Research Article |
Corresponding author: Yun-Hong Tan ( tyh@xtbg.org.cn ) Academic editor: Xiao-Hua Jin
© 2020 Hong-Bo Ding, Bin Yang, Mya Bhone Maw, Pyae Pyae Win, Yun-Hong Tan.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Ding H-B, Yang B, Maw MB, Win PP, Tan Y-H (2020) A new species and two new combinations of Monolophus (Zingiberaceae) from Indo-Burma. In: Jin X-H, Xia N-H, Tan Y-H (Eds) Plant diversity of Southeast Asia-II. PhytoKeys 138: 155-162. https://doi.org/10.3897/phytokeys.138.39217
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Monolophus odontochilus Y.H.Tan & H.B.Ding, a new species from Northern Myanmar, is described and illustrated. The new species is morphologically similar to M. linearis, but differs by having elliptic to oblong leaves (vs. linear-lanceolate to lanceolate), bilobed ligules (vs. entire), purely white corolla (vs. pinkish white), semi-orbicular crenate labellum (vs. trilobed). In addition, a diagnostic key to the new species of Monolophus and its closely related non-yellow flowered species is provided. New combinations are proposed here for Caulokaempferia phokhamii Picheans. & Douangde. and C. wongsuwaniae Picheans. & Douangde. from Laos.
Caulokaempferia phokhamii, Caulokaempferia wongsuwaniae, Kachin State, Putao District
The genus Monolophus was first described by
During our field work from May to June in 2018, some interesting specimens of Monolophus were found in Putao, Kachin state. Based on the detailed examination of the morphological characters of our material and morphologically similar species, we draw a conclusion that those specimens of Monolophus collected in Myanmar belong to a species new to science, Monolophus odontochilus Y.H.Tan & H.B.Ding, which is described here along with illustrations.
Measurements and morphological character assessments of the new species have been examined based on fresh materials and dried specimens. It has been compared with the morphologically similar species by affinities inferred using descriptions (
Monolophus odontochilus is morphologically similar to M. linearis (Wall.) Wall. from India in having white flowers with yellow blotch at the base of the labellum, but differs by having elliptic to oblong leaves (vs. linear-lanceolate to lanceolate leaves), bilobed ligules (vs. entire ligules), semi-orbicular crenate labellum (vs. trilobed labellum) and purely white corolla (vs. pinkish white corolla).
Myanmar. Kachin State: Putao District, Gathu Village. 27°29'07.23"N, 97°58'19.49"E, 643 m, 01 June 2018, Y.H.Tan, B.Yang, H.B.Ding, X.D.Zeng, M.B.Maw and H.L.Neing M3886 (holotype: HITBC!, isotypes: RAF!).
Perennial herbs, rhizome short; pseudostem erect, leafy 50–70 cm long. Leaves 5–13, sub-sessile, elliptic to oblong, 10.2–14 × 3.0–5.0 cm, base cuneate, apex caudate to 2.0 cm long, margins entire, adaxial surface dark green, glabrous, abaxially light green, pubescent; ligule membranous, 6–8 mm long, hairy, apex unequally bilobed. Inflorescences terminal, 5–7 cm long, rachis glabrous; flowers white with yellow blotch at the base of the labellum; bracts 4–6, along rachis, distichous, oblong, 3.5–4.0 × 1.0–1.3 cm, greenish, outer surface pubescent, base truncate, apex cuspidate to 0.8 cm, 2-flowered; bracteoles membranous, lanceolate, ca. 1.5 × 0.8 cm, pubescent, rounded; calyx tubular, 1.3–1.4 × 0.3–0.4 cm, pubescent, greenish, split 6–7 mm down one side, apex acute; floral tube 4.3–4.5 cm, ca. 3.5 mm wide at mouth, white, glabrous; dorsal corolla lobe lanceolate, 2.2–2.3 × 0.6–0.7 cm, white, glabrous, hooded at apex, apical cusp ca. 2 mm long; lateral corolla lobes similar to dorsal lobe, narrower, 2.0–2.1 × 0.3–0.4 cm, hooded at apex, apical cusp ca. 1 mm long; lateral staminodes elliptic, 1.5–1.6 × 0.9–1.0 cm, white, apex rounded; labellum semi-orbicular, 4.4–4.8 × 3.2–3.6 cm, white with yellow spot at base, margin crenate; anther 4–5 mm long; anther crest flabellate, 2–3 × 4–5 mm, white, apex entire; stigma funnel-shaped, inserted between anther sac, margin raised on both ends, ciliate; ovary oblong, 3–4 mm long, pubescent, 3-locular.
