Search

Premise: Southern Africa is a biodiversity hotspot rich in endemic plants and lichen-forming fungi. However, species-level data about lichen photobionts in this region are minimal. We focused on Trebouxia (Chlorophyta), the most common lichen photobiont, to understand how southern African species fit into the global biodiversity of this genus and are distributed across biomes and mycobiont partners., Methods: We sequenced Trebouxia nuclear ribosomal ITS and rbcL of 139 lichen thalli from diverse biomes in South Africa and Namibia. Global Trebouxia phylogenies incorporating these new data were inferred with a maximum likelihood approach. Trebouxia biodiversity, biogeography, and mycobiont-photobiont associations were assessed in phylogenetic and ecological network frameworks., Results: An estimated 43 putative Trebouxia species were found across the region, including seven potentially endemic species. Only five clades represent formally described species: T. arboricola s.l. (A13), T. cf. cretacea (A01), T. incrustata (A06), T. lynniae (A39), and T. maresiae (A46). Potential endemic species were not significantly associated with the Greater Cape Floristic Region or desert. Trebouxia species occurred frequently across multiple biomes. Annual precipitation, but not precipitation seasonality, was significant in explaining variation in Trebouxia communities. Consistent with other studies of lichen photobionts, the Trebouxia-mycobiont network had an anti-nested structure., Conclusions: Depending on the metric used, ca. 20-30% of global Trebouxia biodiversity occurs in southern Africa, including many species yet to be described. With a classification scheme for Trebouxia now well established, tree-based approaches are preferable over "barcode gap" methods for delimiting new species., (© 2024 Botanical Society of America.)

Shifts in climate along elevation gradients structure mycobiont–photobiont associations in lichens. We obtained mycobiont (lecanoroid Lecanoraceae) and photobiont (Trebouxia alga) DNA sequences from 89 lichen thalli collected in Bolivia from a ca. 4,700 m elevation gradient encompassing diverse natural communities and environmental conditions. The molecular dataset included six mycobiont loci (ITS, nrLSU, mtSSU, RPB1 , RPB2 , and MCM7) and two photobiont loci (ITS, rbc L); we designed new primers to amplify Lecanoraceae RPB1 and RPB2 with a nested PCR approach. Mycobionts belonged to Lecanora s.lat., Bryonora , Myriolecis , Protoparmeliopsis , the " Lecanora " polytropa group, and the " L." saligna group. All of these clades except for Lecanora s.lat. occurred only at high elevation. No single species of Lecanoraceae was present along the entire elevation gradient, and individual clades were restricted to a subset of the gradient. Most Lecanoraceae samples represent species which have not previously been sequenced. Trebouxia clade C, which has not previously been recorded in association with species of Lecanoraceae, predominates at low- to mid-elevation sites. Photobionts from Trebouxia clade I occur at the upper extent of mid-elevation forest and at some open, high-elevation sites, while Trebouxia clades A and S dominate open habitats at high elevation. We did not find Trebouxia clade D. Several putative new species were found in Trebouxia clades A, C, and I. These included one putative species in clade A associated with Myriolecis species growing on limestone at high elevation and a novel lineage sister to the rest of clade C associated with Lecanora on bark in low-elevation grassland. Three different kinds of photobiont switching were observed, with certain mycobiont species associating with Trebouxia from different major clades, species within a major clade, or haplotypes within a species. Lecanoraceae mycobionts and Trebouxia photobionts exhibit species turnover along the elevation gradient, but with each partner having a different elevation threshold at which the community shifts completely. A phylogenetically defined sampling of a single diverse family of lichen-forming fungi may be sufficient to document regional patterns of Trebouxia diversity and distribution. [ABSTRACT FROM AUTHOR]

The new genus Burrowsia (Caliciaceae) is proposed to accommodate the new species B. cataractae , which is known from only a single locality in Mpumalanga, South Africa. Burrowsia is characterized by its pigmented, submuriform ascospores and ascus with an apical tube structure, and also by its DNA sequence data that place it outside related buellioid genera. We also describe the new species Scoliciosporum fabisporum, also known from a single locality in Mpumalanga, which differs from all other species of that genus in having distinctive kidney-shaped, 0–1-septate ascospores. It is most closely related to the Northern Hemisphere species S. intrusum, which is here confirmed by molecular data as belonging to this genus in a well-supported Scoliciosporaceae. The potential of the region to yield additional novel lichen taxa is explored. [ABSTRACT FROM AUTHOR]

Peltigera serusiauxii is proposed here as a new species from Papua New Guinea and Sabah, northern Borneo (Malaysia). The species belongs to the polydactyloid clade of section Polydactylon. Because of its large thalli with a glabrous upper surface, this species was previously identified as P. dolichorhiza, but it differs by its polydactylon-type lower surface and the high amount of dolichorrhizin. It appears to be a strict specialist in its association with Nostoc phylogroup IX throughout its known distribution. This is one of many undescribed species remaining to be formally described within the genus Peltigera, especially in Asia and Australasia. [ABSTRACT FROM AUTHOR]

Background In 1868, Nylander described 15 new lichen taxa from collections made near Durban, South Africa. The locality was not specified and the collector was identified only as 'Miss Armstrong'. Objectives To identify the collector and type locality of Nylander's species. Method Scientific literature, maps, letters, notebooks and genealogical sources were consulted to reconstruct the provenance of the specimens. Results 'Miss Armstrong' was likely Olivia Armstrong; she collected in the Karkloof area of the KwaZulu-Natal Midlands. Conclusion This investigation facilitates future work to determine whether the species described and reported by Nylander are still extant in the same locality. [ABSTRACT FROM AUTHOR]

Seventy-four lichen species, identified from both modern and historical vouchers, are reported for Lizard Lick, Wake County, North Carolina. Like many granite flat rock areas in the southeastern United States, the Lizard Lick flora is a unique combination of Piedmont and Coastal Plain species. The Lizard Lick lichen flora shares 24 species in common with two similar, nearby granite flat rock sites, Temple Flat Rock Preserve and Turnipseed Nature Preserve. Species characteristic of granite flat rock habitats were found, including Peltula cylindrica and Pyrenopsis portoricensis; the latter collection represents the second record of this species for North America. [ABSTRACT FROM AUTHOR]

Limestone is a distinctive substrate that has significant effects on soils and plants. The present study characterizes the diversity of vascular plants, bryophytes, and lichens at the Simonton Corner Quarry Preserve, an abandoned limestone quarry in Rockport, Maine, USA, which was in operation in the late 1800s. We document vascular plant diversity and associated edaphic features (i.e., soil pH and elemental chemistry) using 30 5×5 meter plots spread throughout the site. For vascular plants, 114 species in 96 genera and 50 families were observed; few of these species are known to prefer calcareous environments, and 38% are nonnative. Conversely, the soil- and rock-dwelling cryptogam biota, which comprises 21 moss species in 13 families and eight lichen species in three families, contains many calciphilic species. The bryoflora conspicuously lacks liverworts, whereas the lichen biota is dominated by cyanolichens. This study will inform future conservation and reclamation work at this and other human-altered limestone sites in Maine and floristically similar areas and contribute to our understanding of the geoecology of New England. [ABSTRACT FROM AUTHOR]