pinnate, densely paleaceous beneath, the scales variable, the larger 

 ones of an ovate type, very firmly attached at the elevated, deeply 

 cordate base, acuminate to attenuate at the apex, nonciliate, subentire 

 to strongly erose-dentate ; numerous reduced scales of the under surface 

 and rachises tortuous, filiform, recurved among the segments and par- 

 tially overlying their upper surface; segments minute, beadlike, sessile 

 or short-stalked, bearing a few tortuous, weak, moniliform hairs above, 

 these lightly attached, readily abraded; sporangia borne well within the 

 deeply concave or cucullate rounded outer border of the segment, the 

 broad margin commonly bilobed and crenate, with paler and thinner 

 edges. Leaf tissue dull green, herbaceous. 



These characters denote a close relationship with C. villosa only, with 

 which species it is contrasted in the key. The original specimens of C. 

 myriophylla are said by Desvaux to have come from South America, the 

 particular region not being indicated. 



2. Cheilanthes villosa Davenp. Cat. Davenp. Herb. Suppl. 45. 1883. 

 Rhizome ascending or decumbent, massive (1-3 cm. in diameter), 



nodose or multicipital, the few branches close, short, and thick (5-10 

 mm. in diameter), coarsely radicose, densely paleaceous, the scales 

 tufted (especially at the apices), narrowly subulate-attenuate, 5-9 mm. 

 long, 0.5 mm. broad or less at the base, strongly falcate, flexuous in the 

 apical half, with a narrow, opaque, strongly sclerotic, dark brown median 

 band nearly throughout, the delicate translucent whitish borders with a 

 few distant, low, minute, rounded teeth. Fronds numerous, erect, dor- 

 sal, fasicculate (often appearing subcespitose ) , 10-33 cm. long; stipe 

 4-14 cm. long, 0.7-1.5 mm. in diameter, subflexuous, purplish brown, 

 with a nearly persistent covering of minute, appressed, linear scales and 

 numerous large, oblong, white or pale tawny, spreading scales ; lamina 



