First supplement to the lichen checklist of South Africa

Peer reviewe

Isalonactis, a new genus of Roccellaceae (Arthoniales) from southern Madagascar

AbstractThe new genus and speciesIsalonactis madagascariensisis characterized by a crustose, non-corticate, often sorediate thallus containing psoromic acid, tiny white pruinose ascomata with a thalline margin, an inconspicuous excipulum, a pale brown hypothecium, 3-septate hyaline ascospores and curved filiform conidia. Phylogenetic analyses using nuLSU andRPB2sequences placeIsalonactisin theRoccellaceae, close to the generaLecanactisandChiodecton. The new species was collected on sheltered siliceous rocks in the dry landscape of the Isalo Massif (S Madagascar).Dermatiscum thunbergiiis newly recorded from Madagascar.</jats:p

A comparison of the physiology, anatomy and ribosomal DNA in alpine and subalpine populations of the lichen Nephroma arcticum- the effects of an eight-year transplant experiment

Thalli of Nephroma arcticum were transplanted between and within a high-elevation alpine heath (1100 m) and a low-elevation subalpine mountain birch forest (380 m) in northern Swedish Lapland and harvested after eight years. Statistically significant differences (P < 0.05) were found between control samples for dark respiration rates, photon use efficiencies (apparent quantum yields) and light compensation points (all were higher in the high-altitude population). The following traits were significantly affected by transplanting: (1) epicortex thickness, (2) upper cortex thickness in the low-altitude population, (3) maximum photosynthetic rates, (4) dark respiration rates and (5) light compensation point. Of these malleable traits, all reduce the differences between the controls although there seems to be over-compensation in maximum net photosynthesis and under-compensation in dark respiration rate of the low-altitude population. Conservative traits, i.e., those that did not change significantly with transplantation were: (1) thallus thickness, (2) algal layer thickness, (3) algal cell diameter and (4) light saturation level. Small, yet significant differences in anatomy and physiology suggest that an ecotypic differentiation was established although the two internal transcribed DNA spacers ITS 1 and ITS 2 showed no corresponding variation between the populations

Four new species of Arthothelium (Arthoniales, Ascomycetes) from Africa and Socotra

Abstract: Four species of Arthothelium from Africa and Socotra are described as new to science: Arthothelium atrorubrum from Madagascar, characterized by irregularly rounded blackish ascomata with a deeply red hypothecium and submuriform ascospores; Arthothelium aurantiacopruinosum from the Democratic Republic of the Congo, characterized by black, irregularly rounded to stellate, orange pruinose ascomata and muriform ascospores with two larger terminal cells; Arthothelium frischianum from Madagascar, characterized by brownish-black minute irregular ascomata with remnants of thallus and muriform ascospores with one larger terminal cell; Arthothelium miesii from Socotra (Yemen), characterized by a thick thallus, immersed, stellate to cerebriform, brownish, greyish pruinose ascomata and submuriform ascospores. A key to all reported species of Arthothelium from tropical Africa (South Africa excluded) and Socotra is provided

Seasonal Dynamics of Arbuscular Mycorrhizal Fungal Communities in Roots in a Seminatural Grassland▿ †

Symbiotic arbuscular mycorrhizal fungi (AMF) have been shown to influence both the diversity and productivity of grassland plant communities. These effects have been postulated to depend on the differential effects of individual mycorrhizal taxa on different plant species; however, so far there are few detailed studies of the dynamics of AMF colonization of different plant species. In this study, we characterized the communities of AMF colonizing the roots of two plant species, Prunella vulgaris and Antennaria dioica, in a Swedish seminatural grassland at different times of the year. The AMF small subunit rRNA genes were subjected to PCR, cloning, sequencing, and phylogenetic analysis. Nineteen discrete sequence types belonging to Glomus groups A and B and to the genus Acaulospora were distinguished. No significant seasonal changes in the species compositions of the AMF communities as a whole were observed. However, the two plant species hosted significantly different AMF communities. P. vulgaris hosted a rich AMF community throughout the entire growing season. The presence of AMF in A. dioica decreased dramatically in autumn, while an increased presence of Ascomycetes species was detected