A calciphilous, light-loving terricolous species, rare and less known in the Czech Republic. The lichen has a granular-verrucose, grey-green thallus and relatively large, mostly dark-coloured apothecia (often over 0.5 mm in diameter). These are variable in colour (only green pigments are missing), have a well-defined margin and are constricted at the bases. Within the broadly defined Bacidia genus, B. herbarum has relatively thin filiform ascospores, acicular on one side. Therefore, it resembles members of the genus Bacidina, thought these usually form much smaller fruiting bodies and finer thallus, often with many goniocysts. Microscopically, B. herbarum differs, among others, in the exciple structure.
As its name suggests, this species overgrows plant debris or dying mosses on calcareous soil in both natural and anthropogenic habitats. During a herbarium revision, Vězda (1961) found only one correctly identified specimen, collected by V. Kuťák in the Černý důl valley in the Krkonoše Mountains at the beginning of the 20th century. All the other Czech specimens were wrongly determined. Later, another specimen was found in the material of M. Svrček. It was collected from soil on a small wall in the Průhonice park in 1955 (Liška & Vězda 1990). Other more recent records are known from limestones in the Český kras karst, Pálava Hills and Podyjí National Park.
Literature: Vězda A. (1961): Doplňky k rozšíření lišejníků na Moravě. – Sborník Klubu Přírodovědeckého v Brně 33: 61–69. Liška J. & Vězda A. (1990): Lišejníky Průhonického parku u Prahy. – Preslia 62: 293–306.taxonomic classification:
All records: 7, confirmed 6. One click on a selected square displays particular record(s), including their source(s).