Gaultheria natmataungensis P.W.Fritsch, 2023

Fritsch, Peter W., Armstrong, Kate E., Aung, Mu Mu, Fujikawa, Kazumi & Lu, Lu, 2023, Gaultheria (Ericaceae) of Myanmar: an updated species list for the country, a new species, and a new species combination, Phytotaxa 595 (1), pp. 37-61 : 47-50

15. Gaultheria natmataungensis P.W.Fritsch , sp. nov.

Type:— MYANMAR. Chin: [Mindat District, Kanpetlet Township ,] 5–6 miles from the entrance of Natma Taung National Park , between Kampetlet [Kanpetlet] and 10 miles base camp of national park, Natma Taung National Park , 2,400 m, 20°12’48.9”N, 93°59’29.6”E, 5 December 2012 (fl), K. Fujikawa, K. Miyake, M.M. Aung, K. Yabe, M. Hlaing, L.S. Man & L. Shine 090559 (holotype BRIT BRIT713359 !, isotype MBK No. 0246774 !).

Diagnosis— This new species resembles Gaultheria discolor but differs by its longer petioles with slightly winged margin, adaxially glandular-punctate or setulose leaves adaxially, smaller narrowly deltoid bracts, and smaller bracteoles that are borne medially on pedicels.

Description— Shrubs or trees 0.3–2.0 m tall, erect. Branchlets ± straight, when young brown in sicco, red in vivo, when older dark gray, rounded, with dark red to black straight- to uncinate-ascending setae from nearly globose to 0.6 mm long, occasionally also patchily white-puberulous; overwintering floral buds not seen (absent?). Leaves: petioles 8–22 × (medially) 1.0– 2.5 mm, setulose, slightly winged throughout by decurrent leaf blade base, abaxially rounded, adaxially caniculate, adaxially white-puberulous towards base and along furrow; blades broadly elliptic to slightly ovate, 5.0–10.7 × 3.0– 5.4 mm, 1.2–2.2 times as long as wide, subcoriaceous, abaxially greenish brown to pale or whitish brown in sicco, whitish green in vivo, adaxially light green to grayish green or light brown in sicco, bright green to deeply flushed red in vivo, dark red- to black-glandular punctate- or usually appressed to ascendingsetulose on both sides, more densely so abaxially, with setae persistent, up to 0.40 mm long, adaxially puberulous on midvein toward base or ± throughout and often on secondary veins, midvein abaxially prominent, adaxially caniculate, secondary veins 3 to 6 on each side of midvein, arc-ascending, not extending to margin, abaxially raised, adaxially slightly raised to slightly impressed, tertiary veins raised or planar on both sides, base broadly cuneate or rarely subrounded, decurrent into petiole, margin serrulate with 15 to 20 setulose teeth per side, teeth more prominent toward apex, often reduced to punctae proximally, revolute, apex obtuse, bluntly glandular-mucronate, mucro 0.8–2.0 mm long. Inflorescences of axillary and pseudoterminal racemes (pseudoterminal inflorescences occasionally with 2 branches or rarely 7 branches) mainly from distal leaf axils along branchlet, 1 to 3 per leaf axil or up to 7 scattered along branchlet end, 3–4 cm long, 6- to 19-flowered, erect but flowers pendulous; peduncle and rachis 0.6–0.8 mm wide, slightly angled, setulose, occasionally white-puberulous; perules persistent, similar to bracts; bracts narrowly deltoid, cucullate, keeled, 1.3–2.3 × 0.8–1.5 mm, occasionally longer toward inflorescence base, abaxially glabrous or occasionally glandular-punctate, adaxially white-puberulous, margin ciliolate and often globose- to elongate-glandular, apex sharply acute. Pedicels 2.5–6 mm long, setulose or rarely glabrous below bracteoles and puberulous above bracteoles; bracteoles borne medially, narrowly deltoid, cucullate, not keeled, 1.2–2 × 0.7–1.3 mm, abaxially glabrous, adaxially white-puberulous, margin often ciliolate, often globose- to elongate-glandular, apex sharply acute. Calyx 1.9–3.5 mm long, tube broadly funnelform to cupuliform, white-puberulent especially toward base, trichomes up to 0.2 mm long, lobes 5, green to white or slightly flushed red, narrowly deltoid to deltoid-ovate, 1.6–2.6 × 1.0– 1.2 mm, outside sparsely puberulous, inside sericeous-puberulous, margin elongate-glandular and usually white-ciliolate, apex sharply acute. Corolla white or pinkish white, urceolate, 4.0–5.6 × 2.2–3.9 mm, outside glabrous or occasionally puberulous, inside white-hirtellous with trichomes up to 0.4 mm long; lobes 5, hemispherical, 0.8–1.1 × 0.7–1.2 mm. Stamens 10; filaments ca. 1.5 mm long, dilated submedially, papillate-puberulent; anther cells 0.8–1.2 mm long, awns 2 per theca, 0.2–0.6 mm long. Nectar disk 10-dentate. Ovary white-hirtellous, trichomes up to 0.4 mm long; style 2.5– 4.0 mm long, glabrous. Infructescences 3.5–8.3 cm long. Fruiting pedicels 4–8 mm long. Fruiting calyx in vivo blue to dark purple, occasionally glaucous, in sicco nigrescent, occasionally glaucous, slightly wrinkled, obturbinate, closed, 3.6–7.5 × 4.5–6.5 mm, fleshy; lobes ovate, 3.5–4.0 × 3.0– 3.5 mm, glabrous, margin not ciliolate, apex acuminate, in vivo fleshy and incurved, covering capsule, in sicco thin and spreading, not completely covering capsule. Capsule depressed-globose, 3.5–5.0 mm diam., white-sericeous. Seeds brown.

