192 ENGLISH BOTANY. 
siclcrs exactly Fries' s plant ; but Pries distinctly says, " Involucre 
sub-nuda, nigra-glandulosa pilosa," which does not apply to the 
Knaresborough plant. 
The variety 7, Mr. Baker considers an intermediate form between 
II. murorum and H. caesium, agreeing with the former in habit and 
in the size and shape of the heads : with the latter in the mature 
leaves becoming glaucous and sub-coriaceous, and the stem-leaf 
being much reduced and sessile. 
A plant from the foot of Glen Esk, collected by Mr. Croall, 
which Mr. Backhouse refers to II. murorum, has the heads sub- 
umbellate, the stem and leaves densely woolly, and the pericline 
sub-globular after flowering. I should have referred it rather to 
II. caesium. 
Wall Hawkweed. 
French, Eperviere des Murs. German, Mauer HabicJdsJcraut. 
SPECIES XXIV— H IERACIUM CESIUM. Fries (?). 
Plate DCCCXLVII. 
Reich. Ic. EL Germ, et Helv. Vol. XIX. Tab. MDXXIV. Fig. 2. 
Back. Mon. Hier. p. 56. Bab. Man. Brit. Bot. ed. v. p. 205. Hook. & Am. Brit. FL 
ed. viii. p. 227. Fries, Epic. p. 92 (?). 
" If. murorum, var. a, Linn. Sp. Plant, p. 1128." Fries. 
II. murorum, JSm. Eng. Bot. No. 2082. 
Stem scape-like, corymboscly branched at the apex, sub- 
glabrous below, above and on the peduncles, rather densely 
clothed with stellate down intermixed with a few simple black- 
based hairs, and sometimes a very few gland-tipped hairs. Radical 
leaves sub-coriaceous, oblong-oval or oval, or oblong-lanceolate, 
more or less abruptly attenuated into short woolly petioles, sub- 
obi use or acute, remotely denticulate or dentate, especially 
towards the base where the teeth are often large, with soft hairs 
on both sides or only beneath, without stellate down ; stem 
leafless or with a single leaf, which is usually above the middle 
of the stem, very small, sessile, and bract-like. Anthodes rather 
large, 3 to 7, in a lax corymb, with the peduncles elongate, 
ascending, usually nearly straight. Pericline hemispherical at 
the base, ovate-ovoid after flowering ; phyllaries numerous, acute, 
the outer ones sub-obtuse, dark-olive, densely clothed (especially 
towards the margins) with stellate down intermixed with more or 
less numerous white or white-tipped hairs, but with very few or 
no black gland-tipped hairs. Florets sub-glabrous, not ciliated. 
Styles livid-yellow. Plant glaucous. 
