Astragalus physocalyx

Astragalus physocalyx Fisch.

Fabaceae – Pea family

Conservation status. Critically Endangered [CR B2ac(i,ii,iii,v); D]. IUCN(Ex/E), BDA, BC. Tertiary relict.

Morphology and biology. Caespitose, acaulescent perennial. Leaves numerous, imparipinnate, with 15–22 pairs of leaflets. Flowers 1–5, 2–2.5 cm long, pale violet, in a lax raceme. Calyx vesicular-inflated in fruit. Legumes 1-seeded; seeds 3–4 mm. Fl. IV–V, fr. V–VI. Insect pollination, possibly also wind pollination. Reproduction by vegetative means and seeds.

Habitats and populations. Grows in dry grassy and sunny places, on sandy, well developed soil, on siliceous bedrock in the lowlands.

Distribution in Bulgaria. Valley of Struma River (Kartaletsa hill near Kulata village, Petrich district), Thracian Lowland (Dzhendemtepe in Plovdiv, the locality was destroyed); 150–200 m alt. In 1976 six individuals, derived from a single specimen collected near Kulata village and grown in the Botanical Garden in Sofia, were re-planted on Dzhendemtepe. Five of the plants died and only one has survived until now and flowered.

General distribution. Balkan Peninsula (Bulgaria, R Macedonia), Turkey (Anatolia).

Threats. Stone-pitting on Dzhendemtepe and collection of specimens for herbaria as well as planting of an orchard in part of the locality near Kulata led to almost complete extinction of the species.

Conservation measures taken. Protected species with priority conserved habitats by the Biodiversity Act. Included in 1997 IUCN Red List of Threatened Plants and Annex 1 of the Bern Convention (1979). Dzhendemtepe was declared a Protected Site. The locality near Kulata village is in a site of the European ecological network Natura 2000 in Bulgaria. A proposal for designation of this locality as a protected area has been submitted. An Action plan for conservation of the species is in a process of elaboration.

Conservation measures needed. Study on the biology and ecology of the species, and its reproduction; reintroduction of more individuals to the classical locality on Dzhendemtepe; collection of seeds for the National Seed Genebank in Bulgaria.

References. Stanev 1970, 2000; Vălev 1976; Velchev 1984; Vassilev 1992; Nydegger-Hügli 2002; Stoyanov et al. 2006.

Author: Stefan Stanev

Astragalus physocalyx (distribution map)

Astragalus physocalyx (drawing)