Plate 38 . 
PTERIS (§ Ornithopteris) aquilina, Linn. 
Common Brake or Bracken. 
Gen . Char. Sori continuous, linear, marginal. Involucre formed of the 
reflexed margin of the frond, and frequently dilated into a membrane 
(sometimes double, as in Ft. aquilina). —Fertile fronds unchanged , except 
in the segments being more contracted: veins forked, free, in the only British 
species. 
Pteris (§ Ornithopteris) aquilina; caudex running long and deep underground ; 
stipites erect, remote, tawny; fronds ample, subdeltoid, coriaceous, tripin- 
nate, glabrous or hairy beneath; primary divisions long-petioled ; ultimate 
pinnse sessile ; pinnules spreading, linear, more or less approximate, entire 
or hastate, or deeply pinnatifid ; segments oblong or linear, ultimate ones 
more or less elongated ; involucre double, membranaceous, more or less 
villous and ciliated (inner one the smaller, sometimes obsolete). 
Pteris aquilina. Linn. Sp. Pl.p. 1533. Sw. Sgn. Fil.p. 100. Willd. Sp. PI. 
v. 5. p. 402. Ag. Sp. Gen. Pterid.p. 49. Sm. Engl. Bot. t. 1679. Engl. 
El. v. 4. p. 318. Hook, and Am. Brit. FI. ed. 8 .p. 592. Hook. Sp. Fit. 
v. 2. p. 196. t. 141 A and B ( and see copious remarks on this species in note 
p. 195). Moore , Brit. Ferns , Nat. Print, t. 44. 
Allosorus aquilinus. Pr. Tent. Pterid.p. 153. 
Pteris caudata. Schkh. Fit. t. 95, 96. Hook, and Am. Pot. of Beech. Voy. 
p. 455 (i not Linn). 
Pteris recurvata. Wall. Cat. n. 113, and Pt. firma, ejusd. n. 100. 
Hub. The most commo'n of all Ferns in open heaths, woods, and thickets, and 
upon elevated mountains throughout England, Scotland, and Ireland: in 
open situations seldom attaining a large size; but in favourable spots, far 
exceeding the height of a man, and forming a favourite haunt of deer. 
The commonness of this plant renders it less an object of 
interest than its merits deserve. It was called aquilina by 
Linnaeus, from a fancied resemblance to the imperial eagle* on a 
transverse section of the base of the stipes. This appearance is 
due to the vascular bundles of tissue being arranged in a pecu¬ 
liar, sinuose manner, around the central cellular substance, which 
is of a different colour from the rest of the interior, and indeed 
* In England it is considered to bear a faithful resemblance to King Charles 
in the Oak. 
