Vaccinium pseudopubicalyx X. H. Ye, Q. L. Wang & Y. H. Tong, 2022

Ye, Xue-He, Wang, Qing-Long, Huang, Ming-Zhong & Tong, Yi-Hua, 2022, Novelties on the genus Vaccinium (Ericaceae) from Hainan, China: a new species and a new record for the country, PhytoKeys 202, pp. 121-132 : 121

Vaccinium pseudopubicalyx X. H. Ye, Q. L. Wang & Y. H. Tong sp. nov.

Figs 1 , 2 , 3

Type.

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) .

Diagnosis.

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 ).

Description.

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.

Etymology.

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

Vernacular name.

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

Phenology.

Flowering in January-June; fruiting time unknown.

Distribution and habitat.

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.

Taxonomic notes.

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. Vaccinium pseudopubicalyx 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. Vaccinium pseudopubicalyx Eococcus and sect. Vaccinium pseudopubicalyx 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. Vaccinium iteophyllum 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.

Additional specimens examined.

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).

Figures

Figure 1. Vaccinium pseudopubicalyx A habit B trunk C leafy branch D flowering branch. Photos A-C by Y. H. Tong; D by X. H. Ye.

Figure 2. Vaccinium pseudopubicalyx A inflorescence B flower C two bracteoles and one floral bract, adaxial (left) and abaxial (right) view D calyx lobe, abaxial (left) and adaxial (right) view E leaves F opened corolla, adaxial (left) and abaxial (right) view G stamens, lateral (left), abaxial (middle) and adaxial (right) view H anther pores I hypanthium, disk and style with front two calyx lobes removed J ovary, apical (left) and transverse (right) view. Scale bars: 3 cm (E); 1 cm (A, B); 5 mm (F, I); 3 mm (D, G); 2 mm (D, J); 1 mm (H). Photos by X. H. Ye.

Figure 3. Vaccinium pseudopubicalyx A flowering branches B bracteoles, adaxial (left) and abaxial (right) view C floral bract, adaxial view D flower E hypanthium, disk and style with front one calyx lobe removed F calyx lobe, adaxial view G opened corolla, adaxial view H stamens, adaxial view I dorsal anther spurs of antepetalous anthers (left) and antesepalous anthers (right) J ovary, transverse view. Drawn by Mr. D. H. Cui.

Figure 4. The distribution of Vaccinium pseudopubicalyx and V. viscifolium in Hainan Island (China).

Figure 5. Vaccinium pubicalyx and comparison of stamen of V. pubicalyx and V. pseudopubicalyx A young leafy branch of V. pubicalyx B branch with young inflorescences of V. pubicalyx C flowering branches of V. pubicalyx D floral bract of V. pubicalyx, abaxial (left) and adaxial (right) view E stamens of V. pubicalyx (left) and V. pseudopubicalyx (right) F dorsal anther spurs of V. pubicalyx (left) and V. pseudopubicalyx (right). Scale bars: 3 mm (D, E); 2 mm (F). Materials of V. pubicalyx in D-F from G. Forrest 7637 (IBSC 0457011), and those of V. pseudopubicalyx in E-F from type. Photos A, C by H. B. Ding; B by Y. H. Tong; D-F by X. H. Ye.