(FERNS.) 687 



2. A. K"oveboric6nse, Swartz. Fronds pinnate, lanceolate in outline, 

 tapering both ways from the middle ; pinnae lanceolate, the lowest 2 or more 

 pairs gradually shorter and dejlexed ; lobes flat, oblong, basal ones often en- 

 larged and incised ; veins simple, or forked in the basal lobes; fruit-dots dis- 

 tinct, near the margin ; indusium minute, the margin glandulif erous. Swamps 

 and moist thickets ; common. July. Frond pale green, delicate and mem- 

 branaceous, hairy beneath along the midribs and veins. 



* # Veins, at least the lowest, more than once forked or somewhat pinnately 

 branching ; fruit-bearing veinlets often obscure or vanishing above the fruit- 

 dot ; fronds, at least the sterile ones, often evergreen ; stalks and apex oj 

 the thickened rootstock scaly or chaffy, and often the main rhachis also. 

 i- Fronds small, pinnate ; pinnce pinnatijid ; indusia very large, persistent. 



3. A. fragrans, Swartz. Fronds (4 -12' high) glandular and aromatic, 

 narrowly lanceolate, with linear-oblong pinnately-parted pinnae ; their crowded 

 divisions (2" long) oblong, obtuse, toothed or nearly entire, nearly covered be- 

 neath with the very large thin imbricated indusia, which are orbicular with a 

 narrow sinus, the margin sparingly glandulif erous and often ragged. On 

 rocks, especially near waterfalls, mountains of northern New Eng., west and 

 northward. Rootstock stout, nearly erect, densely chaffy, as are the crowded 

 stipes and rhachis. (Asia, and barely reaching S. E. Eu.) 



*- H Large (1 -2^ high), the fronds mostly twice pinnate with variously toothed 

 and incised pinnules ; indusia rather small, shrivelled in age, or deciduous. 



4. A. Spinul6sum, Swartz. Stipes with a few pale-brown deciduous 

 scales ; frond ovate-lanceolate, twice pinnate ; pinnce, oblique to the rhachis, 

 elongated-triangular, the lower pairs broadly triangular; pinnules set obliquely 

 on the midribs, connected by a very narrow wing, oblong, acute, incisely ser- 

 rate or pinnatifid with spinulosely-toothed lobes ; indusium smooth and without 

 marginal glands. In damp woods, New Eng. to Ky., and northward. July. 



The common European type, rare in North America. (Eu.) 



Var. intermedium, D. C. Eaton. Scales of the stipe few, brown with 

 a darker centre ; frond broadly oblong-ovate, twice or often thrice pinnate ; 

 pinnce spreading, oblong-lanceolate, the lower unequally triangular-ovate ; pin- 

 nules crowded, ovate-oblong, spreading, pinnately divided ; the oblong lobes 

 spinulose-toothed at the apex; margin of the indusium denticulate and beset 

 with minute stalked glands. Woods, everywhere. 



Var. dilatatum, Hook. Scales of the stipe large, brown with a dark cen- 

 tre ; frond broader, ovate or triangular-ovate in outline, oftenest thrice pinnate ; 

 pinnules lance-oblong, the lowest often much elongated ; indusium (in the 

 North American plant) smooth and naked. A dwarf state, fruiting when 

 only 5-8' high, answers to var. dumetorum. N. New Eng. to Minn., chiefly 

 in mountain woods, and northward. (Eu.) 



5. A. Bodttii, Tuckerman. Scales of the stipe pale-brown; fronds (1-2^ 

 long) elongated-lanceolate in outline, somewhat narrowed at base ; lowest pin- 

 nae triangular-ovate, the upper longer and narrower ; pinnules oblong-ovate, 

 sharply spinulose-serrate or the lower pinnatifid; indusium minutely glandular. 

 (A. spinulosum, var. Boottii, of last ed. A. cristatum, var. uliginosum, Milde.) 



Wet thickets and about ponds, New Eng. to Del. and Minn. July. Ster- 

 ile fronds much smaller and simpler than the fertile. (Eu.) 



