A new spiny, cushion-like Euphorbia (Euphorbiaceae) from south-west Iran with special reference to the phytogeographic importance of local endemic species

Euphorbia acanthodes Akhani is described as a new gypsophilous species from south-west Iran. The affinity, morphological and carpological features, and habitat of the species are discussed. A list of a further 36 interesting endemic species of south-western Iran and adjacent areas is given with notes on their affinities and distribution. These include Centaurea gudrunensis Boiss. & Hausskn., as a new record from Iran. The specific status of Pteropyrum naufelum Al-Khayat is confirmed and it is suggested that R no anum Boiss. ex Meisn. is synonymous with R aucheri Boiss. The biogeographic importance of the so-called 'Persian foothills', and biodiversity conservation status of the area are discussed, together with distribution maps of 12 species. It is concluded that the majority of the endemic species in the southern and south-western parts of Iran are Irano-Turanian or have their origins in the Irano-Turanian region. Therefore, it is questionable to consider the area as part of either the Saharo-Sindian, Sudanian or Sudano-Zambezian regions. (C) 2004 The Linnean Society of London.