Centaurea nigrescens
Centaurea nigrescens Willd.
Asteraceae – Daisy family
Conservation status. Critically Endangered [CR B1ab(iii)+2ab(iii)]. BDA.
Morphology and biology. Perennial herbaceous plant. Stems erect, 60–100 cm, with several branches. Leaves greenish, entire or slightly undulate, setose; lower leaves pedunculate, oblong elliptical; upper ones elliptical, elongated at base. Capitula single, 25–30 mm wide. Involucre ovate-cylindrical, 12–14 mm wide. Appendages triangular, not covering completely the bracts, brown-black, with 6–8 pairs of fimbriae. Florets purple. Achenes c. 3 mm. Pappus strongly reduced or absent. Fl. VII–IX, fr. VIII–X. Insect pollination.
Habitats and populations. Occurs in open grassy places in the beech belt. The only population that has been confirmed consists of single individuals.
Distribution in Bulgaria. Balkan Range (central – Karlovo, Gabrovo and Elena regions). The data on the species distribution date from the first half of the 20th century, after which they have not been confirmed. In 1996 single individuals were discovered above the water power station above Karlovo, along the path to Hubavets chalet.
General distribution. C and SE Europe.
Threats. Low reproductive and migration potential of the species; specific habitat conditions.
Conservation measures taken. The species is protected by the Biodiversity Act. The population of the species is within the borders of Central Balkan National Park and in a site of the European ecological network Natura 2000 in Bulgaria.
Conservation measures needed. Study of the biology and ecology of the species and its reproductive potential; monitoring of the population state; elaboration of an action plan; collection of seeds for the National Seed Genebank in Bulgaria.
References. Dostál 1976; Ninova 1984.
Author: Svetlana Bancheva
