396 



ACROGENOUS PLANTS 



Aspidium Thelypteris. Willd. $ Fl. Cestr. ed. 2. p. 577. 



Fronds 6 to 12 inches long, and 3 or 4 inches wide ; pinnae 1 to 2 inches long, 

 subsessile, slightly pubescent; stipe 9 to 15 inches long. Son commencing in 

 small marginal dots, finally confluent, and usually covering the under surface of 

 all the lobes of the frond. 

 Hob. Swamps, and wet thickets : frequent. Fr. July. 



3 I>. NoveboraceilSiS, A. Gray. Fronds oblong-lanceolate ; 



pinnae lance-oblong, pinnatifid, the lobes flat, ciliate; sori never 



confluent. 



Aspidium Noveboracense. Willd. $ Fl. Cestr. ed. 2. p. 677. 



NEW- YORK DRYOPTERIS. 



Fronds 9 to 18 inches long, and 3 to 5 inches wide ; pinnae 2 to 3 inches long, 

 thin and delicate, pale green ; stipe 3 to 6 inches long, slender, channelled above. 

 Sori small, marginal, in 2 rows on each lobe ; the fronds, however, are often sterile. 

 nab. Moist woodlands : frequent. Fr. July. 



ff Veins more than once forked, or somewhat pinnately branching ; stipes cliaffy. 

 * Fronds sub-tripinnate (i.e. the pinnules pinnatijid). 



3* D. intermedia, A. Gray. Fronds ovate-oblong ; pinnae 

 lance-oblong ; pinnules oblong-linear, distinct, incisely pinnatifid, 

 the lobes mucronate. 



Aspidium dilatatum. Fl. Cestr. ed. 2. p. 578. not of Sw. and Willd. 

 INTERMEDIATE DRYOPTERIS. 



Fronds 12 to 20 inches long, and 5 to 8 or 9 inches wide, elliptic-lanceolate In 

 their outline ; pinnae 3 to 5 inches long, and 1 to 2 inches wide ; common rachis 

 somewhat chaffy ; stipe 6 to 15 inches long, clothed with large brownish-tawny 

 chaffy scales. Sori rather large, numerous ; indusium orbicular-reniform, umbili- 

 cate in the centre. 

 Hob. Moist woodlands : frequent. Fr. July. 



* * Fronds bipinnate only, with the pinnules (or sometimes only lobes) merely incised, or 

 tootJied ; stipes somewhat chaffy. 



4. U. cristata, A. Gray. Fronds linear-oblong; pinnae short, 

 triangular-ovate, subcordate at base, deeply pinnatifid ; lobes oblong, 

 obtuse, incised-serrate at apex. 



Aspidium Lancastriense. Fl. Cestr. ed. 2. p. 577. 

 CRESTED DRYOPTERIS. 



Fronds 18 inches to 2 feet long, and 3 or 4 inches wide, smoothish, deep green ; 

 pinnae 1% to 3 inches long, sub-opposite, the lower ones stipitate, the upper 

 ones sessile and confluent : stipe 8 to 12 inches long, rather slender, often smooth- 

 ish, the chaff being deciduous. Sori medium size, distinct, dark-brown, in 2 

 rows, generally confined to the upper half of the frond ; indusium orbicular-reni- 

 form. 

 Hob. Moist woodlands : not very common. Fr. July. 



5. I>. inargllialis, A. Gray. Fronds ovate -oblong ; pinnae 

 lanceolate, broad at base, deeply pinnatifid ; lobes oblong, crenate- 

 serrate, the lower ones nearly distinct; sori marginal. 

 Aspidium marginale. Willd. $ Fl. Cestr. ed. 2. p. 578. 

 MARGINAL DRYOPTERIS. 



Fronds 9 to 15 inches long, and 4 to 6 inches wide ; pinnae 2 to 4 inches long, 

 sub pinnate, the acumination crenate; stipe 4 to 8 inches long, clothed with a 



