China, Hainan, Wuzhishan City, Wuzhi Mountain, montane summit scrub, 18.89°N, 109.69°E,1867 m a.s.l., 20 March 2020, Yi-Hua Tong, Xue-He Ye, Xin-Ting Ma & Qing-Long Wang YXH-18 (holotype: IBSC; isotypes: IBSC, ATCH).

Vaccinium pseudopubicalyx is morphologically similar to V. pubicalyx and its varieties, but can be distinguished by having fewer pairs of secondary veins (3–5 (Fig. 2E) vs. 5–9 (Fig. 5A, B)), smaller (2–3.5 × ca. 1 mm vs. 5–8 × ca. 1.5–2 mm) and lanceolate (vs. ovate) floral bracts, young twigs and inflorescences rachis white-pubescent (vs. brownish-tomentose), and anthers with smaller dorsal spurs (0.5–1 mm vs. ca 4 mm, Fig. 5F).

Evergreen terrestrial shrubs or small trees, 2–4 m tall; much branched, young twigs pubescent, glabrescent. Petioles 3–5 mm long, pubescent; blades elliptic or ovate, 2.2–5 × 0.8–1.9 cm, chartaceous, glabrous on both sides, midvein prominent on both sides, pubescent, glabrescent abaxially, secondary veins 3–5 pairs, visible in vivo, inconspicuous adaxially and slightly raised abaxially when dry, base broadly cuneate, margin serrulate, apex acuminate, shortly caudate. Perennating buds monomorphic. Inflorescence pseudo-terminal or axillary on distal part of twigs, racemose, with 10–13 flowers, rachis 1.4–2.5 cm long, densely pubescent; floral bract caducous, 1, inserted at the base of pedicel, lanceolate to linear, 2–3.5 × ca. 1 mm, glabrous adaxially, pubescent abaxially, margin entire, ciliate; bracteoles 2, unequally inserted at the lower part of pedicel, long ovate-triangular to linear, 1–1.6× ca. 1 mm, glabrous adaxially, pubescent abaxially, margin entire, ciliate; pedicel articulated between pedicel and calyx, 3–4.5 mm long, densely pubescent. Hypanthium cupuliform, 1–2 × 1.5–2 mm, pubescent; calyx lobes triangular to broadly triangular, 1–2.5 × 1–1.5 mm, glabrous adaxially, pubescent abaxially, margin entire, ciliate. Corolla white, tinged with red, tubular, sometimes slightly urceolate, 4.5–8 × 3.5–4.5 mm, pubescent outside, pilose inside; corolla lobes slightly reflexed, small, triangular, 1–1.8 × 1–1.5 mm; stamens 10, dimorphic, 4.5–5 mm long, filaments 2–3 mm long, densely pilose, anthers dorsifixed with 2 minute spurs, ca. 2.5 mm long, thecae ca. 1 mm long, papillate, spurs on antesepalous anthers ca. 0.1 mm long, those on antepetalous anthers ca. 0.05 mm long, inconspicuous, tubules 1.5–2 mm long, 1.5–2 times as long as anther thecae, apex poricidal, pores 0.45–0.6 mm long, teeth absent; ovary inferior, pseudo-10-locular, disk disciform, 10-ridged, pilose, style cylindrical, 6–6.5 mm long, glabrous, stigma punctate. Fruits not seen.

The specific epithet pseudopubicalyx, a noun in apposition, alludes to close alliance to Vaccinium pubicalyx.

拟毛萼越橘 (Chinese pinyin: nǐ máo è yuè jú).

Flowering in January–June; fruiting time unknown.

Vaccinium pseudopubicalyx has been found at four localities in Hainan, viz. the type locality, Bawangling National Nature Reserve (19.12°N, 109.08°E), Jianfengling Tropical Forest Nature Reserve (18.72°N, 108.91°E) and Yinggeling National Nature Reserve (19.18°N, 109.45°E) (Fig. 4). It grows in montane forests or scrub on the mountain summits at elevations from 1122 to 1867 m.

Besides the differences mentioned in the diagnosis, Vaccinium pseudopubicalyx and V. pubicalyx are strictly allopatric: the former one is endemic to Hainan, while the other one is distributed in southwest China and Myanmar.

