Vaccinium glaucorubrum (C.Y.Wu) Y.H.Tong & P.W.Fritsch

Tong, Yihua, Fritsch, Peter W., Huong, Nguyen Thi Thanh, Averyanov, Leonid V., Kuznetsov, Andrey N., Kuznetsova, Svetlana P. & Nuraliev, Maxim S., 2022, Novelties in Vietnamese Craibiodendron, Lyonia and Vaccinium (Ericaceae), Phytotaxa 538 (1), pp. 21-34 : 26-30

Vaccinium glaucorubrum (C.Y.Wu) Y.H.Tong & P.W.Fritsch , comb. et stat. nov. ( Fig. 3 )

Basionym: — Vaccinium gaultheriifolium var. glaucorubrum C.Y.Wu in Fang & Wu (1987: 379). Fang (1991: 85), Huang & Fang (1991: 328), Fang et al. (2005: 481), Hummer et al. (2017: 422, Fig. 6).

TYPE: —[ CHINA.] Yunnan Province: Maguan Xian , hill slope, in deciduous shrubs, 1800–2560 m, 28 July 1961 , S. K. Wu 61-3574 (lectotype, designated here: KUN: 1208884!; isolectotype: KUN: 1208885!) [ T] .

Description

Shrubs, terrestrial or sometimes epilithic, evergreen, to 4 m tall, without tuber-like structures at stem base, profusely branched. Mature branchlets ± terete but irregularly ridged, brown, 1.5–4.0 mm in diam., lenticellate, glabrous; epidermis grayish, not peeling; perennating buds dimorphic, one per leaf axil, with multiple overlapping scales; the larger scales ovoid, 4.7–7.3 mm long. Leaves alternate, distichous, evenly scattered; petiole 6–11 mm long × 2–3 mm in diam. at base, slightly dilated distally, glabrous; leaf blade broadly elliptic, broadly lanceolate, or ovate-elliptic, larger blades on each branchlet 8.0–11.2 × 3.5–6.7 cm, 1.3–3.0 times as long as wide, subcoriaceous, adaxially green in vivo and green to brown in sicco, abaxially light green or greenish white and glaucous in vivo and light green to light brown in sicco, both surfaces dull, glabrous; base broadly cuneate or broadly rounded to slightly cordate; margin entire, slightly revolute, with one sessile basal gland 0.5–0.7 mm in diam. per side, occasionally another smaller gland present more distally along margin; apex caudate-acuminate to acuminate; midvein raised on both sides; secondary veins pinnately arranged, slightly raised on both sides, 7–9 on each side of midvein, more or less arcuate-ascending, basal veins reaching margin, apical veins meeting in a closed loop near margin; tertiary veins slightly raised or planar and obscure adaxially, slightly raised abaxially.

Inflorescences axillary (occasionally appearing pseudoterminal), indeterminate (racemose and developing mostly beyond the confines of the perennating buds), 1 per axil, 2.0– 3.5 cm long at anthesis, 1- to 15-flowered; peduncle absent or very short; rachis green or flushed red in vivo, 1.2–2.0 mm in diam., glabrous; bracts caducous, rhomboid, cucullate, white or flushed pink in vivo, 8.8–11.0 × 2.1–4.0 mm, glabrous, margin entire, ciliolate, apex acute or slightly acuminate. Flowers pendent, articulated with pedicels, 5-merous, 9–13 mm long. Pedicels magenta, occasionally slightly glaucous, the proximal ones to 11 mm long, gradually shorter distally (to ca. 3 mm), at anthesis 0.6–0.7 mm in diam. medially, slightly dilated distally, glabrous; bracteoles 2, attached at base of pedicel (or slightly above), subopposite, caducous, linear, white in vivo, ca. 4.5 × 0.5–0.6 mm, glabrous, margin entire, apex ciliolate. Calyx (excluding ovary) erect, cupuliform, dull magenta in vivo, glaucous basally, 1.5–1.9 mm long, glabrous; connate portion (tube) 0.5–0.7 mm long; lobes 5, appressed to corolla, deltoid, 0.9–1.5 × 1.1–1.4 mm, glabrous on both sides, margin entire, smooth (e.g., without sessile glands or cilia), apex acute, without terminal gland. Corolla in bud closed and 5-ribbed in line with petal midveins on distal 3/4, deep pink; gamopetalous for ca. 85% length, cylindrical or cylindrical-urceolate, at anthesis pale pink toward base and along petal midveins, deep pink-red in distal half between midveins and maroon to blackish toward lobe margins, 7.6–11.0 × 2.4–3.5 mm, scattered white-hirtellous on lobes inside, otherwise glabrous; lobes 5, recurved in vivo, erect to recurved in sicco, deltoid-ovate, 1.5–2.0 × 1.1–1.3 mm, apex obtuse. Stamens 10, monomorphic (or slightly dimorphic with respect to spur length and angle of spur attachment), free from corolla, included in corolla, distinct from each other except slightly conjoined by lateral sides of thecae, ca. 7.5 mm long; filaments slightly incurved, bright pink in bud and becoming almost white during anthesis, ca. 5 mm long, evenly white-hirtellous throughout, trichomes to 0.4 mm long; anthers dorsifixed, white in bud, 3.4–3.7 mm long, each with 2 spurs; thecae ca. 2 mm long, smooth, eglandular; tubules parallel, ca. 1.5–1.8 mm long, opening by strongly oblique ventral apical pores 1.0– 1.5 mm long, pore apex acute; spurs borne dorsally at base of tubules, straight, oriented at ca. 30° to 45° angle from floral axis. Ovary inferior, cupuliform, terete in cross section, green or flushed red in vivo, glaucous, 1.5–1.9 × 1.4–1.6 mm, 5-locular with 5 incomplete false septa protruding to ca. 1/3 of each locule; disk annular, slightly smaller than ovary, glabrous; style pink to pinkish-white (paler toward base), ± even with bases of corolla lobes or slightly exceeding them (but never exserted from open corolla), ca. 9 mm long, whitehirtellous apically and otherwise glabrous. Infructescences up to ca. 5 cm long. Fruit (berry) globose, blue, glaucous, 4.8–6.9 × 3.9–5.8 mm excluding calyx, fleshy, glabrous, pseudo-10-locular, bearing persistent erect calyx 1.0– 1.7 mm long; disk ca. 1/3 width of fruit. Seeds ovoid to conical, 0.9–1.3 × 0.5–0.7 mm; testa yellowish brown, reticulate, soft.

