POLYPODIACEAE 15 



long, firm, tapering to a slender acuminate apex, pinnatifid, or commonly pinnate 

 below, the segments lanceolate to deltoid-ovate, irregular. 



On limestone, Vermont to Missouri, Virginia and Alabama. Kare. 



4. Asplenium Trichdmanes L. Eootstock short, nearly erect, with blackish 



scales. Leaves densely tufted, numerous; petioles 2.5-12 cm. long, purplish brown, 



shining; blades linear, 7-20 cm. long, pinnate, evergreen; leaflets oval or roundish 



oblong, inequilateral, cuneate at the base, the margins slightly crenate; sori 3-6 pairs, 



short. 



On rocks, preferring limestone, nearly throughout North America. Also in Europe 

 and Asia. 



5. Asplenium platyneuron (L.) Oakes. Eootstock short. Leaves tufted; 

 petioles purplish brown, shining, 2.5-10 cm. long; fertile blades linear-oblanceolate, 

 2-4 dm. long, firm, pinnate, the rachis chestnut-brown; leaflets 20-40 pairs, lanceo- 

 late, subfalcate, alternate or partly so, sessile, crenate, serrate or incised, auricled on 

 the upper side at the base and sometimes below; lower leaflets gradually smaller and 

 oblong, or triangular: sori 8^-12 pairs, crowded. [A. ebeneum Ait.] 



On rocks and shaded slopes, Maine and Ontario to Colorado, south to Texas and the 

 Gulf States. 



6. Asplenium resiliens Kunze. Eootstock short, with a conspicuous tuft of 

 long filiform blackish scales. Leaves tufted; petioles blackish and shining, 2.5-7 cm, 

 long; blades firm, linear-oblong or linear-oblanceolate, 7-25 cm. long, 1-pinnate; 

 leaflets 4-12 mm. long, mostly opposite, oblong, obtuse, entire or crenulate, auricled 

 on the upper side, sessile, the middle ones the longest, the lower gradually shorter, 

 deltoid-cordate, reflexed: rachis dark brown or black: sori oblong, medial or nearer the 

 margin, straight or nearly so. [A. parvulum Mart. & Gal., not Hook.] 



On rocks, Virginia to Missouri, Florida and New Mexico. Also in Mexico and Jamaica. 



7. Asplenium muticum Gilbert. Eootstock short, with an inconspicuous cover- 

 ing of small blackish linear-lanceolate scales. Leaves tufted; petioles dark castaneous 

 or blackish, 1.5-7 cm. long, narrowly alate; blades 1-3 dm. long, 1-2 cm. broad, 

 linear or broadest above the middle, tapering in both directions, pinnate; leaflets 

 oblong, obtuse, membranous, more or less auriculate above, cuneate at the base below, 

 elsewhere crenate-serrate; lower leaflets gradually smaller, the lowest fan-shaped, 

 often vestigial; sori linear-oblong, oblique, close to the midrib. 



On moist shaded rocks, southern Florida. Also in the Bermudas. 



8. Asplenium pycnocdrpon Spreng. Eootstock stoutish, creeping. Leaves in a 

 crown, the fertile usually taller than the sterile; petioles 2-3 dm. long, slightly scaly 

 at the brownish base, green above; sterile blades lanceolate to lanceolate-ovate, 3-8 

 dm. long, pinnate; leaflets linear-oblong, attenuate, entire or crenulate, obtuse or 

 truncate at the base, those of the fertile blades narrower; sori 20-40 pairs, linear, 

 crowded. [A. angustifolium Michx. Not Jacq.] 



In moist or rich, often rocky woods, Quebec to Wisconsin, Virginia, Georgia and Alabama. 



9. Asplenium abscissum Willd. Eootstock erect or decumbent, 1-3 cm. long. 

 Leaves several, 1.5-3.5 dm. long; petioles 8-20 em. long, smooth, grayish brown or 

 greenish; blades 7-20 cm. long, usually deltoid or deltoid-ovate, acuminate; leaflets 

 8-20 pairs, oblong-lanceolate, obtuse or acute, often attenuate, at the base strongly 

 inequilateral, excised below, the margins crenate-serrate, usually doubly so; sori 

 medial, or nearer the midvein, linear-oblong, conspicuous. [A. firmum Kunze.] 



In moist rocky woods and caverns, peninsular Florida. Also in tropical America. 



10. Asplenium dentatum L. Eootstock short. Leaves numerous, tufted, 1-3.5 

 dm. long. Fertile leaves surpassing the more leafy sterile ones; petioles 5-15 em. 

 long, naked, dark below; blades 5-25 cm. long, oblong to linear; leaflets 5-12 pairs, 

 stalked, oblong, rhombic, suborbicular, or often narrowly wedge-shaped, at the base 

 very narrowly cuneate and entire, elsewhere dentate or crenate : sori close, very oblique. 



Usually on limestone. South Carolina and Florida. Also in tropical America. 



11. Asplenium Ruta-muraria L. Eootstock short. Leaves tufted; petioles 

 naked, green, 5-7 cm. long; blades rhombic to deltoid-ovate, 5-12 cm. long, glabrous, 

 evergreen, 2-3-pinnate, or pinnatifid above; leaflets stalked, variable, commonly rhom- 

 bic or obovate, mostly obtuse, dentate or incised, cuneate ; veins flabellate : sori few, 

 linear-oblong, strongly confluent at maturity: indusia membranous, delicate. 



On limestone, Vermont to Michigan and Missouri, south to Connecticut, Alabama and 

 Arkansas. Also in Europe, Asia and northern Africa. 



12. Asplenium mont^num Willd. Eootstock chaflfy at the summit. Leaves 

 tufted; petioles naked, slender, dark brown at the base, 5-11 cm. long; blades del- 



