Centaurea wagenitziana
Centaurea wagenitziana Bancheva & Kit Tan
Centaurea amplifolia auct. bulg., non Boiss. & Heldr.1, 4, 5
Asteraceae – Daisy family
Conservation status. Critically Endangered [CR B1ab(iii)+2ab(iii); C2(ii)]. BDA.
Morphology and biology. Herbaceous perennial with 60–100 cm long woody stock. Stems 80–150 cm, erect, weakly branched in the upper part, ± densely leafy. Leaves pinnatisect; lower 35–45 cm long, 25–35 cm wide, with 4–6 pairs of elliptic-lanceolate, 15–18 × 5–6.5 cm, dentate segments. Capitula 25–35 mm in diameter. Involucrum globose, 12–15 mm in diameter. Appendages of involucral bracts flame-shaped, broadly crescent, entire or lacerate, 2–5 mm wide toward the apex. Florets pale pink to white, with 5 dark purple veins. Achenes 6–7 mm, yellowish to dark brown; pappus 7–9 mm. Fl. VI, fr. VII. Insect pollination.
Habitats and populations. Grows at margins of Quercus cerris and Q. freinetto forests. The only known population comprises about 450 individuals clustered in small groups. Seed recruitment is low due to their low germination capacity (20% germination rate in experimental conditions) and infection by insects. More than 50% of the population is infected by larvae which develop within the capitula and feed on the achenes.
Distribution in Bulgaria. Toundzha Hilly Country (Derventski hills – north of Golyam Dervent village, Elhovo district); up to 400 m alt. In the past the taxon, erroneously referred to as Centaurea amplifolia, was known from 3 localities: Sakar Mt between Topolovgrad and Planinets village (not recorded there for more than 30 years), and Black Sea coast (southern – Bakarlaka, Sozopol and Mandra village, Burgas district, where the species has not been recorded for more than 70 years).
General distribution. Bulgaria and Turkey.
Threats. Loss of the lowland oak forests in the past decades; construction of a dam near Mandra village; low recruitment and migration potential of the species; specific habitat requirements; massive infection by insects.
Conservation measures taken. Protected species by the Biodiversity Act. Included as Centaurea amplifolia in 1997 IUCN Red List of Threatened Plants as ‘Indetermined’. An Action plan for conservation of the species is in a process of elaboration.
Conservation measures needed. Designation of the locality as a protected area; population monitoring; supporting the reproduction of the species in situ; collection of seeds for the National Seed Genebank in Bulgaria.
Note. In the Bulgarian botanical literature this taxon was erroneously reported as Centaurea amplifolia Boiss. & Heldr.Present studies show the this species does not occur in Bulgaria and Turkey.
References. Dostál 1976; Ninova 1984; Walter & Gillet 1998; Kit Tan et al. 2009.
Author: Svetlana Bancheva
