52 ENGLISH BOTAN'Y. 



SPECIES I. -LAST RE A THELYPTERIS. Presl. 



Plate 18-48. 



Babenh. Crypt. Vase. Europ. Exsicc. No. 16. 



L. palustris, J. S. Milde, Hist. Fil. p. 266. 



Nephrodium Thelypteris, Desv. Hook. fil. Stud. Fl. p. 466. Hook. & Bak. Syn. Fil. 



ed. ii. p. 271. 

 Aspidium Thelypteris, Schwartz. 8m. Eng. Fl. Vol. IV. p. 285. Fries, Sunim. Veg. 



Scand. p. 82. Babenh. 1. c. 

 Polystichum Thelypteris, Both, Syn. Fl. Germ, et Helv. ed. ii. p. 917. Gren. & Godr. 



Fl. de Fr. Vol. III. p. 630. 

 Polypodium Thelypteris, Linn. Mant. PI. p. 505. Sm. Engl. Bot. No. 1018. 

 P. palustre, Salisb. Prod. 403. 

 Acrostichum Thelypteris, Linn. Sp. PI. 1528. 

 Thelypteris palustris, Schott, Gen. Fil. sub T. 10 in note. 

 Hemestheuni Thelypteris, Newm. Phyt. 1851. App. xxii. ; and Hist. Brit. Ferns, 



p. 124. 



Caudex very long, slender, wiry, creeping, much branched, the 

 youngest portion with a few ovate obtuse pale very deciduous 

 scales. Fronds of 2 kinds, produced at distant intervals along the 

 rhizome, either solitary, or (in luxuriant plants) a few together in 

 small fascicles, deciduous. Fertile fronds erect, with the stipes as 

 long as, or longer than, the lamina, slender, slightly channelled 

 in the upper part, containing 2 vascular bundles, pitchy-black 

 at the base, with a very few pale ovate-acuminate scales, which 

 soon fall off and leave the stipes naked. Lamina firm, yellowish- 

 green, almost without glands (at least when full grown), oblong 

 or strapshaped-oblong, abrupt at the base, rather abruptly acumi- 

 nated into an acute apex, pinnate ; pinna? all shortly stalked, 

 triangular-strapshaped, pectinate-pinnatifid or -pinnati partite ;' ulti- 

 mate segments convex, narrowly triangular-strapshaped or trian- 

 gular-oblong, more or less falcate, acute, entire, with recurved 

 margins. Ultimate veins running from the midrib to the margins of 

 the segments, forking near their base, those towards the apex of the 

 segment generally simple. Rachis not scaly, or rarely with a few 

 ovate brown scales. Sori attached to the back of the ultimate veins, 

 forming a line on each side of the mid-vein about half-way between 

 it and the margins of the segments, more or less covered by the 

 recurved margins, ultimately confluent all over the lower surface of 

 the segments. Indusium hyaline, soon disappearing, reniform, with 

 minute stalked glands round the margin. Spores muricated. Sterile 

 fronds produced earlier than the fertile ones, less erect, and not so 



