32 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



rocky canyons. Known otherwise only from Abyssinia and the 

 mountains of southern Asia. A similar instance of discontinuous 

 range is that of Asplenium exiguum Bedd. 



This species is of doubtful systematic position. In habit it closely 

 resembles the Old World type species of Ceterach (C. officinarum DC), 

 but differs in its free veins and well-developed indusia and thus might 

 almost equally well be referred to Asplenium, as was long done. 



9. ASPLENIUM. Spleenwort 



Ferns of moist cliffs and rocky woods, of various habit, the rhizome 

 scales with dark partition cell walls; fronds uniform, the blades once 

 to several times pinnate or pinnatifid, the rachises often dark and 

 shining; veins free; sori oblong to linear; indusia always present, 

 attached laterally. 



Key to the species 



1. Plants grasslike, densely tufted; blades short, alternately divided into a f ew» 



very oblique, narrowly cuneate segments 1. A. septentrionale. 



1. Plants not grasslike; blades with simple or pinnately cleft or parted, spreading 

 pinnae (2). 

 2. Blades narrowly lanceolate or triangular (3). 



3. Leaf tissue herbaceous; blades narrowly lanceolate; pinnae subequal, 

 narrowly oblong, sharply incised 6. A. exiguum. 



3. Leaf tissue coriaceous; blades triangular; pinnae much larger, unequal 



the large basal ones deltoid, once or twice pinnately parted. 



7. A. ADIANTUM-NIGRUM. 



2. Blades linear; pinnae subentire to crenate or dentate (4). 



4. Sori few (1 to 3), confined to the proximal side of the pinnae. 



2. A. MONANTHES. 



4. Sori numerous, in pairs, i. e. those of the distal and proximal sides about 

 equal in number (5). 

 5. Pinnae distinctly toothed; fronds mostly recurved and rooting at tip. 



3. A. PALMERI. 

 5. Pinnae subentire or crenulate; fronds not radicant (6). 



6. Stipes blackish; pinnae oblong, coriaceous, auriculate; sori short, 



nearer the margin than the mid vein 4. A. resiliens. 



6. Stipes dark castaneous or purplish brown; pinnae oval to broadly 

 oblong, herbaceous, not auriculate; sori narrowly oblong, medial. 



5. A. TRICHOMANES. 



1. Asplenium septentrionale (L.) Hoffm., Deut. Fl. 2: 12. 1795. 



Acrostichum septentrionale L., Sp. PI. 1068. 1753. 



White Canyon, San Francisco Peaks, 8,000 feet, in crevices of 

 rocks (MacDougal 68), Elden Mountain near Flagstaff (Wherry in 

 1940). Black Hills of South Dakota to western Oklahoma, New 

 Mexico, Arizona, and Baja California; Eurasia. 



2. Asplenium monanthes L., Mant. 1: 130. 1767. 



Asplenium monanthemum Murray, Syst. Veg. 933. 1784. 



Huachuca Mountains, Cochise County (Lemmon in 1882, Pringle 

 in 1884, and others), about 8,000 feet, on shaded cliffs. Known in 

 the United States only from southern Arizona ; Mexico to Chile; West 

 Indies; Africa; Hawaiian Islands. 



3. Asplenium palmeri Maxon, Contrib. U. S. Natl. Herbarium 13: 39. 



1909. 

 Asplenium parvulum var. grandidentatum Goodding, Muhlen- 

 bergia 8: 92. 1912. 

 Mule Mountains, Cochise County (Goodding 976), Sycamore Can- 

 yon near Ruby, Santa Cruz County (Goodding 6148), Baboquivari 



