Bulletin of the British Museum (Natural History)

122 BRIAN JOHN COPPINS
Breslau: 233 (1853). - Bilimbia delicatula (Korber) Korber, Syst. lich. Germ: 212 (1855). Type: lectotype
as for Lecidea sphaeroides var. albella Schaerer. See note (ii) below.
Bilimbia cinerea f. hypoleuca Stizenb. ex Arnold in Flora, Jena 58: 598 (1864). - Micarea cinerea f.
hypoleuca (Stizenb. ex Arnold) Hedl. in Bih. K. svenska VetenskAkad. Handl. Ill, 18 (3): 82, 93 (1892).
Type: Germany, Bayern, near Eichstatt, Affenthale, on young Picea abies in a wood, viii 1864, F. C. G.
Arnold (M - lectotype!).
Notes, (i) No material labelled Lecidea sphaeroides var. albella could be traced in G (Geissler, in litt.)
and an undated specimen in M is selected as neotype. If it can be proven that this specimen was collected
before 1833, it should be regarded as a lectotype.
(ii) No material referred to in the protologue of B. delicatula has been traced in L, WRSL or elsewhere.
However, Korber gives 'Lecidea sphaeroides a albella Schaer. Enum. 193.' as a synonym. This citation
refers to Schaerer (1850) and is an indirect reference to Lecidea sphaeroides var. albella Schaerer (1833).
Consequently I have typified both names with the same specimen in M.
Thallus effuse, sometimes partly immersed in the substratum (especially when on lignum),
more usually developed on the surface of the substratum as rounded, shallow-convex, hemispherical
or ± globose areolae. Areolae scattered to ± contiguous, smooth, greenish white to
blue-grey, or more rarely becoming dark grey, often dark coloured on upper surface but
greenish white below, c. 40-160 fxva diam or up to 300 jxm diam if containing a pycnidium of the
macroconidial anamorph. Areolae in section, ecorticate but with a hyaline amorphous covering
layer c. 2-5 /xm thick; outermost hyphae often with grey-green to aeruginose walls, K-,
HNO3-I- red. Phycobiont micareoid, cells 4-7 /xm diam.
Apothecia usually numerous (see 'observations'), adnate, plane to convex, sometimes
becoming tuberculate, sometimes with an indistinct margin that is ± flush with the level of the
disc, pale leaden-grey to grey-black (margin often paler), or ivory-white or pallid in shade forms,
(0-2)0-3-0-7 mm diam or up to 1-3 mm when tuberculate. Disc matt and finely roughened, but
margin smooth and often ± glossy. Hymenium 55-70 /xm tall, hyaline, but usually olivaceous or
aeruginose (K— , HNO3+ red) in upper part (epithecium). Asci clavate 50-65x15-20 /am.
Spores fusiform, often slightly curved, (3-)5-7-septate, (19-)23-34(-38)x 4-5-6 ixm. Paraphyses
numerous, branched and often anastomosing, 1-1-4 /xm wide; apices often more richly
branched and entangled, often slightly incrassate to c. 1-8 ^im, or 2-5 /xm due to thickening by
greenish pigment. Hypothecium c. 40-70 /xm tall, hyaline; hyphae interwoven, c. 2-4 /xm wide.
Excipulum well developed, hyaline or pale straw, or richly branched and anastomosing hyphae,
c. 1-1-5 /xm.
Pycnidia frequently present, of two types: (a) immersed in areolae, white or faintly greenish
around the ostiole, 160-300 /xm diam, ostiole often widely gaping; conidia (macroconidia) ±
straight or flexuose, filiform, 9-17-septate, 50-1 10 xc. 1 /xm; (b) ± sessile, white, c. 40-70 /xm
diam, ostioles not, or only slightly, gaping; conidia (microconidia) narrowly fusiform-cylindrical
(3-8-)^5xO-5-0-7/xm.
Chemistry: Thallus and whitish apothecia K-, C-l- red, PD-; apothecia in section C-l- red;
t.l.c: gyrophoric acid.
Observations: M. cinerea is very variable with regard to the colour of its apothecia and thallus;
as with M. peliocarpa this variation is due to the amount of green pigment produced in response
to environmental factors, especially light. Morphologically and chemically M. cinerea is closely
allied to M. alabastrites and M. peliocarpa; the diagnostic features of each of these three species
are compared in Table 4. Forms of M. cinerea with blackish apothecia can be confused with M.
lignaria (including var. endoleuca) but on close inspection the latter will be seen to differ in its ±
globose apothecium with a poorly differentiated excipulum (in vertical section), usually
brownish or greenish upper hypothecium, less strongly branched paraphyses and chemistry.
M. cinerea is usually well fertile with numerous apothecia, but sterile forms with numerous
macroconidia-containing pycnidia have been encountered; the macroconidia are about twice as
long as those found in M. peliocarpa and M. alabastrites and so are readily identifiable (see 'Key
to species without apothecia, pp. 107-108).