662 FILICES. (FERNS.) 



< +- Fronds once or twice pinnate : pinnae, incised. 



5. A. montamim, Willd. Fronds (2' - 5' high), ovate-lanceolate, pinnate : 

 the ovate pinnce 3-7 '-parted (or the upper barely cleft) and cut-toothed; fruit-dots 

 very short, the basal ones sometimes double. Cliffs in the Alleghanies, Penn- 

 sylvania (Mr. Lea, Prof. Porter), to Virginia and southward. July. Rhachis 

 green, broad and flat : stipe brown at the base. 



6. A. Ruta-muraria, L. Fronds (2' -4' long) ovate in outline, 2-3-pin- 

 nate below, simply pinnate above ; the Jew divisions rhombic-wedge-shaped, toothed or 

 incised at the apex; veins forking, diverging from the base; fruit-dots few, elon- 

 gated, soou confluent. Limestone cliffs, Vermont to Michigan, Virginia, and 

 southward along the mountains : scarce. July. (Eu.) 



# # Indusium slightly curved, strongly convex, thickish : fruit-dots very numerous and 



crowded. (Fronds tall, simply pinnate, decaying in autumn.) 



7. A. angUStifblium, Michx. Fronds (2 -3 high) thin, simply pinnate ; 

 pinnce numerous, short-stalked, linear-lanceolate, acuminate, entire or crenulate 

 (3' -4' long), thoseof the fertile frond narrower; fruit-dots linear, 20-40 each side 

 the midvein. Rich woods, W. New England to Wisconsin, and southward 

 along the mountains. Sept. 



* * * Lower fruit-dots single, those towards the ends of pinnce double : indusium 

 straight, slightly convex, thinnish. (Fronds tall and ample, decaying in autumn.) 



8. A. thelypteroides, Michx. Fronds (2 -3 high) pinnate; pinnce 

 deeply pinnatiftd, linear-lanceolate (3' -5' long); the lobes oblong, obtuse, mi- 

 nutely toothed, crowded, each bearing 3-6 pairs of oblong fruit-dots. Rich 

 woods : not rare. July - Sept. 



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

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



9. A. Filix-fOBmina, Bernh. Fronds (l-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. (Aspidium Filix-fceinina & A. aspleni- 

 oides, Swartz.) A narrow form is Aspidum angiistum, Willd. Moist 

 woods : common, and very variable. July. (Eu.) 



9. SCOLOPENDBIUM, Smith. HART'S-TONGUE. (PL 17.) 



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.) 



1. S. Vlllgare, Smith. Frond oblong-lanceolate from an auricled-heart- 

 shaped base, entire or wavy-margined (7' -18' long, 1'- 2' wide), bright green. 

 (S. officinarum, Swartz, a later name.) Shaded ravines and under limestone 

 cliffs, Chittenango Falls, and near Jamesville, &c., Onondaga Co., New York, 

 Pursh, W. Cooper, Lewis Foote, J. A. Paine : also in Canada West. (For a full 

 account of stations, see Silliman's Journal for May and September, 1 866. (Eu. ) 



