82 HËPATIOÆ.
8. Sub-braot x IG (Portugal, bb. S.O.L.). 9. Sub-bracteole x 16
(ditto). 10. Bract x 11 (ditto). 11. Bract and bracteole x 11
(ditto). 12. Perianth x 11 (ditto). 13. Portion of moutli of
perianth x 85 (ditto).
2. Porella Thuja {Dicks.), Aloore.
Lichemmlrmn arhm-is mice facie, foUis rotundioribus. Dill. Hist. nmsc. p. 502,
t. 72, f. 33 (1711).
Jungermania Thuja, Dicks. PI. Crypt. Brit. Fuse. 4, p. 19 (1801); I’ayl. in
Trans. Bot. Soc. Edin. xi. p. 116 (1841).
Madotheca Thuja, Durn. Comm. p. I l l (1822).
Porella Thuja (Dicks.), Moore in Proc. li. I . A. 2nd ser. vol. ii. p. 618 (1876).
Dioicous, imbrieately cæspitose, largish to large, brown or
olive-brown, apices of branches often pale yellow. Stem
irregularly bipinnate, frontally compressed, cross-section showing
about 100 cortical cells very small with tliick dark walls, 25 x 30
cells in diameter, inner cells large and hyaline; more or less
robust, firm ; radiculose, rootlets fasciculate,, coarse, reddish-
brown, produced from the base of the stipules. Leaves incubous,
appressed, involute when dry, closely imbricate, horizontal,
unequally bilobed, antioal lobe much larger, convex, obliquely
rotund-ovate, apex decurved, rotundate-obtuse, margin entire, or
rarely with few distant teeth; postical lobe or lobule hardly
deourrent, very slightly attached at its base to the antical lobe,
patent, ovate to ovate-oblong, apex obtuse or aonte, sometimes
uncinate, margin recurved, entire or rarely with few small teetli
near tlie base ; a little longer and narrower than the stipules ;
texture subopaque, firm but pellucid, epidermis slightly polished,
verruculose, cells smallish 4-, 5- and 6-angled, roundish-quadrate,
walls tliick, trigones distinct. Stipules imbricate, appressed to the
stem, deourrent, sub-reniform, sub-cordate or oval, broader than
long on stem, longer than broad on branches, margin reflexed,
entire or rarely with few teetli near the base. Female flowers on
short lateral branchlets, only imperfect ones seen. Bracts larger
than the leaves, antical lobe oblong-ovate or obliquely rotund-
ovate, apex subacute, margin irregularly dentate, postical lobe
about 3 times smaller tlian the antical, oblong or oblong-ovate,
apex obtuse or subaoute, margin irregularly dentate; bracteole
broadly ovate, irregularly dentate. Pistillidia numerous, 10-22
long and narrow. Male stems pinnate, with few short branches
androecia numerous on sliort lateral alternate catkins ; perigonial
bracts 6-8 pairs, closely imbricate, erect, bilobed, postical lobe
small and oblong ; antiieridia subspherioal to oval, solitary.
Dimensions.—Stem 2 to 3 inches long (var. forva 1 inch),
diameter ’4 to A mm., with leaves 2'25 mm. to 3' mm. wide ;
leaves, antical lobe 1'8 mm. x 1'8 mm., postical 1'2 mm. x A inm.,
antioal lA mm. x 1'2 mm., postical -85 mm. x A mm., antical
1'8 mm. X lA mm., postical 1' mm. x ’6 mm., antioal 2 ‘ mm. x
1 7 5 mm., postical 1'4 mm. x 7 5 mm., antical 1' mm. x ’8 ram.
postical -6 mm. x ’4 mm. ; cells '03 mm. x '02 mm., '025 mm. x
'025 mm., '025 mm. x '02 mrn.; stipules 1' mm. x 1. mm.,
I'S mm. X '9 mm., '7 mm. x '7 mm., '7 mm. x '8 mm., 1' mm. x
'8 mm. ; bract, antioal lobe 1'7 mm. x 1'2 mm., postical 1'35 mm.
X '6 mm., antical 2'25 mm. x 2 mm., postical 1'5 mm. x 1' mm. ;
bracteole 1'25 mm. x 1'25 mim, 1 '1 mm. x '8 mm. at base ; pistillidia
'4 mill. X '075 mm. ; perigonial bract, antical lobe T'5 mrn. x
1' mm., postical '8 mm. x '4 mm. ; perigonial bracteole '75 mm. x
'45 mm. ; antiieridia 4' mm. x '35 mm.
H ab.—On rocks, stones or trunks of trees. Rare.
1. Var. torva, Penzance, W. Curnow. 2. Var. torva, Sussex,
G. Davies. 7. Ravine above Barmoutli, Merioneth, Dr. Carrington.
Near Snowdon, Carnarvon, Dr. Carrington. 12.? 16.
Braemar, Dr. A. 0. Black. I. Cromaglown, Dr. Carrington. By
Lougli Mangerton, Holt and Stewart.
1 ound on the Continent (France, 'Montague. Oporto, Portugal,
Newton, $. Var. torva, Italy, de Notaris).
North America.
ObS' Remarkable for its somewhat robust habit, dark brown
to almost black colour, leaves being very closely imbricate, involute
when dry and slightly polished, and rounder than any other
of the Bi'itisli species.
Distinguished from P. platgphglla (L.) by its rounder leaves.