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. Bare. 



4. Asplenium Trichdmanes L. Kootstock 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, subf alcate, 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 mu tic urn 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 pycnocarpon 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 cm. long, smooth, grayish brown or 

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

 &-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 cm. 

 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 montanum Willd. Eootstock chaffy at the summit. Leaves 

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



