125 



forked ; sori copious, terminal on the short anterior hranch, contiguous 

 in two long bright yellow rows that occupy nearly all the space between 

 the dark thread-like midrib and margins : — P. elastieum, Rich, Eat, 

 Ferns N. Am. p. 63. P. Pulchrum, M, & Gf, P. Schkuhri, Raddi. 



Common on open rocks and banks at nearly all elevations up to 

 5,00()ft , alt. variable in size but well marked from its allies by its copious 

 horizontal close and very narrow pinnne, and long rows of conspicuous 

 yellow sori. The substance is so elastical that in dry weather the 

 fronds curl up, expanding again with rain. The sori do not reach 

 quite to the rachis, so that there is a naked band down the centra of 

 the frond, which in many cases gradually broadens toward the base. 

 PI. Fib t, 89 (P. Pliimula, Willd.) is either this or taxi folium. 



38. P. pectinatum, Linn. — Rootstock strong, short-creeping, densely 

 clothed with small dark-brown subulate scales ; stipites contiguous and 

 subtufted, or apart, strong or slender, usually dark coloured, puberu- 

 lous or slightly ciliate, often slightly margined, rarely a span long; 

 fronds 1-2 ft. 1. 2-5 in. w. oblong-lanceolate, pinnatifid almost to the 

 dark-coloured puberulous, naked or slightly ciliate rachis, elastico- 

 chartaceous dull green nearly or quite naked, gradually or more or 

 less abruptly reduced at the base ; pinnaa horizontal, straight very nu- 

 merous, linear-ligulate, acute or bluntish at the end, close, but broad- 

 ening to and rather dilated at the base the sinus sharp or rounded ad- 

 nate confluent and nearly equilateral 1-2^ in. 1. 2J-4 li. w., the inferior 

 reduced and decurrent through deltoid to broad shallow scallop-shaped 

 lobes J-J in. w. and less than a line deep which form a wing to at least 

 the upper part of the stipites ; veins once or twice forked, midrib slen- 

 der, black, wavy toward the end ; sori medial, round, terminal on the 

 lowest anterior veinlet, l-L^ li. apart in the rows : — PI. Fil t. 83., Eat. 

 Ferns N. Am. PI. 42. 



a. var. caespitosum : — Rootstock erect, or oblique, stipites tufted, 

 1-3 in. 1. dark; fronds erect, few, 1^-1^ ft. 1. 2.2^ in. w., blunt or 

 rounded, rachis and ribs puberulous ; veins once-forked, short of the 

 edge, the anterior fertile conspicuously shorter. 



b. var. Wagnerii rootstock more decidedly woody, % in thick, scales 

 fine and very dark ; fronds 1-1^ ft. 1. 2-3 in. w. ; stipites and rachises 

 slender but stiff ; pinnse blunt or rounded, about 2 li. w. texture mem- 

 branous and elastical, surfaces more decidedly glabrous ; veins usually 

 once forked, the outer branch much curved along the margin to the 

 next one, where it is free or united to a short spur ; sori medial on the 

 shorter anterior branch. — P. Wagnerii, Mett. 



Common at all elevations on open or shady wayside banks, rocks and 

 trees up to 5,000 or 6,000 ft. alt., variable, including three or four 

 distinct forms. It is best marked by its almost or quite naked surface, 

 elastic texture, lower pinnae suddenly or not reduced to auricles and 

 sometimes into a scalloped wing along the stipites, and medial rather 

 small yellow circular sori. The rootstock is repent with the fronds 

 usually contiguous and erecto-drooping. a grows on stones under shade 

 at Old England, at 4,000 ft. altitude. Its roostock is upright or oblique 

 with the fronds tufted at the summit, shuttlecock-like in form ; the 

 rachis freely puberulous, a pellucid plait running from the sinuses to 

 the rachis. This I have gathered also plentifully in Gruiana. b is a 

 slender but stiff plant, with longer wiry stipites and fronds more abrupt- 