The new species has also been occasionally identified as V. bracteatum var. chinense (Champ. ex Benth.) Chun ex Sleumer (Zhang et al. 2007; Xing et al. 2012). It can be easily separated from V. bracteatum var. chinense by its inconspicuous (vs. prominent) secondary veins on adaxial surface of leaf blade. Besides, the elliptic or ovate (vs. rhombic-elliptic or lanceolate-elliptic) leaf blades with fewer pairs of secondary veins (3–5 vs. 5–7), shorter inflorescence rachis (1.4–2.5 cm vs. 4–10 cm), smaller (2–3.5 × ca. 1 mm vs. 5–20 × 1–3 mm), entire (vs. serrated) and lanceolate to linear (vs. ovate to oblong-ovate) floral bracts, and different ratio of the length of anther tubules to anther thecae (1.5–2 vs. 2–2.5) can also separate the new species from V. bracteatum var. chinense.

Vaccinium pseudopubicalyx should be assigned to sect. Eococcus Sleumer, because its morphological characteristics match well with those of that section, such as a terrestrial habit, serrate leaf blades, axillary racemes with elongate rachis, deciduous bracts, articulation between hypanthium and pedicel, spurred anthers and a pseudo-10-locular ovary. According to Sleumer (1941), the main difference between sect. Eococcus and sect. Bracteata Nakai is that the former has caducous bracts during anthesis, whereas the latter has persistent ones. However, when examining specimens of V. iteophyllum Hance, a widespread species (distributed in almost every province in southern China) placed in sect. Eococcus by Sleumer (1941), we observed that some populations (e.g., Y. H. Tong & L. Bai 12062414, IBSC) also have persistent bracts even when fruiting. Thus, the delimitation of the two sections appears to not be natural, and the relationship of the two sections needs further study.

Vaccinium pseudopubicalyx (paratypes): China. Hainan: Baisha County, Yuanmen Town, Yinggeling National Nature Reserve, main peak, 31 May 2005 (fl.), F. W. Xing, Rong-Jing Zhang & Yu-Shi Ye 16371 (IBSC); ibid., same date as above, Sai-Chit Ng 5766 (HK, not seen); Changjiang County, Bawangling National Nature Reserve, mountain top, 1380 m a.s.l., 6 January 1964, Pei Zeng 13511 (HITBC); ibid., the second peak (Axe Peak), 27 April 1988 (fl.), Ze-Xian Li & Fu-Wu Xing 4004 (IBSC0528562); ibid., the second peak (Axe Peak), June 1983 (fl.), Guo-Ai Fu 3408 (IBSC0420642); Ledong County, Jianfengling Tropical Forest Nature Reserve, 1400 m a.s.l., 25 January 1984 (fl.), Shi-Man Huang 306 (IBSC0420202); ibid., the second peak, 1220 m a.s.l., 29 November 1957, Qi-Cai He 90777 (IBSC0420580).

Vaccinium pubicalyx: China. Yunnan: Tali [Dali Profecture], Houang-kia-pin [Huangjiaping], 4 July 1888, P. J. M. Delavay 3311 (syntypes: P04484707, image; P04484708, image; P04484709, image; L008184, image); [Tengchong City], hills at the north end of the Tengyueh Valley, May 1912, G. Forrest 7637 (IBSC0457011; K00780601, image; E00327780, image; E00327781, image).

Vaccinium bracteatum var. chinense: China. Hong Kong: Champion s. n. (K00780589, image).

Malaysia, Perak, Scortechini 405 (lectotype CAL, not seen, designated by Sleumer in 1961: 84; isolectotypes BM000996430, image!, K, not seen, P00647874, image!)

