10 



POLYPODIACEAE. 



x. Woodsia Ilvensis (L.-i R. Br. Rusty \Voodsia. (Fig. 16.) 



Acrosticlntm Ilrense L. Sp. PI. 1071. 1753. 



sia Ilrcnsis R. Br. Trans. Linn. Soc. n : 173. 

 1812. 



Rootstock short, caespitose. Leaves lanceolate, 4'- 

 ic/ long, pinnate, glabrous above, more or less covered 

 with rusty chaff beneath, as are also the slender stipes ; 

 pinnae crowded, sessile, pinnately parted, the crowded 

 segments oblong, obscurely crenate ; stipes jointed 

 near the base ; son borne near the margins of the 

 segments, somewhat confluent when old ; indusium 

 minute, concealed beneath the sorus, its margin cleft 

 into filiform segments which are inflexed over the 

 sporanges and inconspicuous, especially when the 

 latter have scattered their spores. 



On exposed rocks, Labrador and Greenland to the 

 Northwest Territory, south to North Carolina and Ken- 

 tucky. Ascends to 5000 ft. in New Hampshire. Also in 

 Europe and Asia. June-Aug. 



2. Woodsia alpina ( Bolton) S. F. Gray. 

 Alpine Woodsia. (Fig. 17.) 



>//<//;// alpinum Bolton. Fil. Brit. 76. 1790. 

 'iihtim hvperborettin Liljeb. Act. Stockh. 201. 

 '793 



Woodsia hyperborea R. Br. Trans. Linn. Soc. n: 173. 

 1812. 



~ia alpina S. F. Gray. Nat. Arr. Brit. PI. 2: 17. 

 1821. 



Rootstock short, caespitose. Leaves narrowly ob- 

 long-lanceolate, 2 r -6' long, $"-12" wide, scarcely 

 narrower below the middle ; pinnae cordate-ovate 

 or triangular-ovate,, pinnately 5~7-lobed, glabrous 

 or very nearly soon both surfaces; stipes jointed 

 near the base ; sori somewhat scattered on the seg- 

 ments ; indusium as in the preceding species. 



( ti m.i-.t rocks. Labrador to Alaska, south to Maine, 

 northt-ni New York and western Ontario. Ascends to 

 4200 ft. in Vermont. July-Aug. 



3. Woodsia glabella R. Br. Smooth 

 Woodsia. (Fig. 18). 



U'mxfsfa glabella R. Br. App. Franklin's Jouni. 7S4. 

 1823. 



Rootstock small, caespitose. Stipes obscurely 

 jointed .at the base ; leaves linear or narrowly lan- 

 ceolate, 2 / -5 / long, 4" 8" wide ; pinnae deltoid to 

 ovate, the lower remote, obtuse, crenately lobed, 

 often somewhat smaller than the middle ones, 

 glabrous or nearly so ; sori scattered on the seg- 

 ments ; indusium minute, membranous, with 6-10 

 radiating segments, covered by the sporanges, its 

 filamentous segments only inflexed over them 

 \vheu young as in the two preceding species. 



on moist rocks, Labrador to Alaska, south to" New 

 H impshire, Vermont, northern New York and the 

 north shore of Lake Superior. Also in arctic and 

 alpine Europe and Asia. Summer. 



