Euonymus wui Ma (1997: 97)

Du, Cheng, Zuo, Yunjuan & Ma, Jinshuang, 2013, Revision of three species of Euonymus (Celastraceae) from China, Phytotaxa 109 (1), pp. 45-53 : 45-46

Euonymus wui Ma (1997: 97) . Fig. 1 : A–F.

Type:— CHINA. Yunnan: Malipo County, Chung-dzia , 1900–2100 m, 2 November 1947, K. M . Feng 12708 (holotype A 00135244 !, isotypes: KUN 0413952 !, KUN 0413953 !,, PE 00108332 !, WUK 00208019 !) .

Shrubs or small trees, evergreen, to 8 m tall, DBH to 10 cm; twigs quadrangular. Leaves coriaceous; petiole 4– 6 mm long; blade elliptic or elliptic-obovate, 4–10 × 2–3 cm, base attenuate, margin nearly entire basally, sparsely crenate apically, apex acute or caudate, 0.8–1.5 cm long, lateral veins 5–7 pairs, reticulate before reaching margin, inconspicuous. Inflorescences axillary, paired dichasia; peduncles purple, 4–5 mm long, secondary peduncles 8–12 mm long; branches 3 or 4, dichotomous; each branch with a pair of small bracteoles; bracteoles ovate, 1.5 × 1 mm, apex acute.. Pedicels purple, 2–4 mm long, flowers 20–26 per inflorescence, 4-merous, 12–14 mm in diam. Sepals short ciliate; petals abaxially purple, adaxial surface and disk yellowish green or light purplish red, lighter purplish red in wet habitats, ovate-deltoid, 5–6 × 4–4.5 mm, margin revolute, apex acute; disc 4.5–5 mm in diam., 4-lobed; stamens 4, anthers oblong; ovary superior, stigma rounded; locules 4; placentation axial; ovules 4 per cell. Capsules 1–3(–5) in each infructescence, fusiform to obovoid, 4-angled, 2.5–3 cm long, 0.8–1.4 in diam., base attenuate, apex acute, opening by 4 lobes at maturity; seeds ovoid, 3-4 per locule, covered by orange aril.

Phenology:—Flowering April to May; fruiting August to October.

Specimens examined:— CHINA. Yunnan: Malipo, Tung-ting, 1400–1500 m, 21 November 1947 (fr.), K. M . Feng 13483 ( KUN); Babu Qu, Liziwan , 1450 m, 27 November 1964 (fr.), Q. A . Wu 9898 ( KUN); Xiajinchang Xiang, Daxichang , 1480 m, 13 September 2012 (fr.), C . Du DC 00203 ( CSH); Chapai Forest Farm, 1600 m, 14 September 2012 (fr.), C . Du DC00216 ( CSH) ; Wenshan, Er Qu, Zuodida Shan, 2000 m, 1958 (fr.), H. T . Tsai 8178 ( KUN); Lao-jiun Shan , 2200–2400 m, 13 August 1947 (fr.), K. M . Feng 11214 ( A, KUN, NAS, WUK); 2800 m, 5 April 2012 (fl.), C . Du DC00005 ( CSH); 2380 m, 5 April 2012 (fl.), C . Du DC00015 ( CSH); 2260 m, 5 April 2012 (fl.), C . Du DC00017 ( CSH); 2260 m, 15 September 2012 (fr.), C . Du DC00225 ( CSH) . Guangxi: Napo, without location, no date (fr.), Z . D. Li 602179 ( IBSC) .

Discussion: —The floral features of Euonymus wui were previously unknown. During several field surveys in Malipo and Wenshan counties in southeastern Yunnan, we conducted general observations and made repeated visits to one population of E. wui in Wenshan Nature Reserve. Both flowering and fruiting stages were re-collected from the same individuals in both counties. From comparison with the type specimens and information in the original literature, the floral morphological traits of E. wui were confirmed and supplemented. The ovary of E. wui has four ovules per locule and three or four seeds per locule when fully developed, which suggest its affiliation to its systematic position within section Euonymus subsection Multiovulatae Loesener (1942: 121) series Myrianthi Blakelock (1951: 233) .

Euonymus wui is similar to E. macrocarpus Gamble ex Oliver (1888: 18) and E. myrianthus Hemsley (1893: 210) , especially in the features of the capsule. Euonymus macrocarpus , however, has 5-merous flowers with white petals and capsules; Euonymus myrianthus has the leaf margins serrate, petals yellowish green and capsules to 2 cm long.

Figures

FIGURE 1: Euonymus wui (A–F) and Euonymus pseudovagans (G–H). A, Branch with leaves and inflorescences; B, Flowers (front view); C, Ovary (longitudinal section); D, Ovary (cross section); E, Capsule; F, Portion of open capsules with red arillate seeds; G, Branch with leaves and inflorescences; H, Capsules. A–D from C. Du DC00017, E–F from C. Du DC00203, G from C. Du DC00093, H from C. Du DC00201.Photos by C. Du.