ORDER CXLII. FILICES FERN-FAMILY. 



221 



7. CTSTOPTERIS. Sori roundish. Indnslum oblong-reniform, cuculkte, In- 

 flated at base, attached by the inner side, and opening on the other. 



8. Wo6osiA. Sori alobular. Indusium attached by the base all the way 

 round, opening above at the centre. 



9. DRYOPT KRIS. Sori round. Indusium round-reniform, flattened, opening 

 all round. 



10. PoLYSTiniuM. Sori round. Indusium orbicular, depressed and attached 

 at the centre, opening aU round. 



11. ONOCLEA. Sori on separate, smaller fronds, inclosed in a sort of berry- 

 like involucre, at first separate, at length confluent 



SUBOEDEK II. OsmnndinesB. 



Sporangia naked, destitute of a ring, opening by a longitudinal slit. Frond 

 circinate in the bud. 



12. OSMCNDA, Sori large, subglobose, pedicellate. 



SUBORDER III. Ophioglosseae. 



Sporangia 1-celled, opening by a transverse slit, destitute of a ring. Frond 

 not circinate in the bud. 



13. BOTRYCHIUJI. Sporangia in a racemose panicle, distinct. 



1. POLYP6DITJM. 



Sori roundish, irregularly scattered ou the under surface of 

 the frond. Indusium none. 



1. P. vulgare. 



Polypod. 



Frond oblong in outline, deeply pinnatifld ; segments oblong, obtuse, obscurely 

 crenate, green on both sides ; stipe smooth, naked ; sori large, roundish. A 

 common evergreen fern in woods, where its creeping, scaly rhizomas form large 

 patches, distinguished by the oblong, simply pinnatiBd fronds and nearly entire, 

 oblong segments. Frond 6' 18' high. July. 



2. P. Phegopteris. Triangular Polypod. 



Frond annual, twice pinnatifld, triangular in outline, longer than broad, 

 iiairy on the veins ; pinnae lanceolate ; 2 lower ones deflexed ; the ultimate seg- 

 ments oblong-linear, entire, sori minute. An elegant fern, distinguished by 

 its triangular outline, and the deflexed lower pair of pinnae, which' make it ap- 

 pear somewhat hastate. Khizoma blackish. Frond 6' 12' high. Bather com- 

 mon in rich, rocky woods, especially towards the North. July. 



3. P. Dryopteris. 



Ternate Polypod. 



Stipe very slender, smooth, brittle; frond ternate, divisions twice pinnate, 

 spreading, deflexed, light green, very thin and delicate in texture ; ultimate 

 segments oblong, obtuse, somewhat crenate ; sori on the margin ; rhizoma fili- 

 form, creeping. An exceedingly delicate and beautiful fern, growing in the 

 shade of rocky, and especially mountainous woods. Frond 4' 8' high. July. 



2. STKUTHI6PTEKIS. 



Sori on separate, smaller fronds, at length covering the entire 

 lower surface, arranged on the pinnate, unconnected veins, desti- 

 tute of an indusium. 



I. S. Grermanica. Ostrich Fern. 



Sterile fronds tall, with stout, smooth, channelled stipes, pinnate ; pinnoe 

 sessile, pinnatifld ; ultimate segments entire ; fertile fronds much smaller, with 

 numerous, contracted, brownish segments covered with sori. A very large 

 and showy fern, not uncommon in low, rich woods, growing in clumps. The 

 fertile fronds are about afoot high, the sterile frondi 8 4 ft., and even higher. 

 Aug. 



8. PTfeKIS. 



Sori linear, very narrow, confluent in a continuous, marginal 

 line. Indusium continuous, attached by the margin. 



1. P. aquilina. Brake. 



Stipe erect, stout, bearing the ternate frond at summit ; divisions bipinnate, 

 very spreading; ultimate segments oblong-lanceolate; upper segments entire ; 

 lower somewhat pinnatifld, with obtuse, oblong lobes. A tall stout fern, trian- 

 gular in outline, with a dull green frond, and usually purple stipe. Very com- 

 mon in pastures, fields and thickets. The continuous indusinm forms a margin 

 to all the segments of the frond, which, together with the stipe, is 2 ft high. 

 Aug. 



