Despite its modest size, Montenegro(situated within the south-eastern Dinaric karst) stands out as one of the most species-rich countries in Europe. During a botanical expedition in May 2019 on the rocky plateau “Sokolski krši” in the Montenegrin south-eastern Dinaric karst, researchers found a small and geographically restricted population of plants that we could not classify in any known taxon of Lamiaceae.
By molecular phylogenies, along with morphological, cytological and ecological evidence, the researcehers confirmed that the perplexing population of plants represented a new distinct and remarkable monotypic genus of Lamiaceae. They named it as Petrolamium, highlighting its relationship to the subfamily Lamioideae and its distinctive presence in calcareous rock crevices, a unique characteristic that sets it apart from other members of the tribe Lamieae.
Petrolamium is similar to most of the taxa of the tribe Lamieae in that all have trigonous and apically truncated mericarps. However, Petrolamium can be distinguished from other members of Lamieae by its reniform and lobate leaves, pedicellate and small flowers, erect, narrow, strait and emarginated posterior corolla lip, included and glabrous anthers, positioned just below the inner margin of the corolla tube, presence of fatty tissue, unique chromosome number and in habitat preferences.
A single species,Petrolamium crnojevicii, is only known from south-eastern Dinaric karst, southern Montenegro.
Petrolamium crnojevicii is a rhizomatous perennial herb with erect stems. The species is restricted to a narrow area in the south-eastern Dinaric karst. It species is found exclusively in calcareous rock crevices on vertical walls at elevations between 500 and 700 m in floristically depauperate chasmophytic stands composed of (sub)Mediterranean taxa.
“The new species is currently known from a single locality. We considered its conservation status as critically endangered (CR) according to IUCN criteria, due to its extremely small extent of occurrence and area of occupancy within the south-eastern Dinaric karst,” said LI Bo, one of the corresponding authors.
The new genus was publishe in Taxon.
Contact
LI Bo Ph.D Principal Investigator
Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303 China
E-mail: hanbolijx@xtbg.ac.cn
Petrolamium crnojevicii gen. & sp. nov., typically developed plant. Photo: B. Surina.
Macro- and micro-habitat of Petrolamium crnojevicii gen. & sp. nov.
