582 CRYPTOGAMIA FILICES 



. Fronds 12 to 13 inches long, and 1 to 6 or 8 inches wide, in their outline ohlong 1 - 

 lanceolate, acuminate, pinnate, slender and rather flaccid, smoothish, and of a 

 palish glaucous-green color ; leaflets 2 to 5 inches long, and half an inch to 3 quar- 

 ters wide, oblong-lanceolate in their outline, acuminate, sessile, distinct and rather 

 distant on the common rachis, of a thinnish texture, pinnatifid,— the acuminatum 

 crcnate serrate ; segments 2 to 4 lines long, and 2 to 3 lines wide, linear-oblong, ob- 

 tuse, obscurely crenate-serrate, or denticulate ; common rachis slender, and, with 

 the midrib of the leaflets, slightly pubescent on the upper side ; stipe 6 to 10 inches 

 long, slender and weak, pale straw-color,striatc-sulcate on the upper side, slightly 

 chaflfy, or membranaceously pilose. Sori linear, acule on each end, arranged in 

 two rows, one on each side of the midrib of the segments, the outer ends divcrgine. 

 llab. Moist woodlands ; shaded banks of streams : frequent. Fr. July. 



f t t t Frond sub-bi pinnate. 



5, A. Ruta muraria, L. Frond bipinnate at base, simply pinnate 

 at summit; leaflets small, petiolatc, rhomboid-cuneatc, the upper half 

 obtusely denticulate. Becky hot. p. 453. 



Wall-rue Asplenium. 



Fronds 1 to 2 inches long, and half an inch to an inch wide, spreading, smooth, 

 dingy green, bipinnately dissected at base, or decompound, with the divisions 

 petiolatc, alternate, and usually bearing the leaflets in threes,— simjjy pinnate at 

 the summit; leaflets 2 to 4 lines long, and 2 to 3 lines wide, more or less rhomboid, 

 rather obtuse, dentate above the middle (sometimes partially lobed), entire below 

 i he middle, and cuneately tapering to a short flat petiole ; stipe 1 to 2 inches long, 

 slender, flat, smooth. Sori linear-oblong, slightly oblique, finally confluent, and 

 of a dark ferruginous color. 



llab. Limestone rocks ; near Brooke's Mill : not common. Fr. July. 



Obs. Collected by D. Townsbnd, Esq. Two or three additional species arc 

 enumerated in the U. States. 



465. PTERIS. L. J\*utt. Gen. 824. 

 [The Greek name for a fern— from Pteryx, or Pteron, a plume, or feather.] 



Sori marginal, continuous, linear. Indurium formed of the indexed 

 margin of the frond, often dilated into a membrane, opening along the 

 inner side. 



1. P. atropurpurea, L. Frond pinnate, or sub-bipinnatc ; lower 

 divisions ternate, or pinnate; leaflets lance-oblong, obtuse, entire, ob- 

 liquely truncate or subcordate at base. Beck, Bot. p. 454. 



Dark-purple Pteris. 



Fronds 3 or 4 to 6 or 8 inches long, and 1 to 2 or 3 and sometimes 4 inches wide 

 across the lower divisions, somewhat bipinnate, the lower divisions being ter- 

 nate, or odd-pinnate by 5's or Vw\ leaflets 1 fourth of an inch to an inch or inch 

 and quarter long, and 1 to 4 lines wide, subsessile (the terminal one longer and 

 petiolate), varying from ovate-oblong to oval, lance-oblong, and linear, obtuse, 

 smooth, greyish-green, often punctate beneath, with the margin entire and reflexed 

 —the lower leaflets occasionally subhastate, or auriculately produced, on one or 

 both sides, at base ; stipe 2 to 4 or 5 inches long, slender, terete, rather rigid (often 

 numerous from the same root, with a dense tuft of tawny-ferruginous chaffy hairs 

 at base), and, with the common rachis, roughish-pubescent, dark purple. Sori 

 conspicuous, linear and marginal,— the indicium apparently a membranaceous 



