140 FLORA OF THE UPPER SUSQUEHANNA. 



An elegant species, much less like the popular conception of a 

 fern than most of our common species. 



O. Claytoniana L. Interrupted Flowering Fern. Clwtoss's 

 Fern. Common in low grounds, especially in thickets along 

 streams. Sterile fronds once pinnate, the pinnae pinnatifid. 

 Fruit borne on two or more pairs of much contracted pinnae in 

 the middle of an otherwise unchanged frond. This species 

 fruits as the fronds unroll. 



O. cinnamomea L. Cinnamon Fern. Very common in all low 

 grounds. Fronds in a circular clump, the sterile pinnate with 

 the pinnse pinnatifid, the fertile fronds much contracted, covered 

 with cinnamon- colored sporangia, appearing earlier than the 

 sterile ones. 



OPHIOQLOSSACE/C. 



BOTRYCHIUM Sw. 



B. simplex E. Hitchcock. Mugnwort. Swamp at the head of 

 Bennett's Lane, Oxford, i8S6, Cavil le. Unadilla Forks; rare, 

 Brown. The only stations 



B. lanceolatum (S. G. Gmel.) Angs. Lanceolate Moonwort. 

 Woods at base of Mt. Markham, Brown. In same situations as 

 the following and almost invariably accompanying it, Coville. 



B. matricarisefolium A. Br Rare. Woods at base of Mt. Mark- 

 ham, BroTun. Beech and maple woods at various points in 

 Oxford and Preston, C67'ille. 



B. ternatum (Thunb.) Su'. Ternate Moonwort. Grape Fern. 

 Plentiful on dryish knolls. Sterile portion of the plant broadly 

 triangular, ternate and variously divided. Fertile portion erect, 

 often four times pinnate Our common form of the plant may 

 be referred to the variety obliquuin. A form with the seg- 

 ments cut into narrow lobes or teeth is occasionally found and 

 IS the variety ({isscctmi}. 



B. Virginianum (L. ) Sw. Raitli.snake Fkrn. Grape Fekn. 

 \'iR<;iNiAN Moonwort. Common in rich, moist woods through- 

 out our range. In appearance like the preceding, except that 

 the plant is taller with thinner fronds. It is found much earlier 

 in the season than B. ternatiini. 



