Gaultheria obovata (Airy Shaw) P.W.Fritsch & Lu Lu, 2015

Fritsch, Peter W., Lu, Lu, Wang, Hong & Li, De-Zhu, 2015, New species, taxonomic renovations, and typifications in Gaultheria series Trichophyllae (Ericaceae), Phytotaxa 201 (1), pp. 1-26 : 17-18

6. Gaultheria obovata (Airy Shaw) P.W.Fritsch & Lu Lu , comb. et stat. nov.

≡ Gaultheria trichophylla Royle (1835: 260) var. obovata Airy Shaw (1941: 324) . Type:— MYANMAR. Kachin: Upper Burma [Myitkyina District], [Waingmaw Township], Seinghku Wang, 11,000 ft, 28°08 ʹ N, 97°24 ʹ E, 17 June 1926, F. Kingdon Ward 6944 (holotype K!).

Prostrate-ascending shrublet with stems to 8 cm long from horizontal stolons, hermaphroditic. Current-year branchlets pale green, strongly flushed red, occasionally brown proximally, to 4 cm long, with sparse white puberulence and appressed to nearly erect straight or slightly undulate setae, longer setae 0.7–1.2 mm long. Internodes among largest leaves averaging ca. 1.7–3.2 mm. Petioles 0.6–1.3 mm long, abaxially glabrous or with sparse ascending to nearly erect setae abaxially, adaxially with sparse white puberulence in a line, margin entire. Longer leaf blades broadly elliptic to slightly obovate, 6.2–12 × 3.5–6.2 mm, 1.4–2.2 times as long as wide, subcoriaceous, planar, abaxially dull whitish green except glossy and occasionally flushed maroon near margin, at least some leaves with 1 to 9 (to 22) ascending to nearly erect setae scattered on midvein or rarely also on surface but near midvein (longer setae 0.64–1.1 mm long), adaxially glossy deep green, midvein abaxially raised, not thickened immediately below apical gland, adaxially impressed and with white puberulence proximally, secondary veins 1 to 4 on each side of midvein, faint, adaxially impressed; base broadly cuneate to subrounded; margin serrulate except toward very base, planar or slightly revolute, marginal teeth (setae) 8 to 14 per side, all teeth oriented off leaf surface, longer teeth 0.7–1.3 mm long; apex obtuse to rounded, tip with planar apical gland. Overwintering flower bud pedicels 1.7–3.8 mm, glabrous; overwintering flower buds slightly compressed to subglobose laterally, 1–2.1 × 0.8–2 mm, 0.9–1.3 times as long as wide, glabrous, bracteoles not keeled, margins eciliolate. Flowers ca. 5 mm long. Calyx green proximally with lobes green flushed pale pink, 2.7–4.2 mm long; lobes broadly deltoid, 1.2–2 × 1.4–2.1 mm, adaxially glabrous, apex obtuse, eciliolate, erose. Corolla white, campanulate, 3–4 × 3–5.3 mm; lobes 0.9–2.4 × 0.9–2 mm. Stamens 10; filaments dilated gradually then constricted gradually toward middle, 0.8–1 mm long; anther cells 0.4–0.6 mm long, awns 2 per theca, 0.1–0.3 mm long. Style 1–1.7 mm long; stigma pink. Fruiting pedicel 2–4.1 mm long. Fruiting calyx oblate, crateriform to cupuliform, widely open, 4.5–10 × 6–12 mm, outer wall deep sky blue, inner wall white; calyx lobes erect to slightly incurved, broadly deltoid, 2.8–5 mm long, apex eciliolate, slightly erose. Capsule green, exceeded by calyx lobes.

Illustration — Figure 9 .

Images — Figure 6K–N .

Phenology —Flowering June; fruiting July–September.

Habitat and distribution — Coniferous forest , alpine thickets and meadows, in humus and moss among rocks, marble and metamorphics ; 3200–4484 m elev. China (Yunnan, Xizang), Myanmar (Kachin) .

Discussion — Airy Shaw (1941) described this taxon as a variety of Gaultheria trichophylla , apparently because it shares with G. trichophylla the presence of notably long stem and leaf marginal setae (ca. 0.7–1.3 mm long). The number of morphological character differences between these taxa, however, is more than sufficient to justify the recognition of this variety as a species. Gaultheria obovata differs from G. trichophylla most consistently in its longer overwintering flower bud pedicels (1.7–3.8 mm versus 0.6–1.2 mm) and shorter calyx lobes (1.2–2 mm versus 2–3 mm). It also has generally larger leaf blades (6.2–12 × 3.5–6.2 mm versus 3.7–8.5 × 2.5–3.5 mm) with more marginal teeth (8 to 14 per side versus 6 to 12 per side), subglobose overwintering flower buds (versus slightly compressed laterally), and an open (versus usually closed) fruiting calyx. Samples of the two species are recovered as widely separated phylogenetically in the molecular study of Lu et al. (2010). In that study, the samples L. Lu 06-0007 and 06-0019, designated as G. trichophylla 4F and 2L, respectively, were found to group with each other but well apart from the clade formed by the samples L. Lu 07155, 07308, and 07400, designated as G. trichophylla 5B, 1C, and 3G, respectively. The first two samples are here identified as G. trichophylla , as in Lu et al. (2010), and the latter three as G. obovata .

