6(4). Costae, costules and veins above glabrous, or with very thin short hairs 

 mostly less than 0.2 mm. long; lamina above eglandular; a 

 few very narrow scales 1-3 mm. long persistent on the rachis and 



sometimes on the costae below; sori submarginal on the veins 



6. T. ovata var. Lindheimeri. 



6. Costae, costules and often veins above with at least a few rather stout hairs 



mostly greater than 0.3 mm. long; lamina above often with a few 

 minute glands; scales absent on the rachis and costae below; sori 

 medial to submarginal on the veins (7) 



7(6). One or two pairs of pinnae below somewhat reduced; rhizome short- 

 creeping, sometimes appearing suberect; venation variable (even on 

 the same frond), from anastomosing with a short excurrent vein 

 to connivent at the sinus; lamina above often somewhat hairy; 

 veins above always with stout hairs many of which are greater 

 than 0.4 mm. long 5. T. quadrangularis var. versicolor. 



7. Lowermost pinnae usually not reduced; rhizome short-creeping to frequently 



long-creeping; veins connivent at the sinus or the distal one of each 

 pair meeting the margin slightly above the sinus; lamina above 

 glabrous or sparsely hairy; veins above with or without long stout 

 hairs 7. T. normalis. 



1. Thelypteris Torresiana (Gaudich.) Alston. Fig. 18. 



Fronds clustered on a stout rhizome, to 2 dm. tall or more; rhizome scales 

 linear-lanceolate, acuminate-attenuate, castaneous. long-ciliate, to about 8 mm. 

 long; stipes slender to stoutish, stramineous, to 6 dm. long, scaly at base, glabrous 

 to sparingly setose; blades deltoid-ovate to triangular-lanceolate, acuminate, bi- 

 pinnate-pinnatifid, membranous, setaceous with silvery-white hairs, to 9 dm. long 

 and 4 dm. wide; pinnae triangular-lanceolate to narrowly elliptic, acuminate, 

 pinnate; pinnules sessile, lanceolate, acute to acuminate, deeply pinnatifid, con- 

 fluent at apex, to about 5 cm. long and 1.5 cm. wide; ultimate segments rounded, 

 coarsely toothed, about 2 mm. wide; sori solitary at the anterior margin of a 

 tooth, 1 to 6 per segment; indusia obsolete, early fugacious. 



Along streams in pinelands, in swamps, marshes and on moist wooded banks, 

 in e. Tex. (Newton and Hardin cos.); nat. of Asia and adj. I., escaped from cult, 

 and more or less established in cen. peninsula Fla., Ala. to Tex. and trop. Am. 



2. Thelypteris hexagonoptera (Michx.) Weath. Broad beech fern. Fig. 19. 

 Fronds distant, erect, arising at 5-15 mm. intervals on a slender creeping 



rhizome, to about 8 dm. tall; rhizome scales light-brown, ovate-lanceolate to linear- 

 lanceolate, often long-ciliolate, 3-5 mm. long; stipes weak, slender, stramineous 

 or greenish, 2—4.5 dm. long; blades broadly triangular, acute to acuminate, bi- 

 pinnatifid, 15-38 cm. long, about as broad as long or broader, slightly pubes- 

 cent and frequently glandular on lower surface; rachis irregularly winged through- 

 out; primary segments elliptic-lanceolate, acuminate, tapering at both ends, 

 pinnatifid, with the lower usually larger pair of segments directed downward and 

 away from the rachis at a different angle from the upper segments; ultimate seg- 

 ments obliquely oblong, obtuse, subentire to deeply crenate or sometimes nearly 

 pinnatifid; sori naked, mostly near the margin. 



On sandy-loamy wooded slopes and in ravines along streams, in open rocky 

 thickets, and on the edge of low swampy woods and bogs, rare in e. Okla. and in 

 the e. Tex. Timber Belt; from Fla. to e. Tex. and Okla.. n. to Que. and Minn. 



3. Thelypteris palustris Schott var. Haleana Fern. Southern marsh fern. Figs. 



19 and 20. 

 Fronds erect from a slender widely creeping rhizome, to 12 dm. tall; rhizomes 

 blackish; stipes slender, glabrous or nearly so, stramineous above, purplish toward 

 base, about as long as the blade; blades lanceolate to elliptic-lanceolate, short- 



72 



