CRAPHIS ScnIPTA - Universitetet i Oslo

Contributions to the knowledge of the lichen llora of the Himalayas
IX. Sagema, a new lichen genus (Lecanorales, Lecanoraceae)
MARTIN GRUBE and JOSEF POELT
Grube, M. & Poelt, J. 1993: Contributions to the knowledge of the lichen
flora of the Himalayas IX. Sagema, a new lichen genus (kcanorales, Ircanoraceae).
Graphis Scipta 5: 69-72. Stockholm. ISSN W0L-7593.
Sagema potentillae gen. et spec. nov. from the Central Himalayas is described
and illustrated. Superficially, it resembles some species of the Lecanora subfusca
group but is different in the structures of the asci, the anatomy of cortex
of the ascocarps, and in the thichvalled spores. At least for the time being
Sagema is positioned in the I-ecanoraceae.
Martin Grube and losef Poelt, Institut fur Botanilq Holteigasse 6, A-8010
Graz, Austia.
In the concept of hhlbruckner (e.9. 1926 p.
22L) the genus Lecanora was extremely large
and heterogeneous. In the last decades the
number of. Lecanora species was of course
reduced by the exclusion of remote groups, e.g.
Aspicilia, Eiglera, Orceolina, Placopsis, Trapelia
etc. On the other hand several taxa - some
of them formerly placed in Lecidea were
combined into Lecanora dve to principal concordance
concerning ascus characteristics.
Nevertheless the genus is rather inhomogeneous
even today. It would be desirable to
split the whole complex into smaller and
clearly delimited genera. But as long as the
diagnostic value of the characters is unclear,
any splitting is a gambling with the chance of
long instability.
The genus described below at the
moment represented by a single species is
based on a lichen which would obviously be
placed in the genus Lecanora in hhlbruckner's
scheme. However, it is well distinguished
by a number of characters and the description
of a new genus is legitimate and not too rashy.
Sagema potentillae* Poelt & Grube,
gen, et sp. nov.
Thallus crustaceus, subindistinctus. Apothecia
sessilia basi distincte angustata, lecanoroidea,
discis rubrofuscis, interdum verruculosis, et
marginibus distinctis subalbidis, vix elevatis,
demum reclusis. Amphithecium corticatuffi,
cortice hyphis anticlinalibus valde conglutinatis
constructo. Hypothecium paratheciumque
incoloratum. Hymenium incoloratum paraphysibus
anastomosantibus conglutinatis, vix
capitatis. Asci unitunicati-rostrati, tholo basin
versus valde producto. Sporae octonae ellipsoideae,
maiores, pariete percrasso, stratis
compluribus constructo. Continet acidum isousnicum.
Type: Nepal, Central Himalaya, Langtang
Area, Dupka, 4000 m, on Potentilla arbuscula,
* The name of the genus is an acronym of
Sabine and Georg Mrehe, the collectors of the
new lichen. The epitheton refers to the host
plant.