Research Article |
Corresponding author: Yun-Hong Tan ( tyh@xtbg.org.cn ) Academic editor: Xiao-Hua Jin
© 2018 Bin Yang, Hong-Bo Ding, Shi-Shun Zhou, Xinxin Zhu, Ren Li, Mya Bhone Maw, 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:
Yang B, Ding H-B, Zhou S-S, Zhu X, Li R, Maw MB, Tan Y-H (2018) Aristolochia sinoburmanica (Aristolochiaceae), a new species from north Myanmar. In: Jin X-H, Shui Y-M, Tan Y-H, Kang M (Eds) Plant diversity in Southeast Asia. PhytoKeys 94: 13-22. https://doi.org/10.3897/phytokeys.94.21557
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Aristolochia sinoburmanica Y.H.Tan & B.Yang, a new species of Aristolochiaceae from Putao, Kachin State, Myanmar, is described and illustrated. According to morphology (strongly curved perianth, 3-lobed limb, as well as 3-lobed gynostemium, anthers 6, adnate in 3 pairs to the base of gynostemium, opposite to the lobes), the species belongs to Aristolochia subgenus Siphisia. It is morphologically similar to A. faviogonzalezii, A. hainanensis, A. tonkinensis, A. saccata and A. xuanlienensis. The major differences between them are outlined and discussed. A detailed description, along with line drawings, photographs, habitat, distribution and conservation status, as well as a comparison to morphologically similar species, are also provided.
Kachin state, Aristolochia , Aristolochiaceae , field expedition, Myanmar
Aristolochia L., with about 550 recognised species (
During a field expedition to Putao, Kachin state, north Myanmar, an unknown species of Aristolochia was collected. After careful studies of the genus, particularly the floral characteristics of those species in the adjacent regions, as well as comparison between this unknown species and its related species, it is confirmed as a new species of Aristolochia which has strongly curved perianth, 3-lobed limb, as well as 3-lobed gynostemium and should be assigned to the subgenus Siphisia. The new species presented here was also collected by a famous Chinese botanist, Professor K. M. Feng in 1959 (KUN, No. 0163232) from northwest Yunnan, China. The specimen consists of four leaves, being complemented by good field notes and was identified as Aristolochia hainanensis. In this paper, this new Aristolochia species is described and illustrated.
Measurements and morphological character assessments of the possible new species Aristolochia sinoburmanica were made from both dried specimens and field observations of living plants which allowed comparison of morphological characters and colouration of the perianth (utricle, tube and limb) as well as morphology of the inside of the trap flowers, including the gynostemium, which are often impossible to observe in dried specimens. The description of the new species follows the terminology used by
The data underpinning the analyses reported in this paper are deposited in the Dryad Data Repository at https://doi.org/10.5061/dryad.2501p.
Aristolochia sinoburmanica is morphologically similar to A. hainanensis Merrill, A. saccata Wallich, A. xuanlienensis (
Morphological comparison of key characters and distribution in A. sinoburmanica and its similar taxa.