Nomenclatural notes: —In the original description of V. gaultheriifolium var. glaucorubrum, Fang & Wu (1987) indicated the collection Wu 61-3574 as a type, and KUN as the only herbarium of deposition of this collection. We have found two duplicates of Wu 61-3574 in KUN matching the detailed description and specimen label information included in the protologue. These duplicates should be treated as syntypes in accordance with Art. 9.6 of ICN ( Turland et al. 2018). We selected the specimen with the barcode 1208884 as the lectotype following Arts. 9.3 and 9.11 of ICN ( Turland et al. 2018) as it bears numerous flowers, and has already been labeled in shed. as a type or a holotype by various researchers, including R.C. Fang. The other specimen (1208885) is an isolectotype.

Taxonomic notes: —Both type specimens as well as the paratype in KUN were annotated on 29 June 1965 by C.Y. Wu as “ Vaccinium glauco-rubrum C.Y.Wu , sp. nov. ”, indicating that Wu initially intended to treat this entity as a distinct species. Here, we revive this view based on the study of more ample material, and formally publish the new combination to accommodate Wu’s taxon at species rank. Vaccinium glaucorubrum differs from V. gaultheriifolium ( Griffith 1854: t. 512) Hook.f. ex C.B. Clarke (1882a: 453) s.s. ( V. gaultheriifolium var. gaultheriifolium prior to our publication here; Fig. 4 ) in having a petiole 6–11 mm (vs. 4–7 mm) long, a completely glabrous leaf blade (vs. a sparsely glandular-setose blade on the midvein abaxially) with an entire (vs. minutely denticulate) margin, 1 or rarely 2 (vs. 3) basal glands per side of the leaf blade, adaxially slightly raised or planar and obscure (vs. often conspicuously raised) tertiary veins, pedicels to 11 mm at raceme base and to ca. 3 mm at raceme apex, resulting in an elongate inflorescence shape (vs. pedicels 6–12 mm, resulting in a corymb-like inflorescence shape), corolla 7.6–11.0 mm (vs. 6–7 mm) long, and stamens ca. 7.5 mm (vs. ca. 4 mm) long ( Table 1 ).

The geographical evidence ( Fig. 5 ) shows that the taxa in question are strictly allopatric. Vaccinium glaucorubrum is distributed in SE Yunnan and N Vietnam (see below), whereas V. gaultheriifolium s.s. is a strictly Himalayan species, known from NE India (including Sikkim), Nepal, Bhutan, Myanmar and China (SE Tibet, NW Yunnan) ( Sleumer 1941, Long & Rae 1991, Fang et al. 2005). Specimens of V. gaultheriifolium examined by us are listed in the Appendix.

