Rhododendron baihuaense Y. P. Ma, 2013

Ma, Yongpeng, Wu, Zhikun, Xue, Ruijuan, Tian, Xiaoling, Gao, Lianming & Sun, Weibang, 2013, A new species of Rhododendron (Ericaceae) from the Gaoligong Mountains, Yunnan, China, supported by morphological and DNA barcoding data, Phytotaxa 114 (1), pp. 42-50 : 47-49

Rhododendron baihuaense Y. P. Ma , sp. nov. ( Figs. 2 – 3 )

Rhododendron baihuaense Y. P. Ma resembles R. hanceanum Hemsl. , but differs from R. hanceanum in the absence of scales in both sides of the mature leaf, and only 2–5 flowers per inflorescence; in R. hanceanum the scales are approximately 2–4 times of the scale diameter underside of mature leaf, and there are 7–9 flowers per inflorescence.

Type:— CHINA. Yunnan: Baihualing, Gaoligong Mountains, Baoshan , ca. 2600–2700 m, 28 February 2012 (fl), Y. P . Ma M12-002 (holotype: KUN!; isotype: KUN!) .

Shrub, evergreen, 1–2 m tall; branchlets scaly. Petiole 4–8 mm; leaf blade leathery, ovate-lanceolate to obovate, 6–9 × 2–4 cm, base tapering to broadly cuneate or rounded, margin entire, apex acuminate with a conspicuous drip tip, abaxial surface pale green, white densely scales in young leaves and absent in mature leaves. Inflorescence terminal, racemose, 2–5-flowered; rachis to 10 mm. Pedicel 1.8–2.2 cm, scaly; calyx 5- lobed, lobes pink, 5–8 mm, ovate-oblong to lanceolate, persistent in fruit, densely scaly abaxially, margin ciliate; corolla funnel-shaped, white, 1.8–2.4 cm, outer surface sparsely scaly, inner surface sparsely pilose at base; stamens 10, 1– 3 cm long but of unequal lengths in a single flowers, filaments pilose towards base; ovary densely scaly; style slender, longer than stamens and corolla, glabrous. Capsule long-cylindric, 8–11 mm, densely scaly.

Distribution and ecology:—To date, Rhododendron baihuaense has only been found from a single locality in the region of Baihualing (25°17.3’’N; 98°44.5’’E), Gaoligong Mountains, Baoshan, Yunnan, China. The species has been found in evergreen broadleaf forests at an elevation of 2600–2700 m ( Figure 1 ).

Phenology: — Rhododendron baihuaense flowers from February to March and specimens setting fruits were collected in October.

Etymology: —The specific epithet refers to the site (Baihualing) where the new species was discovered and collected.

Conservation status: —In last three decades, several biodiversity surveys have been carried out in the Gaoligong Mountains with many plant specimens collected - including those of Rhododendron . We have examined all specimens of Rhododendron collected from Gaoligong Mountains and adjacent regions, and no additional localities of the new Rhododendron species described here were found outside the type locality. Whilst we assume that the new species may have a restricted distribution, we are unable to make a strong conservation assessment due to the limited information we currently have regarding the population, distribution etc. of R. baihuaense . Thus DD is given here to the conservation status of the new species.

Additional specimens examined: — China. Yunnan: Baihualing, Baoshan city, 16 October 2011, Y. P. Ma

& J. Nielsen, M11-010 ( KUN!); ibid., 02 March 2012 , Y. P. Ma, M12-001 ( KUN!) .

Figures

FIGURE 1. Geographical distribution of Rhododendron baihuaense, R. hanceanum and R. genestierianum (detailed distribution information of these 3 species were obtained from Chinese Virtual Herbarium, http://www.cvh.org.cn).

FIGURE 2. Rhododendron baihuaense. A, Flowering shoot. B, Scales. C, Flower. D, Mature fruit. E, Pistil and calyx. F, Stamen. G, Corolla, cut open.

FIGURE 3. Rhododendron baihuaense. A, Habitat. B, Leaves. C, Flowers. D, Fruits.