Classification — Gaultheria sect. Brossaea ser. Leucothoide s.

Phylogenetic placement — Leucothoides s.l. clade.

Images — Figure 3 .

Illustration — Figure 4 .

Phenology —flowering February, August, November, December; fruiting May.

Habitat, elevation range, and distribution —Evergreen forest, pine forest, meadow in forest gap, dry ridge, forest edge, roadside, open or semi-shaded with scattered Rhododendron Linnaeus 1753: 392 ) and Lyonia Nuttall (1818: 266) ; 1,829 – 2,710 m elevation. Endemic to Myanmar (Chin [Mindat District]); Figure 5 .

Additional specimens examined (paratypes) — MYANMAR. Chin: Mindat District, Kanpetlet Township. [Natma Taung National Park,] Mt. Victoria, 3 miles below, 27 May 1924 (fr), R.E. Cooper 5979A (E E00197148!); between Kanpetlet and 10 miles base camp of Natma Taung ( Mt. Victoria ), Natma Taung National Park , 2,220 m, 21°12’49.6”N, 94°00’50.7”E, 11 February 2012 (fl), K. Fujikawa et al. 086544 (MBK No. 0239732!); around 10 miles base camp of Natma Taung ( Mt. Victoria ), Natma Taung National Park , 2,710 m, 21°13’08.0”N, 93°56’23.8”E, 12 February 2012 (fl, young fr), K. Fujikawa et al. 086581 (MBK No. 0239743!); ca. 37 miles ( Mindat–Matupi road) from Mindat , Mindat Township , Natma Taung National Park , 2,460 m, 21°33’59.0”N, 93°48’00.3”E, 26 May 2012 (fr), K. Fujikawa et al. 089310 (MBK No. 0243050!); ca. 4–8 miles from entrance of national park, between Kanpetlet and 10 miles base camp of Natma Taung ( Mt. Victoria ), Natma Taung National Park , 2,220–2,600 m, 21°12’19.6”N, 94°01’31.6”E, 29 May 2012 (fr), K. Fujikawa et al. 089541 (BRIT BRIT713360!, MBK No. 0246484!); 37 miles from Mindat , between Mindat and Matupi ( Mindat–Matupi Road), Mindat Township , Natma Taung National Park , 2,450–2,545 m, 21°33’58.3”N, 93°48’01.5”E, 31 August 2013 (fl), K. Fujikawa et al. 094743 (BRIT BRIT713361!, MBK No. 0255051!); [Natma Taung National Park,] Mt. Victoria , Kanpetlet Road, 8,000 ft, 5 November 1956 (fl), F. Kingdon-Ward 22826 (BM BM013823055!*); [Natma Taung National Park,] Mt. Victoria , 7,000 ft, 16 April 1925 (young fr), R. Unwin 3048 (E E00887328!*).

