POLYPODIACEAE 13 



sori oblong, borne about midway between the midrib and the margin of the blade, nearly 

 or quite straight. [A. parvulum Mart. & Gal., not Hook.] 



Often on limestone, Virginia to Missouri, Florida, Texas, New Mexico and Mexico. 



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

 petioles purplish brown and shining, 2.5-10 cm. long ; blades linear, 2-4 cm. long, firm, 

 pinnate, the rachis chestnut-brown ; leaflets 20-40 pairs, lanceolate, subfalcate, alternate 

 or partly so, sessile, crenate, serrate or incised, auricled on the upper side at the base and 

 occasionally also on the lower ; lower leaflets gradually smaller and oblong, or triangular : 

 sori 8-12 on each side of the midrib, crowded at maturity. [A. ebeneum Ait.] 



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



6. Asplenium Trichomanes L. Kootstock short, nearly erect, with blackish scales. 

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

 blades linear in outline, 7-20 cm. long, rather rigid, pinnate, evergreen ; leaflets oval or 

 roundish oblong, inequilateral, cuneate at the base, their margins slightly crenate ; sori 

 3-6 on each side of the forking and evanescent midrib, short, narrowed at both ends. 



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



7. Asplenium dentatum L. Petioles tufted, 5-15 cm. long, naked, blackish below. 

 Fertile leaf-blades 5-7.5 cm. long, with 6-8 pairs of stalked oblong or rhombic leaflets, the 

 lower side truncate with a curve, the outer edge irregularly crenate ; sterile leaves similar 

 but with shorter petioles : rachis naked : sori copious, in parallel rows. 



In sandy soil, South Carolina to Florida. Also in the West Indies. 



8. Asplenium angustifolium Michx. Rootstock stout. Fertile leaves usually taller 

 than the sterile. Petioles in a crown, chaffless, or merely scaly at the base, 2-3 dm. long, 

 brownish or greenish above ; leaf-blades lanceolate, 3-8 dm. long, pinnate ; leaflets linear- 

 lanceolate or those of sterile leaves lanceolate, in 20-30 pairs, acuminate, entire or crenulate, 

 obtuse or truncate ajt the base : sori 20-30 on each side of the midrib, linear, crowded. 



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



9. Asplenium firmum Kunze. Petioles 10-20 cm. tall, naked, grayish. Leaf-blades 

 15-30 cm. long ; leaflets oblong-lanceolate, 12-20 pairs, blunt-pointed, minutely crenulate, 

 the upper margin abruptly narrowed at the base, the lower obliquely truncate : s'ori short, 

 not reaching either margin or midrib. 



In caverns, peninsular Florida. Also in the West Indies. 



10. Asplenium Ruta-muraria L. Rootstock ascending. Leaves tufted ; petioles 

 naked, green, 5-7 cm. long ; blades ovate or deltoid-ovate, 5-12 cm. long, glabrous, ever- 

 green, 2-3-pinnate, or pinnatifid above ; leaflets stalked, rhombic or obovate, mostly obtuse, 

 dentate or incised, cuneate at the base ; veins flabellate : sori few, linear-oblong, confluent 

 when mature and nearly covering the leaflet : indusia membranous and delicate. 



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

 Also in Europe, Asia and northern Africa. 



11. Asplenium montanum Willd. Rootstock chaffy at the summit. Leaves tufted ; 

 petioles naked, slender, blackish at the base, 5-7 cm. long ; blades 5-20 cm. long, ovate- 

 lanceolate in outline, acuminate, rather firm, 1-2-pinnate ; lower leaflets longest, pinnate or 

 pinnatifid, the lobes or segments ovate or oblong ; upper less divided, merely toothed or in- 

 cised ; veins obscure : sori linear^oblong, short, the lower ones sometimes double. 



On rocks, Connecticut to Ohio and Arkansas, and in the mountains to Georgia and Alabama. 



12. Asplenium Bradley i D. C. Eaton. Rootstock chaffy with brown scales. Leaves 

 tufted ; petioles slender, 5-7 cm. long, chestnut-brown ; blades oblong-lanceolate or oblong, 

 acuminate, not narrowed at the base, with 8-12 pairs of short-stalked or sessile oblong- 

 ovate leaflets ; the lower again pinnatifid or pinnate, with oblong obtuse lobes or pinnules, 

 which are toothed at the apex, the upper pinnatifid with dentate or nearly entire lobes : 

 rachis brown : sori near the midrib, covered with the narrow indusia until mature. 



On rocks, often preferring limestone, New York to Illinois and Missouri, south to middle Georgia, 

 Alabama and Arkansas. 



13. Asplenium cicutarium Sw. Petioles greenish, tufted, 10-20 cm. long, naked. 

 Leaf- blades 15-38 cm. long, with 10-15 pairs of horizontal leaflets, the lower ones 5-7.5 

 cm. long, parted into linear or oblong segments which are once or twice cleft at the apex : 

 rachis compressed and often winged : sori mainly in 2 rows. 



In swamps, Sumter County, Florida. Also in tropical America. 



14. Asplenium myriophyllum Mett. Petioles tufted, 5-15 cm. long. Leaf -blades 

 lanceolate, 8-30 cm. long, 2-3-pinnatifid ; segments entire, or 2-3-lobed, each bearing a 

 single vein and a sorus. 



On rocks in sink-holes, peninsular Florida. Also in tropical America. A form with narrowly 

 linear leaf-blades 1.8-2.5 cm. wide, and 7-8-lobed widely ascending leaflets, is known as A. myriophyllum 

 Biscaynednum D. C. Eaton. 



