Euphorbia motuogensis M. T. Li, X. Z. Lan, H. P. Deng & W. L. Zheng, 2021

Li, Man-Ting, Lan, Xiao-Zhong, Zuo, You-Wei & Deng, Hong-Ping, 2021, Euphorbia motuogensis (Euphorbiaceae), a new species from Xizang, China, Phytotaxa 527 (2), pp. 107-116 : 108

Euphorbia motuogensis M. T. Li, X. Z. Lan, H. P. Deng & W. L. Zheng , sp. nov. ( Figs. 1–2 )

Type:— CHINA. Tibet: Motuo, the fourth national survey on Chinese materia medica resources, coniferous forest, meadows; 29°41′46.4″N, 95°32′03.95″E, ca. 2600m a.s.l., 2 July 2016, M. T . Li & X. Z . Lan 542624150702036 LY (holotype SWU) .

Diagnosis:— Euphorbia motuogensis is similar to Euphorbia sikkimensis , but it differs by its pileous stems, secondary involucral leaves absent, 3 yellow green cyathophylls, margin entire or concave in the middle and five similar glands.

Herbs, 20–80 cm tall. Root terete, 20–40 cm × 3–5 mm. Stems single or clustered, 3–7 mm thick, mostly unbranched, pileous. Leaves alternate, all but lowermost uniform in size; stipules absent; petiole very short to almost absent; leaf blade ovate-oblong to elliptic, 3–6 × 1.5–2.5 cm, glabrous, base attenuate-cuneate, margin entire, apex obtuse; midrib prominent on both surfaces, lateral veins slender, lateral veins not reaching margin. Inflorescence a terminal pseudumbel; primary involucral leaves usually one round, 5 pecies, even two rounds, the second round involucral leaves usually 3, green, leaves long elliptic to ovate-elliptic, somewhat unequal, 3–4 × 1.5–2.5 cm, base attenuatecuneate, apex obtuse, primary rays 7 (8), 2–4 cm; secondary involucral leaves absent. Cyathophylls 3, yellow green, broad ovate, 1–1.4 × 1–1.2 cm, margin entire or concave in the middle, base and apex rounded. Cyathium; involucre campanulate, ca. 3.5–5× 5–5.5mm, 5 lobes, rounded; glands 5, rounded, densely pilose on the inside. Male flowers many, most exserted from involucre. Female flower: ovary pedicellate and extended out of cup, smooth, glabrous; styles free, style arms slightly 2-lobed. Capsule globose, ca. 5 × 5 mm, smooth, glabrous. Ovary 3-loculed with parietal placentation. Fl. and fr. Jun.–Oct.

Etymology:— The specific epithet refers to Motuo, Tibet, China, the type locality of the new species.

Distribution and Habitat:— Euphorbia motuogensis is currently known only from its type locality, i.e. the fourth national survey on Chinese materia medica resources. It grows at coniferous forest and meadows at an elevation of ca. 2600 m a.s.l.

Phenology:— Flowering and fruiting were observed in June to October.

Additionally specimens examined (paratypes):— CHINA. Tibet: Motuo , M . T . Li, X. Z . Lan 542624150702037 LY ( SWU)

Figures

FIGURE 1. Euphorbia motuogensis. A. Flower plant; B. Cyathium; C. Grand; D. Male flower; E. Styles; F. Female flower. (Drawn by Y. B. Sun)

FIGURE 2. Euphorbia motuogensis. A. Flowering plant; B. Inflorescence a terminal pseudumbel; C. Pileous stem; D. Cyathophylls and cyathium; E. Cyathium; F. Grand; G. Male flower; H. Female flower; I. Styles; J. Capsule.