Euphorbia mongoliensis M. H. Li & C. H. Zhang

Zang, Er-Huan, Zhang, Ming-Xu, Wang, Wen-Le, Zhang, Chun-Hong & Li, Min-Hui, 2021, Euphorbia mongoliensis (Euphorbiaceae), a new species from Inner Mongolia, China, Phytotaxa 501 (1), pp. 151-161: 155

publication ID 10.11646/phytotaxa.501.1.6

persistent identifier

treatment provided by


scientific name

Euphorbia mongoliensis M. H. Li & C. H. Zhang

sp. nov.

Euphorbia mongoliensis M. H. Li & C. H. Zhang   , sp. nov. ( Figs. 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Diagnoses:— The new taxon is distinct from the known species of the genus Euphorbia   in Inner Mongolia. It is similar to E. esula   and E. caesia   in many morphological characters. It is distinguished by a stem height of 2–10(–12) cm, usually less than 10 cm (vs. longer stems of more than 30 cm in E. esula   , 10–30(–50) cm in E. caesia   ); leaves being auriculate at the base, the margins entire and slightly recurved, both sides slightly white farinose (vs. wedged, round or truncate in E. esula   and E. caesia   , not recurved in both). The capsule surface is tuberculate (vs. not tuberculate in E. esula   , glabrous or finely rugose in E. caesia   ) ( Table 2).

Type: — CHINA. Inner Mongolia: Ordos City, Dongsheng District, Jilao Qingchuan Wetland Park , 1431m, 39°48’52.47”N, 109°53’33.57”E. 20 May, 2020, M. H GoogleMaps   . Li & C. H   . Zhang 150602200520001 LY (holotype PE!; isotype HIMC!)   .

Description: —Herbaceous, perennial. Roots cylindrical, branched or not, brown, 20–55 cm × 1.5–3 mm. Stem erect, single or basally branched, 2–10(–12) cm tall, usually less than 10 cm, 1.2–3 mm in diameter, with or without shallow edges, slightly white farinose, puberulent. Leaves oval triangular or oval lanceolate, 1.2–1.5 × 0.2–0.5 cm; apex acuminate or slightly blunt, base gradually wider and auriculate; the margins entire and slightly recurved, both sides slightly white farinose, sessile; midvein prominent. Ray-leaves 6–10, oval triangular or oval lanceolate, 0.4–0.7 × 0.2–0.4 cm, apex blunt or acuminate, slightly auriculate and sessile at the base, semiamplexicaul; 6–10 terminal rays (sometimes have axillary rays), with the same number of ray leaves, from the base of the ray leaves, 0.5–1.5 cm. The apex of each terminal ray often has 1–2 dichasia. The inflorescence is solitary at the apex of a dichasium, and the base is sessile. The base of terminal rays have one pair of subcyathial raylet leaves, triangular broadly ovate, 0.3–0.55 × 0.35–0.65 cm, apex shortly acuminate to rounded, and the base is truncated; cyathium campanulate, 2–3 × 1.5–2.5 mm, smooth, glabrous, 5-lobed on the margin, lobes rounded to oval triangular, tomentose on margin and inside; cyathial glands 4, semicircular, transversely ellipse, reniform or crescent shaped, with or without horns at both ends, yellow brown or dark brown; 2–3 stamens and the ovary stalk exserted from cyathium, ovary ovoid, trilocular, styles 3, completely separate, stigma apex 2-deep lobed. Capsule trigonous globose, 2.5–3.5 × 3.0–4.0 mm, with 3 vertical furrows, glabrous, tuberculate, with a stalk, 1.5 mm long; styles persistent. Seeds ovoid-globose, 2.0–2.5 × 1.0– 1.5 mm, yellow-brown; caruncle present, peltate, sessile.

Phenology: —Flowering and fruiting from May to June.

Distribution and habitat: —Occurs on dry hillsides. It is distributed in Dongsheng District and Kangbashi District, Ordos City, Inner Mongolia. The type was collected from Dongsheng District.

Etymology:—The epithet refers to the area of its occurrence (Inner Mongolia).


Botanische Staatssammlung München


University of Helsinki


University of Copenhagen


Laboratoire de Mycologie associe au CNRS


Institute of Botany, Chinese Academy of Sciences


Inner Mongolia University