A Synopsis of the Genera Skyttea, Llimoniella and - Lichens of ...

462 THE LICHENOLOGIST Vol. 32
4(2) Ascomata, when mature, deeply cruciate; margin divided by 3 or 4
deep fissures, almost completely covering the disc, except when
old; ascospores 9-12(-13) x 3—4(—4-5) (im; on Lecidea fuscoatra
R. fuscoatrae
Ascomatal margin, when old, not deeply fissured; ascospores
7-10 x 3-4 um; on Porpidia R. makarovae
5(1) Ascomatal margin with hairs (Figs 1A, 14 p. p.) (in R. cruciatus only
visible in microscopical section) 6
Ascomatal margin without hairs (Fig. 14p.p.) 8
6(5) Ascospores narrowly ellipsoid to fusiform, 10-15 x 2-3-5 (im;
ascomata with or without hairs; on Pertusaria panyrga (Fig. 14)
R. pertusariae
Ascospores ellipsoid, mostly under 9 urn 7
7(6) Exciple entirely covered by hairs; ascomatal margin usually without,
or with inconspicuous fissures; ascospores 5-5-9 x 2-5-3-2 um;
green pigment present in the epihymenium and the upper exciple;
on Lepraria lobificans and Lepraria sp R. pubescens
Hairs restricted to the excipular margin; ascomatal margin often
divided by a few deep fissures; ascospores 7-8-5(-10-5) x (2-5-) 3-
3-5 jxm; green pigment only present in the epihymenium, exciple
entirely brown; on Diploicia canescens R. cruciatus
8(5) Ascospores 15-17(-20) x 2-5-3 um; on Stereocaulon
R. stereocaulorum
Ascospores shorter 9
9(8) Ascomata deeply cruciate; margin divided by 3 or 4 deep fissures,
almost completely covering the disc, except when old; ascospores
9-12 (-13) x 3-4 (-4-5) um; on Lecidea fuscoatra
R. fuscoatrae
Ascomata not cruciate, margin not, or not deeply fissured. ... 10
10(9) Ascospores 10-15 x 2-3-5 um (Fig. 14); on Pertusaria panyrga . . .
Ascospores shorter
R. pertusariae
11
11(10) Ascomata partly immersed when young, soon superficial; ascospores
(8-)9-ll(-14) x 2-3(-3-5) urn; asci 35-45 x 6-5-8 um; on the
Lepraria neglecta-group R. neglectus
Ascomata immersed, almost perithecioid when young (Fig. 13),
later erumpent to superficial; ascospores 7-10 x 3-4 um; asci
47-57 x 6-8 um; on Porpidia R. makarovae
Rhymbocarpus boomii Etayo & Diederich sp. nov.
A Rhymbocarpo geographici ascosporis parvioribus, 8-10.5 x 3-4 pm differt.
Typus: Spain, Mallorca, between Cala D'Or and Porto Colom, Cala Arsenau (Cala Sanau)
coastal area, 20 m, on Juniperus phoenicea, mixed with Pinus halepensis, Pistacia and Oka, on Dirina
ceratoniae, 3 April 1997, van den Boom 18478 (MA-Lich—holotypus; hb. Etayo—isotypus).