A species of Euphorbia sect. Esula (Euphorbiaceae) from the Western Tian-Shan, Central Asia, is described as new to science. Euphorbia talassica sp. nova occurs in the Talas Mountain Range in Kazakhstan and Kyrgyzstan, and falls into E. ser. Andrachnoides because of its relatively short and broad leaves. Euphorbia talassica is most similar to E. irgisensis, from which it differs by having a slender and spreading rootstock (vs. a vertical taproot), and incrassate (vs. thin) leaves. The new species also grows at much higher elevations. Euphorbia ser. Andrachnoides is overviewed for Central Asia and adjacent areas, with seven species discussed and mapped.