FILICES. (FERNS.) 685 



stalked (2 - 5" long), from narrowly cuneate to roundish-obovate, toothed or in- 

 cised at the apex ; veins forking ; sori 2-4 on a segment. Limestone cliffs, 

 Vt. to Mich., and southward ; scarce. July. (Eu.) 



* * * * Tall ferns (2-4 high), not evergreen ; fronds pinnate or sub-bipinnate. 



10. A. angustifblmm, Michx. Fronds thin, simply pinnate; pinnce 

 numerous, short-stalked, linear-lanceolate, acuminate, entire or crenulate (3-4' 

 long), those of the fertile frond narrower ; fruit-dots linear, 20-40 each side of 

 the midvein ; indusia slightly convex. Bich woods, W. New Eng. to Wise., 

 and southward along the mountains. Sept. 



11. A. thelypteroides, Michx. (PL 18, fig. 1, 2.) Fronds (2-3 

 high) pinnate ; pinnce deeply pinnatifid, linear-lanceolate (3 - 5' long) ; the lobes 

 oblong, obtuse, minutely toothed, crowded, each bearing 3-6 pairs of oblong 

 fruit-dots, some of them double. Rich woods ; not rare. July - Sept. 



2. ATHYRIUM. Indusium delicate, curved, often crossing the vein, and at- 

 tached to both sides of it, thus becoming reniform, or shaped like a horseshoe. 



12. A. Filix-fCBmina, Bernh. Fronds (1-3 high) ovate-oblong or 

 broadly lanceolate, twice pinnate ; pinnae lanceolate, numerous ; pinnules con- 

 fluent on the secondary rhachis by a narrow margin, oblong and doubly serrate, 

 or elongated and pinnately incised with cut-toothed segments ; fruit-dots short, 

 variously curved, at length confluent. Moist woods ; common and presenting 

 many varying forms. July. (Eu.) 



10. SCOLOPEWDRIUM, Smith. HART'S-TONGUE. (PI. 18.) 



Fruit-dots linear, elongated, almost at right angles to the midrib, contiguous 

 by twos, one on the upper side of one veinlet, and the next on the lower side of 

 the next superior veinlet, thus appearing to have a double indusium opening 

 along the middle. (The ancient Greek name, so called because the numerous 

 parallel lines of fruit resemble the feet of the centipede, or Scolopendra.) 



I. S. VTllgare, Smith. Frond oblong-lanceolate from an auricled-heart- 

 shaped base, entire or wavy-margined (7 -IS' long, 1 -2' wide), bright green. 

 Shaded ravines and under limestone cliffs ; central N. Y. ; also in Canada 

 and Tenn. ; very rare. Aug. (Eu.) 



II. CAMPTOSORTJS, Link. WALKING-LEAF. (PI. 18.) 



Fruit-dots oblong or linear, as in Asplenium, but irregularly scattered on 

 either side of the reticulated veins of the simple frond, those next the midrib 

 single, the outer ones inclined to approximate in pairs (so that their two indu- 

 sia open face to face), or to become confluent at their ends, thus forming crooked 

 lines (whence the name, from KU^TTTOS, bent, anti crwpo's, for fruit-dot.) 



1. C. rhizoph^llus, Link. Fronds evergreen, sub-coriaceous, growing 

 in tufts, spreading or procumbent (4-12' long), gradually narrowed from a 

 cordate or auricled base to a long and slender acumination, which often roots 

 at the end and forms a new plant. Shaded rocks, especially calcareous rocks, 

 N. Eng. to Minn., and southward to Kan. and Ala. The auricles are some- 

 times greatly elongated, and even rooting ; in another form they are lacking, 

 as in the thinner leaved C. Sibiricus. July. 



