Thesium compressum: Red Data Book of Armenia

CR B 1 ab(iii) + 2 ab(iii)

Category. Critically endangered species. Only one sub–population is known. The extent of occurrence and area of occupancy are less than 10 km2. The species is on the verge of extinction caused by changes in habitat conditions in the result of the intensity of agricultural activities. It was included in the first edition of the Red Data Book of Armenia under Category 1: Endangered species. It is not included in the Annexes of CITES and that of the Bern Convention.

Description. Annual plant 15–40 cm, with vertical root and virgate, angulose, compressed branches. Inflorescence spike–shaped, long, thin, lax. Leaves slightly fleshy, 1,5–6 cm long, linear, acuminate. Flowers very small, 1,5 mm long, whitish.

Distribution. In Armenia it grows only in Yerevan floristic region (in the neighborhoods of Ararat town). AOO is 8 km2, the number of locations is 1. Besides Armenia the species occurs in Central Anatolia and North–West Iran.

Ecological, biological and phytocoenological peculiarities. Grows in lower mountain belt, at the altitude of 800–850 meters above sea level, in salt marshes. Flowering from May to July, fruiting from June to August.

Limiting factors. Restricted extent of occurrence and area of occupancy, loss/degradation of habitats caused by the expansion of arable lands, drainage of marshes, grazing and vegetation burning.

Conservation actions. According to the 2008 decree of the Government of RA the marshes of Ararat Plain were marked as "Salt marshes" nature monument, but no actual conservation is implemented. Necessary: monitoring of the population state.