FILICES. (ferns.) 6G9 



* Stipes obscurely jointed near the base ; the withered fronds falling away at the joint : 



cilia of the indusium long and infiexed over the sporangia. 



2. W. Ilvensis, K. Brown. Frond oblong-lanceolate (2' -6' long by 1 ' wide), 

 smoothish and green above, thickly clothed underneath as well as the stalk with 

 rusty bristle-like chaff, pinnate ; the pinna; crowded, oblong, obtuse, sessile, pin- 

 natelv parted, the numerous crowded segments oblong, obtuse, obscurely crenate, 

 almost coriaceous ; the fruit-dots near the margin, somewhat confluent when 

 old. (Xephrodium rufidulum, Michx.) — Exposed rocks : common, especially 

 northward, and southward in the Alleghanies. June. (Eu.) 



3. W. glabella, It. Brown. Smooth and naked throughout; frond linear 

 (2' -5' high), pinnate; pinnce roundish or ovate, the lower ones rather remote, 

 (2"- 4" long), cut into 3-7 rounded or somewhat wedge-shaped lobes. — Rocks, 

 Little Falls, New York ( Vasey) ; Willoughby Mountain, Vermont ( Wood, C. 

 C. Frost) ; and high northward. 



* * Stipes not jointed: cilia of the indusium very short and hidden by the sporangia. 



4. W. Oregana, Eaton. Smooth throughout; fronds (2' -8' high, 8"- 

 12" wide) elliptical-lanceolate, pinnate, the fertile ones tallest ; pinnae triangular- 

 oblong, obtuse, pinnatifid ; segments oblong or ovate, obtuse, finely toothed, 

 and in larger fronds incised ; fruit-dots near the margin ; indusium very small, 

 divided almost to the centre into a few necklace-like-jointed cilia. — Crevices of 

 rocks, south shore of Lake Superior (Robbins), and westward. 



17. DICKSONIA, L'Her. Dicksoxia. (PI. 17.) 



Fruit-dots small, globular, marginal, each placed on the apex of a free vein 

 or fork ; the sporangia borne on an elevated globular receptacle, enclosed in a 

 membranaceous cup-shaped indusium which is open at the top, and on the outer 

 side partly adherent to a reflexed toothlet of the frond. (Named for James 

 Dickson, an English Cryptogamic botanist.) 



1. D. punctilobula, Kunze. Minutely glandular and hairy (2° -3° 

 high) ; fronds ovate-lanceolate and pointed in outline, pale green, very thin, with 

 strong chaffless stalks rising from slender extensively creeping naked rootstocks, 

 mostly bipinnate ; primary pinnae lanceolate, pointed, the secondary pinnatifid 

 into oblong and obtuse cut-toothed lobes ; fruit-dots minute, each on a recurved 

 toothlet, usually one at the upper margin of each lobe. (I), pilosiuscula, Willd. 

 Nephrodium punctilobulum, Michx. Dennstredtia, Moore. Sitolobium, J. Smith.) 

 — Moist, rather shady places : very common : pleasantly odorous. July. 



18. SCHIZJ1A, Smith. Schizjea. (PI. 19.) 



Sporangia large, ovoid, striate-rayed at the apex, opening by a longitudinal 

 cleft, naked, vertically sessile in a double row along the single vein of the nar- 

 row divisions of the pinnate (or radiate) fertile appendages to the slender and 

 simply linear, or (in foreign species) fan-shaped or dichotomously many-cleft 

 fronds (whence the name, from cr^i^co, to split). 



1. S. pusilla, Pursh. Sterile fronds linear, very slender, flattened and 

 tortuous ; the fertile ones equally slender (]" wide), but taller (3' - 4' high), and 

 bearing at the top the fertile appendage, consisting of about 5 pairs of crowded 