Evergreen terrestrial shrubs or trees, up to 6 m tall; young twigs pubescent, glabrescent. Petioles flat, 0.5–1.2 cm long, pubescent; blades elliptic, oblanceolate, obovate or oblong-obovate, 4.8–11.1 × 1.3–3.4 cm, coriaceous, stipitate-glandular on both sides, pinnipalmate, midvein prominent abaxially, flat or slightly sunken adaxially, secondary veins 3–6 pairs, in vivo visible adaxially, flat or slightly raised, inconspicuous abaxially, in sicco inconspicuous on both sides, apex obtuse or rounded, margin entire, slightly revolute, with 1–3 pairs of glands at the basal part, base attenuate, extended. Perennating buds monomorphic. Inflorescence axillary, racemose, with 11–18 flowers; rachis 3.8–5 cm long, sparsely stipitate-glandular; bract caducous, 1, inserted at the base of pedicel, ovate or lanceolate, 9–16 × 3–6.5 mm, glabrous, margin entire, involute; bracteoles oppositely inserted at the base of pedicel, 2, linear, 1.5–2.5× ca. 0.5 mm, glabrous on both sides, margin entire, ciliate; pedicel articulated between pedicel and calyx, 3–5.5 mm long, glabrous. Hypanthium cupuliform, 2–2.5 × 2.5–3 mm, glabrous; lobes triangular to broadly triangular, 1–2.5 × 1.5–2 mm, glabrous on both sides, margin ciliate. Corolla pinkish to white, cylindric-urceolate, 8–10 × 4–5 mm, glabrous on both sides; lobes reflexed or slightly spreading, small, ovate or triangular, 1.5–2 × 1.5–2 mm, glabrous abaxially, papillate adaxially; stamens 10, dimorphic, 6–7 mm long, filaments swollen at base, 3–3.5 mm long, densely pilose, anthers without dorsal spurs, 3–3.5 mm long, thecae 1–1.5 mm long, papillate, tubules 1.5–2.5 mm long, 1.5–2 times as long as anther thecae, apex poricidal, pores ca. 0.5 mm long, antesepalous anthers with 1 tooth at apex of anther tubules, antepetalous anthers with 2 teeth at apex of anther tubules, teeth ca. 0.5 mm long; ovary inferior, pseudo-10-locular, disk disciform, 10 ridged, glabrous, style cylindrical, 0.8–0.9 cm long, glabrous, stigma truncate. Young fruits glaucous, subglobose, persistent calyx lobes incurved, nearly covering disk.

槲寄生叶越橘 (Chinese pinyin: hú jì shēng yè yuè jú).

Vaccinium viscifolium is distributed in China (Hainan, Fig. 4), Southern Indochina to Peninsular Malaysia. So far, Hainan is the northernmost distribution locality of this species. It grows on open limestone of mountainsides or mountain ridges in montane forests at an elevation of ca. 750 m in Hainan.

Vaccinium viscifolium has two varieties, viz. the nominate variety and V. viscifolium var. bicalcaratum Sleumer. The latter differs from the former by having leaves with a shortly (ca. 1 cm) and obtusely attenuate (vs. obtuse or rounded) apex and anthers with (vs. without) 2 distinct dorsal spurs (Sleumer 1967). The plants from Hainan should belong to the nominate variety, as they have leaves with an obtuse or rounded apex and anthers without dorsal spurs.

Vaccinium viscifolium was initially assigned to sect. Euepigynium Schltr. by Sleumer (1941). However, when compiling Flora Malesiana, he reassigned it to sect. Bracteata, which was recognized with an extremely broad sense to include 163 species consisting of members from several sections, such as sect. Bracteata s.s., sect. Nesococcus H. F. Copel., and sect. Euepigynium (Sleumer, 1967). Stevens (1969) pointed out that the leaves of the species of sect. Euepigynium with an entire margin and plinerved venation were very different from those of sect. Bracteata, which have a serrate margin and pinnate venation. Vander Kloet and Dickinson (2009) also treated sect. Euepigynium and sect. Bracteata as two distinct sections. Moreover, the marginal or basal glands often occur to sect. Euepigynium, and are absent in the species of sect. Bracteata s.s. without exception. Thus, we do not adopt Sleumer’s broad sense of sect. Bracteata (Sleumer, 1967), and prefer to agree with the assignment of V. viscifolium to sect. EuepigyniumSleumer (1941). Whereas sect. Euepigynium is only found in Malesiana and Indochina formerly, Vaccinium viscifolium is the first species of sect. Euepigynium reported from China.

Vaccinium viscifolium: China. Hainan: Ledong County, the ridge of Mazui Mountain, 18.61°N, 109.38°E, 750 m a.s.l., 23 March 2020, Yi-Hua Tong, Xue-He Ye & Ming-Zhong Huang YXH-29 (IBSC).

A key to the species of Vaccinium from Hainan Province is provided below.