Vol. 32, pp. 111-112 May 20, 1919 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



A NEW CHEILANTHES FROM MEXICO. 

 BY WILLIAM R. MAXON. 



In distinguishing recently 2 the characters separating Cheilan- 

 thes tomentosa Link and C. Eatoni Baker, whose ranges overlap 

 in the territory from Oklahoma to the Mexican border region 

 of New Mexico and Arizona, the following apparently unde- 

 scribed Mexican species was detected: 



Cheilanthes castanea Maxon, sp. nov. 

 Rhizome short-creeping, nodose or short-branching, the divisions 1 to 

 3 cm. long, less than 1 cm. thick, densely paleaceous, the scales oblique, 

 imbricate, falcate, 3 to 3.5 mm. long, about 0.6 mm. broad at the base, 

 subulate-attenuate, rather lax, tawny, with a distinct glossy, dark brown, 

 sclerotic, median stripe extending nearly to the filiform, flexuous tip. Fronds 

 few, very closely distichous, erect, 16 to 30 cm. long; stipe 9 to 18 cm. long, 

 castaneous, sublustrous beneath a thin covering of appressed to rigidly 

 ascending, pale tawny scales, the larger of these linear-attenuate, underlaid 

 by minute acicular ones; lamina linear to linear-oblong, long-acuminate, 

 7 to 17 cm. long, 2 to 4 cm. broad, tripinnate, the rachis similar to the stipe 

 but with larger and more numerous scales; larger pinnae 8 to 12 pairs, 

 spreading (or with age oblique and involute), distant, sessile, deltoid- 

 oblong, acutish, slightly inequilateral; secondary rachises persistently 

 paleaceous, the scales rather large, flaccid, imbricate, linear-deltoid to 

 ovate, long-acuminate, firmly attached at the cordate base, erose-denticu- 

 late, tawny; segments of the larger pinnules mostly 3 or 5, oblong, entire, 

 unequal, the terminal ones the longest (up to 4 mm. long), with a cuneate 

 base; segments loosely but copiously tomentose beneath with spirally 

 crispate, light castaneous hairs, glabrate above, the few similar but griseous 

 hairs easily deciduous; segments mostly fertile, the recurved margin gradu- 

 ally thinner, slightly repand, minutely sinuate, pale, hardly forming a 

 proper indusium; sporangia not concealed at maturity, the tomentum 

 separating evenly from the indusiiform margin. Leaf tissue rather rigidly 

 herbaceous, dull grayish green. 



i Published with the permission of the Secretary of the Smithsonian Institution. 

 SAmer. Fern Journ. 9: 3, 4. 1919. 



19— Proc. Biol. Soc. Wash., Vol. 32, 1919. (Ill) 



