FiLiCES. (ferns.) 6G9 



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



cilia of the indiisium lorn/ and in flexed over the sporangia. 



2. W. IlvensiS, R. Brown. Frond ohlomj-lanaolale (2' -6' long by 1 ' wiile), 

 smoothish and green above, thickly clothed underneath as well as the stal/c with 

 rusty bristle-like clinff, pinnate ; the pinnai crowded, oblong, obtuse, sessile, piri- 

 natcly parted, tite numerous crowdtd sH/menIs oblony, obtuse, obscurely crenate, 

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

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

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



3. W. glabella, R. Brown. Smooth and naked throiiyhout ; 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. (Eu.) 



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



4. W. Oregana, D. C. Eaton. Smooth; with 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 nccklace-like-jointcd cilia. — Crevices of 

 rocks, south shore of Lake Superior {Bobbins), and westward. 



17. DICKSONIA, L'Her. Dicksonia. (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 pinnai 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. (D. pilosiiiscula, Willd. 

 Nephrodium punctilobulum, Michx. Dennstcedtia, Moore. Sitolubium, ./. Smith.) 

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



18. SCELIZMA, Smith. Scuiz.ea. (PI. 10.) 



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 a-^l^<x>, to split). 



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

 tortuous ; the fertile ones etjually slender {\" wide), but taller (."' - 4' high), and 

 bearing at the top the fertile appendage, consisting of about 5 paii's of crowded 



