Phlomoides zenaidae (Popov)Adylov, Kamelin & Makhmedov, in Opred.Rast.Sred. Azii 9: 101. 1987.

≡ Eremostachys zenaidae Popov, in Nouv. Mem. Soc. Nat. Mosc. xix. 71. 1941.

Type: — Kazakhstan, Eastern Tianshan mountain, Tscharyn river, arid hillsides, 20 June 1937, M. G . Popov. s.n. (holotype: LE!; isotype: LE!).

Perennial herbs, 40–60 cm tall. Roots linear-tuberous. Stems erect, subquadrangular, purple, 1–3 branched, glabrous. Basal leaves with petioles 4–6 cm long, white, margin white pilose; lamina oblong, margin coarsely crenate, thick papery, 10 × 3–4 cm, adaxially green, glabrous, abaxially light green, with sparse, simple and stellate pilose hairs; stem leaves opposite, similar to basal leaves; petioles short, 0.5–1 cm long. Verticillasters 6–10 flowered, distant; floral leaves sessile, rhombus-oblong, subglabrous, margin remotely dentate, shorter than verticillasters, gradually reduced upward; bracts ovate-lanceolate, 6–8 mm long, glabrous, margin sparsely ciliate. Calyx tubular-campanulate, ca. 18 mm long, glabrous outside, teeth subequal, 1.5–2 mm long, apical emarginate, with spines 1–1.5 mm long, tufted hairy inside. Corolla purple, ca. 3.5 cm long, 2-lipped; upper lip ca. 15 mm long, galeate, densely stellate tomentose outside, margin entire, glabrous inside, margin ciliate; lower lip 3-lobed, ca. 20 mm long, flabellate, middle lobe largest, oblong, lateral lobes ovate; tube slender, ca. 18 mm long, annulate pilose inside near base. Stamens 4, included, glabrous, posterior filaments with upwardly curved appendages at base. Style included, apex unequally 2-lobbed. Mericarps elliptic, glabrous (Fig. 1).

Phenology: —Flowering from May to July, fruiting from July to September.

Distribution, habitat and ecology: — China and Kazakhstan; new record for China, occurring in Nilka County, Xinjiang province. It grows on arid gravel hillsides, 1100–1200 m, together with other species, such as Ixiolirion songaricum Ping Yan (1996: 605), Scutellaria przewalskii Juzepczuk (1951: 400), Ziziphora tenuior Linnaeus (1753: 21), etc. (Fig. 2).

Etymology: —The specific epithet refers to a Russian botanist Zinaida Petrovna Bochantseva.

Common name (assigned here): —Xin jiang sha sui (Ǜḋỳffi; Chinese name).

Taxonomic notes: —Morphologically, Phlomoides zenaidae is obviously different from other Chinese species by posterior lip being glabrous inside with an entire margin (vs. posterior lip bearded inside with a denticulate margin).

Conservation status in China: — Phlomoides zenaidae is restricted to one locality in Nilka County, Xinjiang province. In total, approximately 1,000 individuals were found in a semiarid desert grassland. This species maybe easily threatened by habitat lose. Thus P. zenaidae should be classified as Vulnerable (VU: D1) based on the IUCN Red List Categories and Criteria (IUCN 2019).

Additional specimens examined: KAZAKHSTAN: Almaty province, Zhungar Alata, Charin river, 1100 m, 21 May 2019, Ziyoviddin Yusupov & Maxhmudjanov Dilmurod ZD 1134 (KUN!); Zailiyskiy Alatau, eastern end of the Turaigyr ridge, near the Charyn river, rocky slopes, 15 May 1953, V. P . Goloskov s.n. (MW!). CHINA: Xinjiang province, Nilka County, Keling Village, 1200 m, 26 Sep. 2020, J. C . Chi 1265 (KUN!).