Platyloma. FILICES. 489 



Stipe 2-4 inches long, dark purple, often tortuous, terete, slender, somewhat pubescent 

 with roughish hairs. Frond 4-8 inches long, of a dull grayish-green color, rather coriaceous, 

 smooth ; the lower divisions often pinnate, with 3, 5 or 7 segments ; the lowest segments 

 sometimes hastate or auriculate, revolute when young. Sori continuous, forming a prominent 

 margin. Involucre membranaceous, slightly crenate. 



Limestone rocks : not common. Fr. June - July. The segments of the barren fronds 

 are rather broader than those of the fertile ones. 



7. DOODIA. R. Br. prodr. p. 151 ; Presl, Pterid. p. 99. t. 3. /. 18 ; /. Smith, I. c. no. 65. 



DOODIA, 

 [In memory of Samuel Doodt, one of the first investigators of Bristish cryptogamous plants.] 



Sori oblong or linear, straight or curved, distinct, parallel and near to the midrib, produced 

 on the transverse anastomosing veins. Involucre flat, lateral ; the free margin opening 

 inwards. — Frond pinnatifid or pinnate : pinnas sometimes pinnatifid ; the margin spinulose- 

 serrulate. Veins forked ; the venules anastomosing near their base and forming large 

 areolae, free toward the margin. 



I. DooDiA ViRGiNiCA, Pres/. Virginian Doodia. 



Fronds pinnate, fertile and sterile similar; the pinnas pinnatifid, lanceolate. — Presl, I. c; 

 J. Smith, I. c. Woodwardia Virginica, Swartz, syn. Fil. ; Willd. sp. 5. p. 418 ; Pursh, 

 fi. 2. p. 670 ; Bigel. fl. Host. p. 394 ; Torr. compend. p. 384 ; Beck, bot. p. 454. W. 

 Banisteriana, Michx. fl. 2. p. 263. Blechnum Virginicum, Linn. mant. p. 307. B. Caro- 

 linianum, Walt. fl. Car. p. 257. 



About 2 feet high, growing in tufts, smooth ; the stipe and rachis varying from light to 

 dark brown. Frond oblong-lanceolate in the outline, of a thickish texture : pinnae numerous, 

 opposite or alternate, 2-3 inches long : segments oblong, rather obtuse, slightly incurved ; 

 the margin serrulate and somewhat cartilaginous. Veins of the segments forking near the 

 base, where they anastomose with each other and with the veins of the contiguous segments, 

 and then proceed directly to the margin. On the anastomosing veins, which are near the 

 midrib, the sori are situated. These are linear, and form a row on each side of the midrib of 

 the pinna and segments ; when old, they are somewhat confluent. 



Swamps, Long Island, &c. : rare in the interior of the State. Fr. July. The genus 

 Doodia differs from Woodwardia in its more compound anastomosing veins and revolute 

 vaulted involucre. 



[Flora — Vol. 2.J 62 



