The English flora - SeaweedAfrica

134
LICHENES.
dered, entirely formed of the substance of the thallus, the disk
sometimes coloured.
/3. Apothecia uniform, not, or scarcely, margined, suborbicular, often
having the appearance of the nail of the human hand (peltce).
Fam. XI. PeltigerejE.
21. Solorina. Thallus foliaceous, coriaceous, lobed, free, beneath
having fibrous or woolly veins. Apothecia ( peltce) adnate,
sometimes immersed, orbicular (distant from the margin), not
bordered.
22. Peltidea. Thallus foliaceous, coriaceous or membranaceous,
spreading, lobed, with woolly veins beneath, the lobules
fertile. Apothecia ( peltce) suborbicular, adnate on the tipper
side of the lobules or proper portions of the thallus and having
a border formed of the thallus.
23. Nephroma. Thallus foliaceous, coriaceous or membran-
aceous, spreading, lobed, naked or hairy beneath, the lobules
fertile. Apothecia (peltce) orbicular, reniform, adnate on the
underside of the lobules or proper portions of the thallus and
having a border formed of the thallus.
b. Attachment of the, more or less orbicular, thallus by the centre.
Fam. XII. Umbilicarie^s.
24. Gvrophora. Thallus foliaceous, coriaceous or membranaceous,
fixed by the centre, peltate. Apothecia (trices or gyromata)
orbicular, subscutelliform, sessile and adnate, covered by a black
membrane, the disk marked with concentric circles or plicce with
a border of its own substance.
25. Umbilicaria. Thallus foliaceous, coriaceo-membran-
aceous, pustuled, fixed by the centre, peltate. Apothecia orbicular,
somewhat concave, adnate, covered by a black membrane,
the disk at length tubercled, with a border of its own
substance.
B. Upper and under surfaces of the thallus alike.
a. Thallus usually compressed and laciniated. Apothecia scutel-
liform (scutellce).
Fam. XIII. Ramaline^:.
26. Cetraria. Thallus foliaceous, cartilagineo-membraua-
ceous, ascending or spreading, lobed and laciniated, on each side
smooth and naked. Apothecia orbicular, obliquely adnate with
the margin of the thallus, the lower portion being free (not
united with the thallus); the disk coloured, plano-concave, with
a border formed of the thallus and inflexed.