26 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



2. Botrychium lanceolatum (S. G. Gmel.) Angs., Bot. Notiser 1854: 



68. 1854. 



Osmunda lanceolata S. G. Gmel., Nov. Comment. Acad. Petrop. 

 12: 516. 1768. 



San Francisco Peaks, 11,000 feet, subalpine meadows (Little 4679, 

 4740). Newfoundland and Quebec to northern Maine; Alaska, 

 southward in the mountains to Colorado and Arizona; Greenland; 

 Eurasia. The var. angustisegmentum Pease and Moore is found from 

 Newfoundland to West Virginia, westward to Wisconsin. 



3. Botrychium lunaria (L.) Swartz, Jour. Bot. Schrad. 1800 2 : 110. 



1801. 



Osmunda lunaria L., Sp. PL 1064. 1753. 



San Francisco Peaks, 11,000 feet, open spruce-fir forests (Kearney 

 and Peebles 12123, Little 4741, Collom 890). Labrador and Newfound- 

 land to Alaska, southward in two or more varietal forms to Maine, 

 New York, Michigan, Colorado, Arizona, and southern California; 

 Argentina; Greenland; Eurasia; Australia; New Zealand. 



2. POLYPODIACEAE. Fern family 



Leafy vascular plants of varied habit, the rhizomes paleaceous or 

 hairy, creeping to erect; fronds usually stalked; blades simple to 

 several times pinnatifid or pinnate, coiled in vernation; sporangia (in 

 our species) borne in clusters or lines (sori) upon the back of the 

 blades, mostly long-stalked, provided with an incomplete vertical ring 

 of thickened hygroscopic cells (the annulus), splitting transversely; 

 sori with or without a membranous protective organ (indusium); 

 prothallia green, epigean. 



Key to the genera 



1. Sori dorsal upon the veins, separate, not marginal (2). 



2. Indusium attached to receptacle beneath the sporangia, its divisions spread- 

 ing on all sides 1. Woodsia. 



2. Indusium, if present, centrally peltate or attached at the sinus (3). 

 3. Sori round to oval (4). 



4. Stipes jointed to the rhizome; blades deeply pinnatifid; indusia wanting. 



2. POLYPODIUM. 



4. Stipes not jointed; blades 1- to 3-pinnate; indusia present (5). 

 5. Indusium orbicular, centrally peltate (6). 



6. Sori in a single row at either side of the midrib. 3. Polystichum. 



6. Sori in 2 or more rows 4. Phanerophlebia. 



5. Indusium not as above (7). 



7. Indusium firm, roundish-reniform, attached at its sinus. 



5. Dryopteris. 

 7. Indusium membranous, hood-shaped, attached by its base at one 



side, early thrust back 6. C ystopteris. 



3. Sori oblong or linear to lunate or hippocrepiform (8). 



8. Venation partially areolate, the large tumid sori borne in a chainlike 



row close to the midribs 7. Woodwardia. 



8. Venation free; sori oblique (9) 

 -9. Rhizome scales with thin-walled cells; blades large, delicate; sori 



mostly lunate or hippocrepiform 10. Athyrium. 



9. Rhizome scales with dark-walled cells; blades small; sori oblong to 

 linear, straight or nearly so (10). 



10. Blades sinuate-pinnatifid 8. Ceterach. 



10. Blades pinnate 9. Asplenium. 



