20. WOODSIA, R. Brown, 1810. 
This genus I have named in honor of my friend 
Mr. Joseph Woods . . R. Brown, Trans. Linn. 
Soc, 11: 171, 
Rootstock short, ascending. Leaves 2-pinnatifid to 
2-pinnate. Sori situated near the end of the veinlets. 
Indusium globular, at length splitting into numerous 
lobes. 
t Leaves 2-pinnatifid, pinnae somewhat crowded. 
1. W. ilvensis (L.) R. Brown. 
Acrostichum ilvense £. Sp. Pl. 1071. 
Woodsia tlvensis R. Brown, \. c. 173. Eaton, 
Ferns 2: 111. t. 60. ff. 5-8; in Gray, Man. 6g0. 
Underw. in Ill. Fl. 1: 10; Nat. Ferns 121; in 
Britt. Man. 18. Clute, Ferns 93. Waters, Ferns 
273. 
Rusty Woopsia. 
Plants 1-2 dm. high, growing in clusters; leaves line- 
ar-lanceolate; pinnae deeply pinnatifid, ovate-oblong, 
I cm. or less in length, sessile, more or less covered with 
a brownish chaff, lobes rounded ; sori confluent, at length 
covering more or less the lower face of the leaf. 
In crevices of rocks, 
Stony Man Mt., Va., Steele, W. Palmer, King. 
tt Leaves 3-pinnatifid, pinnae rather distant, 
2. W. obtusa (Spreng.) Torr. Pld, 
Polypodium obtusum Spreng. 1804. Anl. 3:92. 
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