I04 OUR NATIVE FERNS AND THEIR ALLIES. 



shorter; stipes black and polished, as is the lower part of the 

 midrib, especially beneath. Schuylkill River, above Manayunk, 

 Pennsylvania {Scott) ; Havana, Alabama {Miss Tiitwiler) ; 

 Canaan, Connecticut {Adam) ; near Poughkeepsie, New York 

 {Lown), Jackson County, Illinois {Patterson). 



*** Fronds once pinnate. 

 t Pinna; \' — f ' loni^, mostly blunt. 

 X Rack is chest nut-brown or blackish. 



4. A. platyneuron (L.) Oakes. Stipes 3' — 6' long, chest- 

 nut brown, nearly naked ; fronds 8' — 16' long, linear-lanceolate; 

 pinnae 20—40, lanceolate, subfalcate, or the lower oblong, \' — i 

 long, the dilated base auricled on the upper or both sides; 

 sori often 10 — 12 on each side. {A. eboieum Ait., Polypodium 

 platyneuron L.) Florida and Kentucky northward to Canada. 



5. A. parvulum Mart. & Gale. Fronds tufted, erect, 

 rigid, 4' — 10' long, narrowly linear-lanceolate; stipe and rachis 

 black and shining; pinnae numerous, oblong, obtuse, entire or 

 crenulate, auricled on the upper side, nearly sessile; middle 

 pinna; longest, the lower gradually shorter and deflexed ; sori 

 short, abundant. {A. ebenenni var. minus. Hook., A. resiliens 

 Kunze.) Virginia, South Carolina, and Florida to Arkansas and 

 New Mexico. 



6. A. trichomanes L. Stipes densely tufted, purple- 

 brown, shining; fronds 3' — 8' long, ^' or more broad, linear ; 

 pinnae 15 — 30 pairs, nearly opposite, roundish-oblong or oval, 

 the two sides unequal, obliquely wedge-truncate at the base, at- 

 tached by a narrow point, the edge slightly crenate, the mid- 

 vein forking and evanescent; sori 3 — 6 on each side of the mid- 

 rib. {A. melanocaulon Willd.) Eastern United States to the 

 Pacific coast. 



Var. incisum Moore. Fronds larger, often f or more 

 broad, pinnae more or less deeply incised. California, Vermont. 



7. A. monanthemum L. Stipes densely tufted, 3—6' 

 long, chestnut-brown ; fronds 6' — 12' long, narrow, with 20—40 

 pinnae on each side; pinnae crenate above, abruptly narrowed 

 at base, often auricled, the lower much reduced; texture sub- 

 goriaceous; veins flabellate ; sori i — 2, linear-oblong, parallel 



