180 Proceedings of the Biological Society of Washington. 



natus as a straight synonym of Pellaea ornithopus Hook.* 

 The latter name, though singularly appropriate, must evidently 

 give way to Pellaea mucronata, limited to the abundant Califor- 

 nia plant. 



Not much attention appears to have been given to the Pellaea 

 Wrightiana and P. longimucronata of Hooker, founded respec- 

 tively on nos. 2130 and 2131 of Charles Wright's New Mexican 

 collections of 1851-52. They have been regarded as forms of a 

 single species, P. Wrightiana. Actually they represent two 

 species, and the characters by which they may be distinguished 

 are those given originally by Hooker and restated by Davenport.f 

 the latter recognizing longimucronata only varietally, however. 

 Davenport's variety compacta appears to be a valid species, 

 allied to P. mucronata (P. ornithopus). 



The synynomy and range, and some of the distinctive char- 

 acters of the four species, are given below. The rhizome scales 

 exhibit such pronounced variation in nearly all respects as to 

 be of far less importance than is usual, and characters drawn 

 from them are purposely omitted. 



Pellaea mucronata (D. C. Eaton) D. C. Eaton in Torr. U. S. & Mex. 



Bound. Bot. 233. 1859. 

 Allosorus mucronatus D. C. Eaton, Ainer. Journ. Sci. II. 22: 138. 1856. 

 Pellaea ornithopus Hook. Sp. Fil. 2: 143. pi. 116. A. 1858. 

 Allosorus ornithopus Kuntze, Rev. Gen. PI. 2 : 806. 1891. 



Type. — Collected on "hills near the bay of San Francisco, California," 

 by Major A. B. Eaton. The label accompanying the specimen gives the 

 additional locality ''Monte Diablo." 



Distribution. — Widely distributed in California, occurring from Men- 

 docino County southward in the Coast Ranges to San Diego County and 

 Lower California, and from Shasta and Lassen Counties southward 

 through the foothills of the Sierra Nevada, ascending to 1,650 meters in 

 El Dorado County, or possibly higher, t 



An extremely variable species, showing the utmost diversity in size, 

 number, and spacing of segments, according to season, habitat, and geo- 

 graphical position. What may be regarded as the normal form is that 

 figured by D. C. Eaton in Ferns of North America, § but there are many 

 departures from this, the more noteworthy being (1) extremely luxuriant 

 specimens from Los Angeles County, with pinnae alternate, many of 



• Op. cit, 2 : 12. 



+ Cat. Davenp. Herb. Suppl. 45, 46. 1883. 



t Reported by Watkins (Fern Bull. 10: 70. 1902) to ascend to 9.000 feet in the Sierra 

 Nevada. 



§2: pi. i7, Jigs. 7-10. 