Additional specimens examined:— CHINA. Yunnan Province: Wenshan County, Xiaojie Town, Laojunshan, hill slope, 2200 m, 23 February 1990, T.L. Min, H. Sun 426 ( KUN: 0233303) [1]; Yunnan Province: Wenshan County, Laojunshan Forest Station, Xiaoyantou, hill slope, stream side, 2000 m, 22 September 1992, Y. M. Shui 00160 ( KUN 233302) [2]; Yunnan Province:Wenshan County,Laojunshan Mountain Nature Reserve, evergreen forest, N23°16’39.8’’ E 103°57’42.7’’, 1840 m, 02 November 2017, D. M. He WSLJS1083 ( IBSC) [3]; Yunnan Province: Malipo, hill slope, 1800–2600 m, 26 May 1962, K. M. Feng 22889 (paratypes, IBSC: 0421082; KUN: 1208886, 1208887) [4]; Yunnan Province: Malipo County, Laojunshan Mountain, rocky hill, 24 April 1974, Anonymous s.n. ( KUN: 1208888) [5]; Yunnan Province: Malipo County, Laojunshan Mountain, hill slope, bushes, 23 April 2016, Y. H. Tong, X. E. Ye TYH-669 ( IBSC, 4 sheets) [6]; same location and date, Y. H. Tong, X. E. Ye TYH-670 ( IBSC, 2 sheets) [7]; same location and date, Y. H. Tong, X. E. Ye TYH-671 ( IBSC) [8]. VIETNAM. Lao Cai Province: Sa Pa District, near middle way go to Binh Lu, evergreen forest on high mountain, waysides, sunlight place, N 22°21’66.3’’ E 103°47’44.5’’, 1763 m, 14 September 2005, X. P. Vu, D. H. Duong, V.D. Nguyen, Q. B. Nguyen, T.X. Do, R. de Kok, G. Bramley, G. Challen, M. Vorontsova HNK 385 (HN, 3 sheets) [9]; Lao Cai Province: Sa Pa, 12 December 2004, N.Q. Binh, D.D. Cuong VN 1422 (HN: 0000022325, 0000022326) [10]; Cao Bang Province: Nguyen Binh district, Phia Oac-Phia Den National Park, 11 km WSW of Nguyen Binh town, Phia Oac summit area, disturbed wet foggy mossy crooked forest, N 22°36’58’’ E 105°51’46’’, elev. 1910 m, 03 October 2018, M. S. Nuraliev 2243 ( BRIT: BRIT 582224; IBSC; MW: MW 0757559 https://depo.msu.ru/open/public/en/item/ MW 0757559) [11]; Cao Bang Province: Nguyen Binh district, Nguyen Binh municipality, about 41 km to W of Cao Bang town, elevation from Le A pass to Na Ni mt. peak, old secondary closed evergreen wet mountain forest on soils developed on granite and shale rocks, N 22°37’ E 105°52’, 11–12 November 1998, L.V. Averyanov, N.Q. Binh, N. T. Hiep, P. K. Loc, N.X. Tam CBL 073 (HN: 0000021621; LE: LE01041980 http:// en.herbariumle.ru/?t=occ&id=1101; MO: not seen) [12]; Cao Bang Province: on the way from Phia Oac conservation state to the hill top, bushes, epilithic, 17 May 2018, N. H. Xia et al. TYH-1431 ( IBSC, 2 sheets) [13]; Cao Bang Province: Phia Oac-Phia Den National Park, edge of the road to the summit of Phia Oac, about 1 km from the summit, sedimentary limestone melange, N 22.613950° E 105.86678343°, elev. 1831 m, 07 November 2015, K. E. Hummer, T. T. T. Hoai , N.V. Kien, J. M. Oliphant VN-2015-073 (NA: NA-0103559) [14]; s.loc., s.d., N.V. Du 98 (HN, 3 sheets); s.loc., s.d., Phuong 8318 (HN, 3 sheets).

Ecology and phenology: —Forest and thickets on mountain slopes; 1600–2600 m. Flowering from July to October (December); fruiting from September to May.

Distribution: — China (SE Yunnan: Maguan, Malipo, Wenshan), Vietnam (Cao Bang: Phia Oac-Phia Den National Park, Lao Cai: Hoang Lien National Park) ( Fig. 5 ).

We observed this species to be common on the slopes and summit of Phia Oac Mountain at least from the elevation of 1600 m. We exclude the specimen K.E. Hummer et al. VN-2015-045 (NA: NA-0110338!) collected in Hoang Lien National Park and cited by Tran et al. (2016) and Hummer et al. (2017) from V. glaucorubrum . We tentatively identify it as V. hiepii Kloet in Vander Kloet & Paterson (2000: 582) based on its elliptic leaf blades with obtuse or rounded apices and punctate surfaces, sunken pinnate secondary veins and short racemes.

Figures

FIGURE 3. Vaccinium glaucorubrum. A. Branch with fruiting inflorescences. B. Leaf, abaxial surface. C. Raceme with flower buds. D. Flower, apical view. E. Fruit, apical view. F. Preanthetic stamen, dorsal view. G. Anthetic stamen, lateral view. H. Flower, lateral view. I. Flower, longitudinal section. J. Flower with perianth removed, lateral view. Photos by M. Nuraliev from Nuraliev 2243.

FIGURE 4. Vaccinium gaultheriifolium. A, B. Branches with anthetic inflorescences. C. Raceme with young fruits. D, E. Branches with fruiting inflorescences. F. Fruits, apical view. Photos: A, C by Y.H. Tong from Tong 11071502; B, E, F by Yong-Jie Guo taken in Dulongjiang (China); D by P.W. Fritsch from Lu et al. LL-2013-26.

FIGURE 5. Distribution map of Vaccinium gaultheriifolium and V. glaucorubrum. Numbers near locations refer to the collections cited in text; T refers to type collection.