A NEW SPECIES OF FUSCIDEA (LICHENES) FROM THE CAPE FOLD MOUNTAINS

Thallus crustosus, saxicola, violaceo-brunneus, ad 80 mm diametro, 100300 /xm crassus, rimosovel dissitiareolatus. Areolae 0 ,2 -2 ,0 mm diametro. Hypothallus ater, thallum marginans, margine 0 ,5 -2 ,0 mm lato. Cortex superior circa 20 /xm crassus. Stratum gonidiale 20—100 fim crassum; algae Protococcoideae, 5—16 fim diametro. Medulla alba, 50— 200 fim crassa. Apothecia nigella, adnata, lecideina, ad 1,2 mm diametro, marginibus leviter brunneis vel atris, discis atris, planis vel concavis. Excipulum pallide brunneum, 35—45 /xm cras­ sum, anticlinate paraplectenchymatum, cellulis 4 —6,5 fim latis, 4 -1 5 ,5 fim longis. Hypothecium hyalinum, 6 5 -9 5 fim crassum. Hymenium hyalinum, 65 -7 5 /xm altum, solum ascis J+ caeruleis; epihymenium brun­ neum. Asci clavati, tholis J+ caeruleis. Ascosporae octonae, hyalinae sed mox fuscae, curvae vel reniformes, simplices vel interdum uniseptatae, 11,5—17,5 x 5 8 fim . Pycnidia hyalina, ampulliformia, circa 80 /xm lata et circa 100 /xm profunda. Pycnidiosporae* hya­ linae, rectae, anguste ellipsoideae, acrogenae, 3 -5 x 1 -1 ,4 /xm. Thallus acidum ramalinolicum continens.

However, the most conspicuous difference between these two species is the chemistry, with F. cyathoides containing fumarprotocetraric and protocetraric acids (James, Poelt & Wirth 1981;Oberhollenzer & Wirth, 1984), and F. hottentotta containing ramalinolic acid, with a minor amount of sekikaic acid.This was deter mined by thin-layer chromatographic comparisons of the hydrolysis products with those of divaricatic and homosekikaic acids, and the hydrolysis data presented by Culberson (1972).A negative homofluorescein test (Asahina & Shibata 1954) and microcrystal tests con firmed this determination.
Thus far this new species has verifiable specimen records from Robinson's Pass, at the western end of the Outeniqua Mountains and from Caledon, and is therefore widespread in the southern Cape Province.or acuminate-clavate, tholus J+ blue (Figure 13).Asco spores numerous (± 100 or more), simple, hyaline, ellipsoid, small, 5 -9 x 3,2-5,2 /xm.Pycnidia not seen.Chemistry: divaricatic acid only.
This is a unique new species of Maronea, because the apothecia are lecideine and the thallus is saxicolous, whereas all other species of Maronea known up to now have lecanorine apothecia and are corticolous.The lecanorine condition is characterized by a very reduced proper exciple and a well developed thalline exciple, not always in a protruded state.Oberhollenzer & Wirth (1984) treated several types of exciples in a single octosporous genus, Fuscidea V. Wirth & Vëzda.The spe cies with sunken apothecia and reduced exciples could be considered to have lecanorine apothecia, e.g.Fusci dea atlantica (Magn.)James & Poelt, originally de scribed as a Lecanora.In a similar vein, Hertel (1984) has treated several lichens with Lecanora-type ascus apices, and curved acrogenous pycnidiospores with leci deine exciples, as species of Lecanora rather than of Lecideay as would have been done in the past.The crea' tion of a new genus for this lichen, therefore, seemed unwarranted.
Under the old system of classification of lichens, this species would key out at Sarcogyne Fw. (Magnusson 1935;Poelt 1969;Zahlbruckner 1926), but this genus often has a poorly developed thallus (mostly cryptothalline), and the exciple is of a different structure and is dark brown to carbonized in colour.The paraphyses in Sarcogyne are ecapitate and strongly gelled, unlike the loose capitate paraphyses of Maronea afroalpina, and M. constans (Nyl.)Hepp, the type of Maronea (Hafellner 1984).
The major difference, the one which places Sarcogyne and Maronea in two different families, is the ascus apex, which is amply illustrated in Figure 2 and by Hafellner (1984) for Maronea, and by Brusse (1987Brusse ( , 1988) ) for the Acarosporaceae, of which Sarcogyne is a typical member.
It is as well to state here, that several species of Maro nea [section Pseudomaronea (Miill.Arg.) Magn.], treated by Magnusson (1934), such as Lecanora crassilabra Mull.Arg., have Lecanora-type ascus apices, and are not true Maronea species.
Maronea afroalpina Brusse is presently known only from high altitudes in the Drakensberg, at Mont-aux-Sources.