Character | A. sinoburmanica | A. faviogonzalezii | A. hainanensis | A. tonkinensis | A. saccata | A. xuanlienensis |
---|---|---|---|---|---|---|
Leaf blade | ovate or ovate-lanceolate to narrowly ovate | broadly ovate to cordate | ovate to ovate-lanceolate | ovate to broadly-ovate | ovate-oblong to ovate-lanceolate | ovate or lanceolate-ovate to narrowly ovate |
Leaf base | rounded to slightly cordate | slightly to deeply cordate | cuneate to rounded | rounded to truncate | cordate | rounded |
Inflorescence | cyme solitary on old woody stems and young branches, each cyme with1–2 flowers | cluster of 6–8(-10) cymes at each node on old woody stem, each cyme with 3–4 flowers | cyme in axils of leafy shoots or on old woody stems, with 3–6 flowers | cyme solitary on old woody stems and young branches with 3–4 flowers | cluster of 2–3 cymes at each node on old woody stems, each cyme with 3–5 flowers | cyme usually in axils of leafy shoots or on old woody stems, 3–4(-5) flowers |
Perianth | claret (deep purple red), outside densely brown hirsute with parallel dark purple veins, 6.5–7.5 cm high | yellowish-white with parallel dark purple veins or dots, 3.5–5 cm high | yellowish with obscure purplish veins | outside white, densely villous with parallel purple veins, 3.2–3.5 cm high | white with purple reticulate veins | white with light purple veins outside and dark purple spots, 4.5–4.8 cm high |
Limb | discoid-rotund or trumpet-shaped , 4.2–4.8 cm high, 4–4.4 cm wide, 3-lobed, lobes subequal, dark purple, densely covered with dark purple warts | trumpet-shaped, nearly rectangular, 2.4–2.6 cm high, 1.8–2 cm wide, 3-lobed, lobes unequal, dark purple, warty on inner surface | obliquely trumpet-shaped, nearly circular, 2.2–2.5 cm wide, 3-lobed, lobes unequal, purple, densely dark purple warts | trumpet-shaped, nearly rectangular, 1.2–1.3 cm high, 0.9–1.0 cm wide, 3-lobed, lobes unequal, dark purple, densely covered with dark purple bristles | obliquely trumpet-shaped, nearly circular, 1.8–2 cm wide, 3-lobed, lobes unequal, upper 2 distinctly recurved, deltoid, lower one broadly deltoid, covered with purple warts | trumpet-shaped, ca. 2.5 cm wide, 3-lobed , lobes subequal , fused with margins of all lobes strongly revolute, densely covered with purple papillate |
Throat | deep purple red, glabrous | upper half white with dark purple dots and lower half pinkish without visible dots | yellow, without visible dots | white, without visible dots | yellow, without visible dots | white, densely covered with purple dots |
Distribution | China, Myanmar | Vietnam | China, Vietnam | Vietnam | China, Bhutan, NE India, Myanmar, Nepal | Southern Vietnam |
MYANMAR. Kachin State: Putao, near Shinshanku, on the roadside slope of a mountain range bordering the zone of Hkakaborazi National Park, perennial lianas under tropical mountain broadleaf forest, 27°38'48.65"N, 97°54'01.61"E, 900 m a.s.l., 11 May 2017, Myanmar Exped. 1532 (holotype HITBC!).
Perennial woody liana, 8–12 m high. Stem terete, circular in cross section, ca. 1 cm in diam., young branches green, sparsely pubescent, becoming glabrescent, bark deeply irregularly longitudinally fissured when mature, internodes 7–15 cm long. Petiole 3.5–6.0 cm long, twisted, pubescent. Leaf blade ovate or ovate-lanceolate to narrowly ovate, subcoriaceous, 15–31.5 × 5.8–12.5 cm, base rounded to slightly cordate, apex acuminate, margin entire, both surfaces densely villous when young, then the adaxial surface dark-green and glabrous, the abaxial surface densely villous; basal veins five, palmate, secondary veins four to six pairs, pinnate; tertiary veins coarsely reticulate, slightly sunken adaxially, prominent abaxially. Inflorescence cymose on old woody stems and young branches, solitary or two cymes, each cyme with one or two flowers, clearly separated from each other. Inflorescence axis 2–6 mm long, tomentose. Bracteole clasping the axis, ovate-triangular, 2–4.5 × 1.5–2 mm, subsessile, both surfaces densely brown villous. Pedicel 1.3–1.6 cm long, pendulous, densely brown villous. Ovary oblong, 1.5–1.7 × 0.3–0.4 cm, densely brown villous. Perianth horseshoe-shaped (in lateral view), 6.5–7.5 cm high, claret (deep purple red), outside densely brown hirsute with parallel dark purple veins, inside glabrous to white villous. Utricle distinct from the tube, bell-shaped, 2.3–2.5 cm high, 1.2–1.3 cm in diam. at base, 1.6–1.8 cm in diam. at apex, inside vinaceous (purplish red) with densely white trichomes. Tube horseshoe-shaped, 8.3–8.5 cm, uniformly claret (deep purple red), with visible dark purple veins, lower tube strongly inflated, saccate, 2.5–2.7 cm high, 1.8–2.0 cm in diam. and upper tube obliquely shortened funnel-shaped, parallel to the utricle, inner surface stramineous dyed with purple red patches, 3–3.5 cm high, narrower at base, 1–1.1 cm in diam. and broader at apex, 1.3–1.4 cm in diam. Limb discoid-rotund or trumpet-shaped, 4.2–4.8 cm high, 4–4.4 cm wide, with three subequal lobes, valvate preanthesis, lobes broadly ovate-triangular, each 3.3–3.8 cm wide, 1.8–2.2 cm high, margins of all lobes revolute during anthesis, warty on inner surface of lobes dark purple. Throat deep purple red, glabrous, without dots. Annulus present. Gynostemium with trilobed stigma on top, 7–7.5 × 5.5–6.5 mm in diam., anthers 6 in 3 pairs, oblong, 4.3–4.5 × 1.2–1.4 mm, yellow. Fruit and seeds were not seen.