4. ADIANTTTM. 



Sori roundish, marginal on the lobes of the frond. Indusium 

 reniform, appearing like a reflexed margin of the frond, and bear- 

 ing the sporangia on its under surface. 



1. A. pedatum. 



Maiden-hair. 



Stipe erect, slender, black, bearing a 2-parted frond at top, each division con- 

 sisting of several slender segments branching from ono side, and bearing nu- 

 merous, oblong-rhomboid segments, which are oblique, potiolate, entire on the 

 margin next the racbis, inciscly out at the other margin, appearing as if valved, 

 and of a glaucous green. A very elegant and graceful fern, distinguished by 

 the black, polished stipe and branches, and delicate foliage, 8' 15' high. July. 



5. ASPLENIUM. 



Sori linear or oblong, oblique, scattered, attached lengthwise. 

 Indusium opening lengthwise in the direction of the mid-vein. 



1. A. ebeneum. 



Ebony Spleenwort. 



Frond on a short, smooth stipe, erect, linear-lanceolate in outline, pinnate; 

 pinnae lanceolate-oblong, somewhat falcate, serrate, sessile, auriculate at base 

 on the upper side ; sort numerous, in short lines on both sides of the mid-rib. 

 A slender, elegant fern, with a smooth purple stalk, growing 6' 15' high. 

 Common in rocky woods. Aug. 



2. A. Trichomanes. Dwarf Spleenwort. 



Fronds tufted, linear in outline, pinnate; pinnae small, roundish-elliptical, 

 nearly sessile, oblique and entire at base, crenate above. A delicate little fern, 

 common in tufts on shaded rocks, 8' 7' high, with very slender, purple stalks. 

 July. 



3. A. thelipteroides. Silvery Spleenwort. 



Frond with a chaffy stipe, pinnate ; pinnae deeply pinnatifld, linear-lanceo- 

 late ; ultimate segments oblong, obtuse, with 2 rows of shining, silvery sori, 

 which, when young, are covered with shining, silvery indusia. A handsome 

 fern of a pale green color, not uncommon in low, shaded grounds. It is dis- 

 tinguished before maturity by the shining silvery hue of the indusia. Frond 

 13 ft high. July. 



4. A. Filix-foemina. Common Spleenwort. 



Frond oblong, or oblong-lanceolate in outline, bipinnate, entirely smooth ; 

 pinnae lanceolate, acuminate; segments oblong-lanceolate, pinnatifldly cut and 

 toothed ; sori large, oblong, numerous, finally confluent over the whole under 

 surface of the frond, and giving it a dark-brown color. Very common in moist 

 fields and woods. Frond 23 ft high. July. 



6. DICKS6NIA. 



Sori roundish, marginal, distinct. Indusium double ; one con- 

 sisting of a recurved, 2 lipped, little sac, that opens outward, 

 and is attached by its edges to the proper indusium, which is 

 marginal and opening inward. 



1 . D. punctilobula. 



Gossamer Fern. 



Frond slightly hairy, ovate-lanceolate in outline, pinnate ; pinnae deeply 

 twice pinnatifld ; ultimate segments cut and toothed ; sori minute. A very 

 delicate and beautiful fern, remarkable for the numerous and very fine divisions 

 of its pale-green frond, 23 ft high. July. 



7. CYST6PTERIS. 



Sori roundish. Indusium oblong-reniform, cucullate, inflated 

 at base, attached by the inner side, and opening on the other* 



1. C. fragilis. Bladder Fern. 



Frond oblong-lanceolate in outline, bi- or tri-pinnate ; ultimate segments ob- 

 long or oblong-ovate, more or less pinnatifld and toothed ; rachis winged by the 

 decurrent segments. A slender and variable species, common on moist, shaded 

 rocks. July. 



8. WOtfDSIA 



Sori globular. Indusium thin, attached by the base all tho 

 way round, open above, at the centre, with a variously cut and 

 fringed margin. 



1. W. obtusa. 



Hairy Wood Fern. 



Frond ovate-lanceolate in outline, very slightly hairy ; pinnae ovate or oblong, 

 very broad at base so as to be somewhat triangular, almost pinnate again ; ulti- 

 mate segments oblong, rounded at apex, pinnatifldly divided into lobes, each of 

 which bears a single fruit-dot A little fern 6' 8' high, growing in tufts on 

 rocks. The stipe is slightly chaffy. 