Additional specimens examined — CHINA. Yunnan: Deqin Xian. Meili Snow Mtns., Yubeng Village, trail to Dabenying, 3600–3800 m, August 2007, L. Lu LL-07400 (CAS!); E slope of Meili Xue Shan, just below 1991 Sino- Japanese Base Camp at river, W of Upper Yubeng Village, 3563 m, N28.39948°, E98.76363°, 10 September 2011, L. Lu & P.W. Fritsch LL-2011-21 (CAS!, GH!); Melixueshan (Meili Snow Mtns.), foot trail from Yubeng Village to Xiaonong (sacred meadow), W of Xiaonong, 3800–3900 m, 28°23 ʹ 56 ʺ N, 98°45 ʹ 09 ʺ E, 23 July 2001, H.H. Schmidt et al. 4097 (CAS!); Tehching (Atuntze), Miyetzimu, 3200 m, 22 June 1937, T.T. Yü 8702 (KUN!); Zhashibugong, 4100 m, 6 November 1937, T.T. Yü 10642 (KUN [2]!). Gongshan Dulongzu Nuzu Zizhixian. Bangdang Xiang, Biluo Xue Shan, Balagong spur, trail from Dimaluo to Balagong Pass, 3599 m, 27°57 ʹ 49.8 ʺ N, 98°44 ʹ 26.4 ʺ E, 23 September 2013, L. Lu LL-2013-41 (CAS!, GH!, KUN!); Bangdang Township, Biluo Xue Shan, vicinity of Sila Pass, 3912 m, 27°59 ʹ 46.0 ʺ N, 98°47 ʹ 23.4 ʺ E, 24 September 2013, L. Lu LL-2013-49 (CAS!, GH!, KUN!); Upper Kiukiang Valley, (Clulung) Chialahmuto, 3600–4000 m, 7 August 1938, T.T. Yü 19732 (A!, E!, KUN!). Xizang: Chayu Xian. Linzhi Prefecture, rd from Bomê to Mêdog, Galongla Pass, 4280 m, 29°45 ʹ 22 ʺ N, 95°42 ʹ 18 ʺ E, 25 September 2009, H. Sun et al. SunH-07ZX-2664 p.p. (KUN! mixed with G. eciliata and G. cf. sinensis ). Gongbujiangda Xian. Nambu La, 14,800 ft, 24 September 1947, F. Ludlow et al. 15775 (E!). Motuo Xian. Duoxiongla, trail to Lage, 3500–3700 m, 29°29 ʹ N, 94°55 ʹ E, 24 July 2007, L. Lu LL-07155 (CAS!); Pailong Village, trail from Linzhi to Pailong, 3700 m, 7 August 2007, L. Lu LL-07308 (CAS!). Zuogong Xian. Pi-tu La, 14,000 –15,000 ft, 7 September 1922, F. Kingdon Ward 5389 (E!). MYANMAR. Kachin: Putao District. Nogmung Township, Adung Valley, 12000–13000 ft, 15 June 1931, F. Kingdon Ward 9639 p.p. [A; mixed with G. thymifolia Stapf ex Airy Shaw (1941: 322) ].

Figures

FIGURE 6. Images of Gaultheria eciliata, G. major, and G. obovata. A–E. Gaultheria eciliata, habit (A), flower lateral view (B) and apical view (C), fruit lateral view (D) and apical view (E) (A: L. Lu LL-2013-32; B–C: L. Lu LL-2014-3; D–E: L. Lu LL-2013-21). F–J. Gaultheria major, habit (F), flower bud and flower, lateral view (G), flower, apical view (H), fruit, lateral view (I) and apical view (J) (F: L. Lu LL-2013-37; G–H: L. Lu LL-2013-51; I–J: L. Lu LL-2013-40). K–N. Gaultheria obovata, habit (K), flower, apical view (L), fruit, lateral view (M) and apical view (N) (K–L: L. Lu & P.W. Fritsch LL-2011-21; M–N: L. Lu LL-2013-41). Photographs:A–B, D–H by PWF; C, I–N by LL. Scale bars: A, F, K, 10 cm; B–C, 3 mm; D–E, I–J, M–N, 10 mm; G–H, L, 5 mm.

FIGURE 9. Gaultheria obovata. A. Flowering plant. B. Section of branchlet with leaf in abaxial view. C. Section of branchlet with leaf bases in abaxial (right) and adaxial (left) view, and flower buds. D. Flower. E. Stamen. F. Nectar glands and gynoecium. G. Fruit, lateral view. H. Fruit, apical view. (A–B, D drawn from the holotype, F. Kingdon Ward 6944, K; C drawn from L. Lu LL-2013-49, CAS; E drawn from L. Lu LL-07308, CAS; F drawn from L. Lu LL-07155, CAS; G–H drawn from L. Lu & P.W. Fritsch LL-2011-21, CAS, and images of the living plant.)