Bulletin of the British Museum (Natural History)

LICHEN GENUS MICAREA IN EUROPE 105
32a (31b) Apothecia pale reddish or orange-brown, small, 0-15-0-35 mm diam, sometimes
tuberculate and up to 0-6 mm diam, but never forming large nodulose clusters.
Spores ovoid-fusiform, often slightly curved, (0-)l(-3)-septate, 9-16x2-5-4-5 /xm. Pale
reddish brown, stalked pycnidia often present. Thallus usually poorly developed, never
waxy 3. M. anterior (p. 112)
32b Apothecia pallid, at first ± plane and adnate, 0-2-0-4(-0-6) mm diam, later often coalescing to
form large nodulose clusters up to 2 mm wide. Spores ellipsoid, ovoid or oblong, never
curved, (0-)l -septate, 9-16x3-5 ixm. Without stalked pycnidia, but white, convex sporodochia
(0-1-0-25 mm diam) usually present, bearing simple, ellipsoid macroconidia,
6-10x2-3 /um l.M. adnata (p. 108)
33a (30b) Thallus and apothecia sections C-l- red (? gyrophoric acid). Epithecium fuscous-brown.
Hypothecium pale. Spores markedly curved, 1-septate , 9-12 x 2-5^ fim . On rock
10. M. curvata (p. 126)
33b Thallus and apothecia sections C—; without remaining combination of characters 34
34a (33b) Upper hymenium with well defined fuscous-brown epithecium, pigment unchanged in
colour but dissolving into solutions in K. Hypothecium hyaline to dilute yellowish brown.
Phycobiont micareoid. Mostly on lignum or old bark 35
34b Upper hymenium otherwise; if fuscous-brown then pigment not dissolving in K and plant not
on bark or lignum. Hypothecium hyaline, pale or dark. Phycobiont micareoid or not.
Substrata various 36
35a (34a) Spores 0-l(-3)-septate, (9-)ll-15(-19)x 2-3-5 /am. Thallus of dispersed to contiguous,
whitish, grey-brown or olivaceous-brown, convex to ± globose areolae. On lignum or old
bark, very rarely on rock 12. M. elachista . (p 131
35b Spores 0(-l)-septate, 6-9-5 x 1 -5-2-3 /xm. Thallus endoxyUc. On lignum
36. M. rhabdogena (p. 181)
36a (34b) Hypothecium hyaHne, yellowish, dilute orange-brown or dilute greenish, not blackish
in thick sections 37
36b Hypothecium dark throughout, often blackish in thick section 42
37a (36a) Apothecia dark brown or black. Spores 0-1-septate, c. 9-14x4—6 ± m. On exposed
rocks 38
37b Apothecia pale; if dark then spores simple and/or smaller. In sheltered situations on shaded
rocks, exposed tree-roots etc 39
38a (37a) Upper hymenium brown. Phycobiont micareoid. Pycnidia usually present, with either
helicoid macroconidia or cylindrical microconidia 39. M. subnigrata (p. 183)
38b Upper hymenium green. Phycobiont not micareoid, thick-walled, 7-21 /xm diam. Pycnidia
unknown 17. M. intrusa (p. 138)
39a (37b) Spores small, in range, 4-8-5x1-2-5 /xm, single or 1-septate. Apothecia small, mostly
less than 0-3 mm diam 40
39b Spores larger, c. 7-10x3^-5 fim, simple. Apothecia usually larger, often more than 0-3 mm
diam 41
40a (39a) Spores mostly 1-septate, 6-8-5x1-5-2-5 /xm. Apothecia orange-brown or reddish
brown . Hypothecium
dilute orange-brown . Phycobiont (?) micareoid , cells 4-7 /am
28. M. myriocarpa (p. 161)
40b Spores simple, 3-6x1-2 /am. Apothecia blue-grey to blackish. Hypothecium dilute green.
Phycobiont cells 5-12(-18)x 3-8 /am, often in pairs or short chains Psilolechia clavuiifera (p. 201)
41a (39b) Phycobiont not micareoid, cells 5-12 /am diam. Apothecia pallid to black. Upper
hymenium hyaline to dark green or aeruginose. Hypothecium hyaline, or dilute greenish in
upper parts 5. M. bauschiana (p. 117)
41b Phycobiont micareoid, cells 4-8 /am diam. Apothecia pallid, dull yellowish-orange to reddish
brown. Upper hymenium hyaline. Hypothecium straw-yellow to dilute orange-brown
20. M. lithinella (p. 147)
42a (36b) Hypothecium fuscous or ± reddish brown, without distinct purple or greenish tinges in
water or K, HNO3- or -I- bright orange-brown, never -I- purple-red 43
42b Hypothecium with distinct purple or greenish tinge in water and/or K, HN03-F purple-red 50
)