Flowering specimens have been collected in May but it is possible that flowering begins in April and fruiting may be from July to August.
The species epithet refers to the type locality in Myanmar and adjacent regions of China. It also shows that the two countries are friendly neighbours, their friendship being retained over a long period and also expresses our appreciation for the whole-hearted cooperation amongst members of the China-Myanmar joint expedition.
Aristolochia sinoburmanica is hitherto known from the type locality of Putao, Kachin state in north Myanmar and adjacent regions of Gongshan County, northwest Yunnan, southwest China, where, according to one sheet of the specimen deposited in KUN, it is a perennial liana which grows under the montane broadleaf forests, at an elevation of ca. 900–1400 m.
In Nov. 2014, the China-Myanmar joint expedition conducted the first field investigation of plant diversity along the same route in north Myanmar, within the area which included the type locality of this new species. The path through the mountains could only be accessed by foot, but in the most recent expedition in May 2017, with the development of road construction, most of the trees and habitats have been destroyed. A. sinoburmanica is known from a single population on the roadside. In fact, during the present study, only two healthy individuals were located growing about 20m apart from each other. Therefore, the new species is assigned a preliminary status of vulnerable (VU) according to the IUCN Red List Categories (
Aristolochia sinoburmanica Y.H.Tan & B.Yang, sp. nov. A young branch and adaxial leaf B young branch and abaxial leaf C cymes on old woody stems D front view of preanthesis flower E front view of open flower F lateral view of open flower G lateral view of young flower H longitudinal section of flower I gynostemium, ovary and pedicel. (Photographed by Y. H. Tan, H. B. Ding & B. Yang).
China. Yunnan: Gongshan, east of Dulong River, 27°41'51.81"N, 98°19'11.22"E, 1400 m a.s.l., 12 Nov. 1959, G.M. Feng. 24217 (KUN, No. 0163232).
1 | Perianth claret (deep purple red), outside densely brown hirsute with parallel dark purple veins | A. sinoburmanica |
– | Perianth yellowish, yellowish-white or white with purple to dark purple veins or dots | 2 |
2 | Leaf base slightly to deeply cordate | 3 |
– | Leaf base round, cuneate to rounded or rounded to truncate | 4 |
3 | Leaf blade broadly ovate to cordate | A. faviogonzalezii |
– | Leaf blade ovate-oblong to ovate-lanceolate | A. saccata |
4 | Throat yellow | A. hainanensis |
– | Throat white | 5 |
5 | Limb 3-lobed, lobes unequal, throat without visible dots | A. tonkinensis |
– | Limb 3-lobed, lobes subequal, throat densely covered with purple dots | A. xuanlienensis |
Aristolochia sinoburmanica is morphologically similar to A. faviogonzalezii, A. hainanensis, A. tonkinensis, A. saccata and A. xuanlienensis. However, the new species differs from the aforementioned species in several important vegetative and reproductive characters (summarised in Table
The authors are grateful to the Forest Research Institute of Myanmar for permission to conduct this study in Northern Myanmar and for their support and collaboration. We are grateful to many personnel in Myanmar for their exhaustive help in the field work. We are also grateful to Professor Richard T. Corlett for his thoughtful comments and constructive suggestions, which help to improve the quality of this manuscript. We thank Zhengmeng Yang for the illustration. This work was financially supported by a project of the Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences (Grant No.Y4ZK111B01).