594 FILICTSS. (PERNS.) 



IO. ASPL.t3NIUM[, L. SPLEENWORT. (Tab. 11.) 



Fruit-dots linear or oblong, oblique, separate; the indusium 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 indusia being then borne on the same vein, back to back. 

 (Named, from a privative and <nrXqi>, the spleen, for supposed remedial prop- 

 erties.) 



1. ASPLENIUM PROPER. Indusium narrow, fixed by its whole length. 

 # Indusium fiat or fiattish, thin. (Fronds evergreen.) 



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

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

 a slender prolongation, the apex sometimes rooting; lobes roundish-ovate, 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 Alleghanies ; also sparingly westward : rare. July. Resembling 

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

 dots irregular, numerous, even the slender prolongation fertile. 



2. A. moiitfsiiiini, Willd. Fronds (3' -5' high, bright green) lanceolate 

 or triangular-oblong in outline, pinnate ; the ovate pinnae 3-7-parted (or the upper 

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

 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. Rllta-muraria, L. Fronds (2' -4' long) ^-pinnate below, simply 

 pinnate 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. Trichomanes, L. Fronds (3'- 8' long) in dense spreading tufts, 

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

 unequal-sided, obliquely 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, Wittd.) Shaded cliffs ; common. July. (Eu.) 



5. A. cl>euenm, Ait. Fronds upright (8' -16' high), pinnate, lance-linear 

 in outline ; pinnce ('-!' 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. 



# * Indusium strongly convex or vaulted, thicJdsh : fruit-dots numerous and crowded 

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

 No. 7. (Fronds thin, smooth, decaying in autumn, l-3 high.) 



6. A. angustifolium, Michx. Fronds simply pinnate,' pinnae linear- 

 lanceolate, acute, minitely wavy-toothed (3' - 4' long) ; fertile fronds more con- 



