Puate 48. 
WOODSIA (§ Prrriyia) optusa, Hook. 
Obtuse Woodsia. 
Woopsta (§ Perrinia) obtusa; frond broad-lanceolate, glabrous, or minutely 
glanduloso-pilose, bipinnate ; pinne remote, subopposite, slightly petiolate, 
deltoideo-ovate, obtusely attenuated, deeply pinnatifid, the lower ones again 
pinnate; segments or pinnules oval-oblong, dentate or inciso-lobate ; sori 
solitary on each tooth or lobule near the sinus; involucres glabrous, very 
thin and fragile, soon breaking down into spreading laciniated lobes ; stipes 
and base of rachis partially chaffy. 
Woopsta obtusa. Hook. Gen. et Sp. Fil. v. 1. p. 63. Asa Gray, Man. of Bot. 
Illustr. p. 595. 6.12, 4, and 5. 
PuysEMatium obtusum. Hook. Fl. Bor. Am. v. 2. p. 259. 
AsPipium obtusum. Willd. Sp. Pl. v. 6. p. 254. Schk. Fil. t. 43 (figure bad). 
Pursh, Fl, Am. v. 2. p. 262. : 
Potypoprum obtusum. Sw. Syn. Fil. pp. 39 and 420. Schk. Fil. p. 18. ¢. 21. 
Woopsia Perriniana. Hook. and Grev. Ic. Fil. v. 1. é. 68. 
PHYSEMATIUM Perrinianum. Kze. Anal. Plerid. p. 43. 
AusopHita Perrinina. Spreng. 
Has. United States of America ; Pennsylvania to Virginia, rocky banks and cliffs, 
Pursh, Torrey, Asa Gray, etc.; and south as far as New Mexico, gathered 
by Mr. C. Wright, im 1851-2, n. 2119 and 2120. We have splendid 
specimens from Kentucky, Dr. Short (18 inches high, including the stipes). 
West side of the Rocky Mountains, Douglas, Drummond, near the sources 
of the Columbia. We have recently received fine specimens, gathered by 
Dr. Lyall, of the Oregon Boundary Commission, in British North-west 
America, north lat. 49°, 2. 140. California, Dowglas—This has been for 
many years in cultivation in the temperate fern-house at Kew. 
Our herbarium contains copious specimens of Woodsia, from 
the Andes of South America, some of which seem nearly allied to 
the North American WV. obtusa : but they require careful study 
and comparison before the specific distinctions can be identified. 
The genus itself, as we have considered it, has three forms of in- 
volucre, of which we have ventured to constitute so many groups 
or subgenera :—1l. Physemativm, with the involucre at first glo- 
bose, and probably entire, afterwards bursting at the top, with an 
irregular contracted opening, and persistent (this is the genus 
Physematium, K\fs., and Hymenocystis, C. A. Meyer). 2. Per- 
rinia, involucre subhemispherical, from an early stage opening 
at the top, and soon breaking down into spreading, irregular, 
NOVEMBER lst, 1861. 
