so-oallod indusium, whioli is either not constantly produced or is
sometimes not easily found. This inner membrane lies next the surface
of tho frond beneath tho spore oases, which latter are covered
by tho evident roflexed indusiform margin. We believe when better
understood this will ho found to indicate a structure quite analogous
to that of the Lindsiem, the sporo-casos lying in a continuous line,
between an inner and an outer indusium, tho latter of which is
formed from the attenuated margin; differing ixom Lindscem in little
beyond the fact of tho sori being deflected so as to come in contact
with tho under surface of the frond. If this should prove to he tho
case, it is evident that this group of Pteris must be separated from
the other larger group in which no inner indusium is found. It
would in this case be most convenient as involving the fewest
changes in nomenclature to distinguish tho Ornitliopteris or smaller
group by some other name, leaving tho Eupteris or larger group
under tho present name of Pteris. There is good reason to conclude
that the structure which occurs in this case is the same as
that of tho long doubtful gonus Pissia of St. Hilaire, and if it
becomes necessary to carry out the separation already hinted at,
Pcesia has the strongest claim to receive the species requiring to be
removed. For tho present, however, our British plant may bo left
in the position it has occupied since the time of Linnaius.
There are various netted-veined species having pteroid fruotification,
which have been removed to other genera, by far the larger
proportion of these heing included in LitohrocMa. Even when thus
reduced to tho free-veined species having the pteroid fructification,
Pteris forms an extensivo and widely dispersed family.
Tho name is the Greek pteris, which was applied to some kind of
fern; it is derived from pteron, a wing or feather, and was no doubt
used in allusion to the plumy or feathery character of the plants to
which it was originally applied.
BRITISH SPECIES.
p . aquilma i a perennial, with ta ll M-tri-pimiato fronds, from a subterraneous
creeping caudex.
THE COMMON BRAKES, or BRACKEN.
PTERIS AQUILINA.
P. fronds large, coriaceous, bi-tri-pinnate, pubescent beneatb ;
primary pinnæ sub-opposite, in pairs ; ultimate divisions (pinnulets)
sessile, entire or pinnatifid, the terminal one often longer ; indusium
double, ciliated, the inner one sometimes obsolete ; caudex creeping,
subterraneous. [Plate XGYIII.]
P t e r i s a q u il in a , Linnoeus, Sp. Plant. 1533. Bolton, Fil. Brit. 16, t. 10, (Lad).
Smith, Eng. Bot. xxiv. t. 1679 ; Id ., Eng. FI. 2 ed. iv. 305. Hooker ds
Arnott, B rit. FI. 7 ed. 590. Mackay, FI. Hih. 343. Bahington, Man. Brit.
Bot. 4 ed. 427. Deakin, Florigr. B rit. iv. 54, fig. 1588. Newman, Hist.
Brit. Ferrts, 2 ed. 93. Moore, Handh. Brit. Ferns, 3 ed. 223 ; Id ., Ferns o f
Gt. BrU. Natiore Printed, t. 44. Sowerhy, Perns o f Gt. Brit. 67, t. 38.
Bentham, Ilandh. B r it. FI. 635. Hooker, Sp. Fil. ii. 196 (excl. 5.) ; iii. t.
141 A (indusium). Swartz, Syn. Fil. 100. Schkuhr, Krypt. Gew. 87, tt. 95,
96. Willdenow, Sp. Plant, v. 402. Sprengel, Syst. Veg. iv. 78. Koch, Syn.
2 ed. 984. Fries, Sum. Veg. 830. Ledebour, FI. Ross. iv. 524. Sturm, FI.
(F a rm .) t. 9. Svensk Bot. t. 90. Flora Dan. t. 2303. Agardh, Recens.
Sp. Pter. 49. Fée, Gen. Fil. 126, t. 11 A, fig. 3 (stipes). Mettenius, Fil.
H o r t B o t Lips. 59 ; Id ., Pter. t. 16 fig. 13-15. Lowe, N a t H is t Ferns,
iv. t. 3. Nyma n , Sijll. FI. Eur. 433.
P t e r i s b o r e a l is , Salisbury, Prod. 402.
P t e r i s foe m in a , Gray, N a t A rr. B r i t PI. ii. 16.
P t e r i s c a u d a t a , L in k , Enum. P la n t a l t ii. 464 (excl. s y n . ) ; according to
Link.
P t e r i s b r e v i p e s , Tauseh, Flora, (Regens. Bot. Zcit.) xix. 427 ; Id ., xx. 351.
P t e r i s n u d ic a u l is , Gilldenstadt, Itin . i. 421 ; according to Ledebour.
P t e r i s r e c u r v a t a , Wallich, Cat. 113. Agardh, Recens. Sp. Pter. 50.
P t e r i s e x c e l s a , Blume, Enum. P la n t Lav. 213,
P t e r i s f i r m a , Wallich, C a t 100.
P t e r i s t e r m in a l i s , Wallich, Cat 101.
P t e r i s W ig h t ia n a , Wallich, Ca t 2178.
P t e r i s l a n u g in o s a , Bory MS. Willdenow, Sp. P la n t v. 403. Sprengel, S y s t
Veg. iv. 78. Kaulfuss, Enum. Fil. 189. L in k , Envm. P la n t a l t ii, 464.
Agardh, Recens, Sp. Pter. 51 (incl. j8.), Fêe, Gen. Fil. 126.
P t e r i s d e n s a , Wallich, Ca t 99.
P t e r i s d e c o m p o s i t .4, Gaudichaud, Frey. Voy. 393 ; according to Hooker.
P t e r i s r e v o l u t a , Blume, Enum. Fil. Jav. 214. Agardh, Recens. Sp. Pter. 53.
P t e r i s v il l o s a , Fée, Gen. Fil. 126, 128 (excl. tb e reference to Cuming 408,
wbich is Cheilanthes tenuifolia).
P t e r i s c a p e n s is , Thunherg, Prod. 172. Willdenow, Sp. P la n t v. 393. Schlech-
tendal, Adumb. P la n t 45, t. 26. Agardh, Recens. Sp. Pter. 51,
A l l o so r u s a q u il in u s , Presl, T en t Pterid. 153. Pappe Rawson, Syn. Fil.
A fr . Aust. 32.
A l l o so r u s t a u r ic u s , Presl, T en t Pterid. 154, according to Ledebour.
A l l o so r u s e e c u r y a t u s , Presl, Tent. Pterid. 154.
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