88 Our Native Fims. 



or again pinnate ; upper pinnae smaller, pinnatifid, lobed, or en- 

 tire ; sori copious forming submarginal rows around the segments. 

 Minn. II. 



XIX. ASPIDIUM, Swz. Shield-fern, Wood-fern. 



Sori round borne on the back or rarely at the apex of the veins. 

 Indusium flat or flattish, orbicular and peltate at the centre, or 

 cordato-reniform and fixed either centrally or at the sinus. Stipe 

 continuous with the rhizoma. 



I I. NEPHRODIUM, Rich. (DRYOPTERIS, Adanson). In- 

 dusium cordato-reniform or orbicular with a narrow sinus. 



* Texture thin m.embranous, veins simple or once forked, frotids 

 bipinnatifid. 



\ Lowest pinna gradually reduced to mere lobes. 



1. A. Noveboracense,* Swz. Rhizoma slender, creeping; 

 fronds i° — 2° long, 4' — 6' broad, lanceolate, tapering both ways 

 from the middle ; pinnte lanceolate, the lowest two or more pairs 

 gradually shorter and deflexed, those of the barren frond broader ; 

 segments flat, oblong, basal ones often enlarged ; veins simple or 

 forked in basal lobes ; sori distinct, near the margin ; indusium 

 minute, the margin glanduliferous. N. C, Ky., and Northern 

 U. S. III. 



2. A. conterminum, Willd., var: strigosum, Eaton. Rhizoma 

 stout, erect, often extending a foot above ground, bearing a crown 

 of fronds; stipes very short, narrowly wing-margined at the base; 

 fronds 1° — 4° long, lanceolate in outline, caudate-acuminate, much 

 narrowed at the base, somewhat rigid, pinnate ; pinnae sessile, nar- 

 rowly lanceolate from a broader base, acuminate, deeply pinna- 

 tifid into oblong Obliquely sub-falcate obtuse segments, under 

 surface copiously dotted with resinous globules ; veins free, sim- 

 ple ; sori near the margin ; indusium reniform, minute, glandular, 

 somewhat pilose, evanescent. Fla. 1880. VI. 



3. A. Nevadense,* D. C. Eaton. Rhizoma creeping, densely 

 covered with the persistent bases of former stalks ; fronds in a 

 crown, i^° — 3° high, lanceolate; pinnae linear-lanceolate from a 

 broad base, deeply pinnatifid, the lower pairs distant and gradu- 

 ally reduced to mere auricles; segments crowded, oblong, slightly 

 hairy on the veins beneath, and sprinkled with minute resinous 

 particles; veins about seven pairs to a lobe; sori close to the 

 margin ; indusium minute furnished with a few dark colored mar- 

 ginal glands and bearing several straight jointed hairs on the 

 upper surface; Cal. IV. 



