32
ciliaris
and
Pseudevernia furfuracea
) have a basically foliose, flattened thallus, which,
however, tends to develop into three dimensions, and is not attached to the substratum by
rhizines.
Foveolate
(of thallus): with small, shallow depressions.
Fruticose
(of thallus): developing in three dimensions, often shrub-like, and round to inflated in
section, gas exchange occurring throughout the surface. See also
foliose
, and
squamulose
.
Fusiform
(of spores): spindle-like, broader in the centre and narrowing towards the ends.
Gelatinous
(of thallus - cyanobacterial lichens): becoming jellyish when wet (e.g.
Collema
).
The cyanobacterial cells are surrounded by coats which tend to absorb liquid water,
becoming jelly-like when wet. This character is easy to appreciate in some genera (e.g.
Collema
) in which the photobiont is predominant, less easy in other genera, like
Leptogium
.
See also
homoiomerous
,
heteromerous
.
Glabrous
: without hairs.
Glaucescent
(of colours): bluish-greenish grey.
Globose
: spherical.
Gloeocapsa:
a genus of
cyanobacteria
characterised, together with several other similar genera,
by more or less spherical masses containing clusters of cells with a distinct, sometimes
pigmented gelatinous coat. Most frequent in the Lichinaceae.
Goniocyst:
more or less spherical groups of green algal cells surrounded by short hyphae, but
without a true cortex (section!), forming a minutely-granulose thallus (e.g. in
Micarea
).
Granules
(of thallus parts): thallus consisting of small, coarse, more or less spherical elements.
Granulose
(of soredia): coarse, looking like
granules
. See also
farinose
.
Hairs
: short, erect, transparent, hair-like structures, generally present on the upper cortex, and
formed by a single
hypha
(e.g. in
Agonimia opuntiella
,
Phaeophyscia hirsuta
). See also
cilia
,
fibrillae
, and
tomentum
.
Halonate
(of spores): with a thick, transparent, gelatinous outer coat. See also
perispore
.
Hamathecium
(of ascocarps): a rather difficult, “neutral” term, which is never used in our keys,
referring to all types of sterile
hyphae
(
paraphyses
,
paraphysoids
,
periphyses
, etc.) which
occur in the
hymenium
.
Haustorium
(plural: haustoria):
hyphae
of the
mycobiont
which penetrate inside the cells of the
phycobionts
.
Hemi-
(general suffix): almost, partially.
Hemiangiocarp
(of ascocarps): the
hymenium
is initially protected by a covering layer, which
disrupts when the
asci
are ripe. Not used our keys. See also
angiocarp
.
Hemiendolithic
(of thallus): see
hemiendosubtratic
.
Hemiendosubstratic
(of thallus)
:
embedded in the substratum, except the photobiont layer (e.g.
Caloplaca ochracea
as opposed to
Bagliettoa
-species). This character may be difficult to
appreciate, and is used very rarely in our keys.
Heterocyst
(of photobionts): a cell of filamentous
cyanobacteria
which differs from the others
in the chain by its paler inner side and its thicker wall, devoted to nitrogen fixation. This
term is never used in our keys.
Heteromerous
(of thallus): having the
mycobiont
and the
photobiont
separated into well-
distinct layers, usually
dorsiventral
. See also
homeomerous
,
gelatinous when wet
.
Homeomerous
(better:
homoiomerous
, of thallus): having the
mycobiont
and the
photobiont
evenly intermixed throughout the
thallus
(e.g. in
Collema
). See also
gelatinous when wet
,
heteromerous
.
Hyaline
(of spores): transparent, colourless.
Hymenial algae
(of lichens with
perithecia
): green algal cells contained inside the
hymenium
of some groups of
pyrenocarpous
lichens (e.g.
Endocarpon
,
Staurothele
). They are often
visible under a binocular, the sections of
perithecia
having a bright green core. These algae
are often different in shape and size from those of the thallus.
