84 Our Native Ferns. 



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 pinnae longest, 

 the lower gradually shorter and deflexed ; sori short, abundant. 

 (A. ebeneum, var. minus, Hook.) Va., S. C. and Fla. to Ark. and 

 N. .\Iex. VI. 



6. A. Trichomanes, L. Stipes densely tufted, purple-brown, 

 shining; fronds 3'— 8' long, y^' or more broad, linear; pinnae 15 — 

 30 pairs, nearly opposite, roundish-oblong or oval, the two sides 

 unequal, obliquely wedge-truncate at the base, attached by a nar- 

 row point, the edge slightly crenate, the midvein forking and 

 evanescent; sori 3 — 5 on each side of the midrib. Eastern U. S. 

 to the Pacific coast. I. 



Var. incisum, Moore. Fronds larger, often }i' or more broad, 

 pinnae more or less deeply incised. Cal., Vt. 

 XRachis green. 



7. A. viride, Huds. Stipes densely tufted, 2' — 4' long, naked, 

 the lower part chestnut-brown ; fronds 2' — 6' long, %' broad, with 

 12 — 20 pinnae on each side, which are ovate or rhomboidal in out- 

 line, the upper edge narrowed suddenly at the base, the lower 

 obliquely truncate, the outer part deeply crenated ; rachis naked ; 

 sori copious. Vt., Canada, and N. B. II. 



8. A. dentatum, L. Stipes tufted, 1' — 6' long, naked, ebene- 

 ous below ; fertile fronds 2' — 3' long, \' broad, with 6—8 pairs of 

 stalked, oblong-rhomboidal pinnae, the lower side truncate with a 

 curve, the outer edge irregularly crenate ; sterile fronds smaller 

 on shorter stipes ; rachis naked ; sori copious in parallel rows. 

 Fla., S. C. VI. 



'^PinncB only 2 — 5, linear-cuneate. 



9. A. septentrionale, Hoffm. Stipes densely tufted, 3' — 6' 

 long, slender, naked, ebeneous toward the base ; fronds irregu- 

 larly forking, consisting of two to five narrowly linear rather rigid 

 segments, which are entire or more frequently cleft at the end 

 into a few long narrow teeth ; sori much elongated, placed near 

 the margin, usually facing each othefin pairs, commonly only two 

 or three to each segment. Col., N. Mex. V. 



\\\ Pinna numerous, linear or linear-oblong, acute or acuminate. 



10. A. angustifolium,* Michx. Stipes 1° or more long, brown- 

 ish, slightly scaly below ; fronds ij" — 2° long, 4' — 6' broad, lance- 

 olate-oblong, flaccid ; pinnae 20 — 30 pairs, linear-lanceolate, acu- 

 minate, entire or crenulate, those of the fertile frond narrower ; 



