The English flora - SeaweedAfrica

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152 LICHENES. [Verrucaria.
it growing. Yet the structure of the crust seems very different, as well
as the colour both of that part and the fructification."—The tubercles
are much more minute than those of any other British Verrucaria.
13. V. leucocephala, Ach, (white-fruited Bark Verrucaria^);
crust between filmy and tartareous grey pruinose, apotliecia
largish prominent spherical or almost cylindrical brown covered
with white powder their apex at length bare. Borr.—Ach.
Meth.p. 116. Borr. in E. Bot. Stippl. t. 2642./. 2 Pyrenula
leucocepliala, Ach. Syn. p. 126.— Cyphelium leucocephalum, "Ach.
Sphccria leucocepliala,
Ehrh. and Pers.— S. lichenoides, Sow. Br. Fungi, t. 373.
in Stockl. Trans, for 1817, p. 226. t.S.f. 7."
f. 12. 3. amphibola ; apotliecia larger clustered often irregular.
Ach. Syn.
On the trunks of old trees, near the ground.— Among the tubercles,
as they appear to Mr. Borrer, of this plant, Mr. Lyell and Mr. Robertson
find patellulce of a dull purplish-black, covered with an inseparable super-
ficial buff powder. The same patellulce occur on sandstone rocks in
Sussex, intermixed with what may possibly be abortive tubercles of the
Verrucaria. These are figured on the plate in E. Bot. t. 2642./. 2. c,
and look externally very much like the fructifications of a Lecanora.
But whilst Mr. Borrer knows of no other Lichen to which these patellulce
can be referred, he yet believes that they do not belong to our
Verrucaria.
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** Growing on rock or stone. Saxicola?.
14. V. rupestris, Schrad. (immersed Bock Verrucaria); crust
indeterminate very thin whitish smooth, apotliecia small black
globose umbilicate sunk in a hollow of the crust and of the
stone. Schrad. Spicil. p. 109. t. 2./ 7.— V. Schraderi, Ach.
Syn. p. 93 Lichen Schrad.—E. Bot. t. 1711. Schair. Lich.
Helv. p. 55.71. 103, 104.— Verrucaria immersa, Hoffm. PI. Lich.
t. 12./ 2—4 ?
On chalk and calcareous stone, in which the apotliecia form cavities
often larger than themselves.— Mr. Borrer suggests that the V. immersa
of Hoffm. should be distinguished from this, and he observes that both
appear to have grown intermixed, as they frequently do on chalk, in the
specimen figured as Lichen Schraderi in E. Bot. But 1 am not aware of
the essential differences between them.
15. V. conchma, Borr. (neat Bock Verrucaria); crust determinate
very thin tartareous continuous even grey somewhat
pruinose, apotliecia of a middle size prominent hemispherical
umbilicate black. Borr. in E. Bot. Suppl. t. 2623./ 1.
Durham, Mr. Robson. Limestone rocks on the Durham shore of the
Tees, near Eglestone ; and on chalk on the Sussex Downs, Mr. Borrer.
Killarney, Sir T. Gage.— This differs from the V. rupestris by its limited
and even crust and its more prominent and larger tubercles.
1 6. V. ekeina, Borr. (olive-green Rock Verrucaria) ; crust
thin tartareous cracked smooth slightly tumid above the tubercles
greenish-olive, apotliecia small immersed black between
hem i sphserical and conical at length emerging. Borr. in E.