Monolophus odontochilus Y.H. Tan & H.B. Ding, sp. nov. A habitat B ligule C leaf blade abaxially D habit E single leaf (adaxially and abaxially) F flower (side view) G flower (front view) H anther with stigma and crest (front and back view) I stigma J dorsal corolla lobe K lateral corolla lobes L bracts M bracteoles and young flower N calyx O ovary P labellum and floral tube Q lateral staminodes R stamen and stigma S ovary with style. Photographed by H.B.Ding
Flowering in May to June. Fruit not seen.
The species epithet ‘odontochilus’ refers to the crenate labellum.
Monolophus odontochilus is endemic to Kachin State, Northern Myanmar, only known from its type locality, Gathu Village, Putao District. It grows in humid environments or along streams of tropical rain forest at an elevation of 550–750 m.
This new species appears to be restricted to a very moist habitat in Gathu Village, Putao District, Kachin State, Northern Myanmar. According to our observations in the field, the two known populations are composed of about 50 mature individuals in each. Overall, however, the species has been deemed to be Data Deficient (DD) following IUCN Red list Categories and Criteria (
Monolophus odontochilus is morphologically similar to M. linearis (Wall.) Wall. (
1 | Flowers completely pink | 2 |
– | Flowers usually white, if corolla and lateral staminodes pink then labellum white | 3 |
2 | All leaves sessile, blade to 2.8 cm broad, ligule absent or indistinct | M. suksathanii |
– | At least upper leaves petiolate, blade 2.5–4 cm broad, ligule distinct | M. secundus |
3 | Labellum completely white, without yellow blotch | M. sikkimensis |
– | Labellum white with yellow blotch | 4 |
4 | Corolla completely white | M. odontochilus |
– | Corolla pink to purple-pink | 5 |
5 | Leaf blades linear-lanceolate to lanceolate, labellum trilobed | M. linearis |
– | Leaf blades oblong to oblong-elliptic, labellum entire | M. arunachalensis |
Caulokaempferia phokhamii Picheans. & Douangde. in Douangdeuane et al., Pak. J. Bot. 51(1): 235. 2019.
Lao PDR. Vientiane Province, Hin Herb District, Phou Meut-Phou Kiykon Forest Conservation, Ban Hoiuy Dokmai (Hoiuy Dokmai Waterfall), 18°42'58.20"N, 102°22'20.94"E, 270 m, 26 August 2014, CP260814-1 (holotype: BK, isotypes: MSU).
Caulokaempferia wongsuwaniae Picheans. & Douangde. in Douangdeuane et al., Pak. J. Bot. 51(1): 237. 2019.
Lao PDR. Bolikhamxai Province, Mueang Tha Pabad District, Nam Tok Tad Mangkorn, 18°25'59.82"N, 103°12'32.64"E, 200 m, 20 September 2014, CP200914-1 (holotype: BK, isotypes: MSU).
The authors are grateful to the Forest Research Institute of Myanmar for permission to conduct this study in the Northern Myanmar, and for their support and collaboration. We are grateful to Xiao-Dong Zeng, Kyaw Saw and Myint Zaw for their kind help in the fieldwork. This work was financially supported by a grant from National Natural Science Foundation of China (Grant no. 31970223) awarded to Yun-Hong Tan, by a project of the Lancang-Mekong Cooperation (LMC) Special Fund (Biodiversity Monitoring and Network Construction along Lancang-Mekong River Basin project), by the Southeast Asia biodiversity research institute, Chinese Academy of Sciences (Y4ZK111B01) and the CAS 135 program (No. 2017XTBG-F03).