Possible additional specimen — Chin: [Mindat District, Kanpetlet Township,] Natma Taung National Park area near Kampetlet-Mindat Road on laurel forest edges, 2,560 m, 21°13’14”N, 93°57’35”E, 3 February 2014, Ling S.M. SM-41 (HHU n.v.; as Gaultheria longibracteolata in Kang et al. 2017). This specimen is listed as G. longibracteolata (= G. discolor ) in Kang et al. 2017 but may be G. natmataungensis as judged from its locality.

Conservation assessment— In the absence of definitive information, we recommend the category “Data Deficient” (DD) for Gaultheria natmataungensis in accordance with the International Union for Conservation of Nature Red List criteria ( IUCN Standards and Petitions Subcommittee 2022). It grows within the protected area of Natma Taung National Park but has a risk of habitat loss from road expansion. The number of individuals and populations located in the park has not been assessed.

Discussion —In the process of compiling this checklist, we encountered digital images of specimens collected by R.E. Cooper, F. Kingdon-Ward, and R. Unwin from Mt. Natma Taung (Mt. Victoria) that appeared to differ from the known species of Gaultheria . The new species status of these specimens was confirmed by examination of recent material collected by authors Fujikawa and Aung from Mt. Natma Taung in Natma Taung National Park and a review of the relevant literature ( Sleumer 1967, Airy Shaw 1941, Fang & Stevens 2005, Fritsch et al. 2008, Watthana 2015, Panda 2015). The species is described above as Gaultheria natmataungensis , with the specific epithet referring to its occurrence on Mt. Natma Taung. It is the only known species of Gaultheria that is endemic to Myanmar.

Gaultheria natmataungensis is assignable to Gaultheria sect. Brossaea D.J.Middleton ser. Leucothoides D.J.Middleton by leaf blade secondary veins pinnate, inflorescences of true racemes of> 4 flowers with perules, bracts <6 mm long, bracteoles borne medially along the pedicel, corolla urceolate, anthers without tubules and with awns, fruit a capsule surrounded by a fleshy accrescent calyx, racemes perulate, and geographic distribution in eastern Asia ( Middleton 1991). As based on these features, it can be expected to group within the Leucothoides s.l. clade of Lu et al. (2019a). It is unique within this series by the combination of setose branchlets, slightly winged petioles 8–22 mm long, leaf blades 5.0–10.7 × 3.0– 5.4 mm and glandular-punctate to setulose on both sides with broadly cuneate or rarely subrounded base, inflorescence peduncles and rachises setulose, bracts 1.4–2.3 × 0.8–1.5 mm, flowers strictly 5-merous, pedicels 2.5–6 mm long, bracteoles borne medially along pedicel, calyx outside white-puberulous, corollas urceolate, and stamens 10.

See also Appendix Notes 3, 4 and 6.

Figures

FIGURE 3. Gaultheria natmataungensis. A. Flowering branchlets. B. Fruiting branchlets. C. Leaves and inflorescence. Photographs by KF.

FIGURE 4. Gaultheria natmataungensis. A. Flowering branchlet. B. Leaf, abaxial view. C. Petiole with adjacent branchlet and base of leaf blade, showing short setae. D. Flower. E. Gynoecium and nectary disk. F. Stamen, ventral view. G. Stamen, lateral view. H. Immature fruiting calyx and capsule, showing bracetoles. I. Mature fruiting calyx and capsule (bracteoles not shown). A–D based on K. Fujikawa et al. 090559 (BRIT); E–G based on K. Fujikawa et al. 086581 (MBK); H, I based on K. Fujikawa et al. 089541 (BRIT). Illustration by Samantha Peters.

FIGURE 5. Geographic distribution of Gaultheria natmataungensis.