594 FiLicES. (ferns.) 



10. ASPliEHriUM, L. Spleenwokt. (Tab. U.) 



JFrait-dots linear or oblong, oblique, separate ; tbe indnsium attached length ■ 

 wise by one edge to the upper (inner) side of the simple, forked or pinnate, free 

 veins, and opening along the other: — rarely some of the fruit-dots are double 

 (Diplazium), two indnsia being then borne on the same vein, back to back. 

 (Named, from a privative and (tttXiiv, the spleen, for supposed remedial prop- 

 erties.) 



^ 1. ASPLENIUM Peopek. — Indusiumnairow, fixed by its whole length. 



# Indnsium flat or flattish, thin, {Fronds evergreen.) 



1. A. pinnatifiduili, Nutt. Fronds (3' -6' long) diffusely spreading, 



lanceolate, pinnatifld, sometimes pinnately parted near the base, tapering above into 

 a slender prolongation, the apex sometimes rooting ; lobes roundish-acate, obtuse, cut- 

 toothed or nearly entire; the midrib evanescent by forking below the apex. — 

 Cliffs on the Schuylkill and Wissahickon, near Philadelphia, and southward 

 along the AUeghanies ; also sparingly westward : rai'e. July. — Resembling 

 the Walking-Leaf (Camptosorus), but the venation is that of Asplenium : fmit- 

 dots irregular, numerous, even the slender prolongation fertile. 



2. A. montanum, Willd. i^ronds (3'- 5' high, bright green) /anceo/ate 

 or triangular-oblong in outline, pinnate ; the ovate pinnce 3 - 1 -parted (or the upper 

 barely cleft) and cut-toothed ; the veins forking from a, midrib. — Cliffs, in the 

 Alleghany Mountains, from Pennsylvania (Mr. Lea) to Virginia, and southward. 

 July. — Rhachis green : stalk brownish. — Much smaller than the European A. 

 Adiantum-nigrum. 



3. A, Kuta-inuraria, L. Fronds (2' -4' long) 2-pinnate belom, simply 

 p.nnate above, ovate in outline, the few divisions narrowly rhombic-wedge-shaped, 

 toothed at the apex, without a midrib, the veins all rising from the base. — Lime- 

 stone cliffs, Vermont to Michigan, Virginia, and southward along the moun- 

 tains; scarce. July. (Eu.) 



4. A. Trlchdmaiies, L. Fi-onds (3'- 8' long) in dense spreading tufts, 

 linear in outline, pinnate: pinnce numerous, roundish-oblong or oval (3" -4" long), 

 unequal-sided, obliguely wedge-truncate at the base, attached by a narrow point, the 

 midrib evanescent ; the thread-like stalk and rhachis purple-brown and shining. 

 (A. melanocaulon, pfisVH.) — Shaded cliffs ; common. July. (Eu.) 



5. A< ebeneum, Ait. Fronds w^right (S'~ 16' high), pinnate, lance-linear 

 in outline ; pinna: (^'-I'long) many, lanceolate, or the lower oblong, slightly 

 scythe-shaped, finely serrate, sessile, the dilated base auricled on the upper or 

 both sides ; fruit-dots numerous on both sides of the elongated midrib ; stalk 

 and rhachis blackish-purple and shining. — Rocky, open woods ; rather common. 



* # Indnsium strongly convex or vaulted, thickish : fruit-dots numerous and crowded 

 on both sides of the midrib, parallel, some of them occasionally double, especially in 

 No. 7. {Fronds thin, smooth, decaying in autumn, lJ°-3° high.) 



6. A. angfUStifdlium, Michx. Fronds simply pinnate; pinnse linear- 

 lanceolate, acute, minitely wavy-toothed (S' - i' long,) ; fertile fromis more con- 



