A radical shift in the taxonomy of Lepraria s.l.: molecular and morphological studies shed new light on the evolution of asexuality and lichen growth form diversification

A combination of molecular phylogenetic analyses of ITS and mtSSU sequences, morphological and chemical analyses were used to investigate the lineages nominally included in the sterile lichen genus Lepraria. A core group (Lepraria s. str.) was resolved as sister to Stereocaulon. Species producing the secondary compounds argopsin, pannarin and usnic acid were found to belong to other lineages of lichen-forming ascomycetes. Study of Leprocaulon revealed that all species, except the type, likely represent members of Lepraria s. str. that have evolved a fruticose growth form. The correct name for the type species of Leprocaulon is shown to be L. quisquiliare, not L. microscopicum, and the genus is redefined to include several species previously placed in Lepraria. Leprocaulon quisquiliare is also shown to comprise two morphologically convergent species. The name is lectotypified and epitypified on material from the type region (Germany) and its application restricted to Old World population...

本研究结合内转录间隔区（Internal Transcribed Spacer, ITS）与线粒体小亚基（mitochondrial small subunit, mtSSU）序列的分子系统发育分析、形态学与化学分析，对名义上归入无菌地衣类粉衣属（Lepraria）的演化支开展了系统调查。核心类群（粉衣属狭义类群，Lepraria s. str.）被解析为与珊瑚枝属（Stereocaulon）互为姊妹群。能够产生次生代谢产物argopsin、pannarin与松萝酸（usnic acid）的物种，实则隶属于地衣型子囊菌的其他演化支。对杆衣属（Leprocaulon）的研究表明，除模式种外，该属所有物种均属于粉衣属狭义类群，仅演化出了枝状生长型。研究证实，杆衣属的模式种正确学名为L. quisquiliare，而非L. microscopicum；同时该属被重新界定，纳入此前归入粉衣属的多个物种。杆衣属Leprocaulon quisquiliare实则包含两个形态趋同的物种。该分类群基于模式产地（德国）的标本完成了后选模式指定与附加模式指定，其应用范围被限定于旧世界种群……