doi: 10.1111/njb.01735 00 1–4

NORDIC JOURNAL OF BOTANY Research Amomum hainanense (), a new species from Hainan, China

Pu Zou, Rong-Tao Li, Yu-Shi Ye, Jian-Ping Huang and Jing-Ping Liao

P. Zou (http://orcid.org/0000-0001-9060-0891) and J.-P. Liao, Key Laboratory of Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, P. R. China. JPL also at: Guangdong Provincial Key Laboratory of Applied Botany, Guangzhou, P. R. China. – R.-T. Li, Hainan Branch of Inst. of Medicinal Plant Development, Chinese Academy of Medical Sciences, Haikou, P. R. China. – Y.-S. Ye ([email protected]), Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, P. R. China. – J.-P. Huang, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun Town, Mengla County, Yunnan, P. R. China.

Nordic Journal of Botany Amomum hainanense sp. nov., a new species of the Amomum (Zingiberaceae), 2018: e01735 is described and illustrated from the Hainan Province, China. The species is closely doi: 10.1111/njb.01735 related to A. repoeense and A. plicatum, but can be distinguished from the latter by being less tall and having few flowers that are open simultaneously (only two), a Subject Editor: Xiang-Yun Zhu membranous ligule and 6–8-winged fruit ridges (not 9-winged). The species is known Editor-in-Chief: Torbjörn Tyler only from Hainan Island. Accepted 27 September 2018

Introduction

Amomum Roxb. (Roxburgh 1820) is currently recognized as the second largest genus of Zingiberaceae after Alpinia Roxb. (Roxburgh 1810). It has 150–180 species and is widely distributed from Sri Lanka to the Himalayas, China, southeast Asia, Malesia and northern Australia, with the distribution center in the Malesian region (Larsen et al. 1998, Droop and Newman 2014). In China, there are 38 (28 endemic, one introduced) species of Amomum (Wu and Larsen 2000, Zou et al. 2016). Many of them are used in traditional Chinese medicine and Amomum tsao-ko Crevost & Lemarié is a famous food condiment (Xia et al. 2004). During fieldwork on Hainan in 2010, we found an interesting species in the wild which the local people thought was Amomum repoeense Pierre ex Gagnep. or A. maximum Roxb. (Wu and Larsen pers. comm.). But after growing and studying it in the South China Botanical Garden, Academy of Sciences, for three years we believe it to be a new species as described and illustrated below.

Amomum hainanense Y. S. Ye, J. P. Liao & P. Zou sp. nov. (Fig. 1–2)

Similar to Amomum repoeense Pierre ex Gagnep. and A. plicatum Lamxay & M.F.Newman (Lamxay and Newman 2012) in blade and flower type and fruit shape, but differing by having low plant height and only 2 simultaneously open flowers (vs 4 or 6), a membranous ligule (vs papery or coriaceous) and 6–8-winged fruit ridges (vs 9-winged) (Table 1). –––––––––––––––––––––––––––––––––––––––– © 2018 The Authors. Nordic Journal of Botany © 2018 Nordic Society Oikos www.nordicjbotany.org

1 Figure 1. Images of Amomum hainanense sp. nov. (A) habitat, (B) habit (scale bar = 10 cm), (C) rhizome, (D) fruits, (E) detail of ovary with epigynous glands, (F) stamens in side view and the style, (scale bar in cm), (G) dissection of flowers (from left): calyx, corolla lobes, labellum, floral tube with anther and ovary, (H) detail of leaf ligule, (I) inflorescence (the two flowers open at the same time). Photos (A), (B) and (G) by Zou Pu and the others by Ye Yu-Shi.

Type: China, Hainan, Qiongzhong, Limushan, 19°10′24″N, with secondary veins prominent, uneven. Inflorescences 109°43′56″E, 680 m a.s.l., 26 May 2016, ZP 52 (holotype: arising near the base of the plant, with one to four flow- IBSC (796523), isotypes: IBSC). ers, usually three per pseudostem, with two flowers simul- taneously open; peduncle 3–5 cm, reddish–brown, striate, Etymology pubescent; scale like sheaths 0.6–2.0 × 0.4–0.7 cm, initally The name refers to the fact that the species is so far only reddish, turning dark brown with age, papery when dried, found on Hainan Island. with outer surface pubescent, emarginate at apex, ciliate along margin; bracts ovate, 1.8–2.0 × 1.2–1.5 cm, initally Description reddish, turning dark brown with age, usually early rotten, Perennial herb, 30–60 cm tall, with 3–4 pseudostems per fleshy, subtending a single flower, pubescent, acuminate at clump; rhizome ca 0.5 cm in diameter, red; stilt roots absent; apex; bracteole lanceolate, 0.8–1.3 × 0.3–0.5 cm, reddish– interval between pseudostems 3–6 cm. Pseudostem with brown, fleshy (membranaceous when dried), with outer sur- 2–7 leaves per pseudostem, 1.5–2.5 cm in diameter, green, face pubescent, acuminate at apex; pedicel 0.6–0.9 cm long, striate, puberulent. Ligule lanceolate, bi-lobed, 0.8–1.5 cm reddish–brown. Calyx tubular, 3-toothed, 1.8–2.2 cm long, long, turning brown, membranous, sometimes deflexed, red, membranaceous, with outer surface pubescent, acute its outer surface villose, acute at apex. Petiole canaliculate, at apex. Corolla ca 1.8 cm, 0.5–0.6 cm wide, white, with 6–10 cm long, striate, green, villose; lamina oblong to ellip- red dots at the base and apex; corolla tube 1.8–2.2 cm long, tic, 20–35 × 8–13 cm, green, adaxially glabrous, abaxially membranaceous, with outer surface pubescent; lateral corolla densely pubescent, attenuate at base and apex, inequilateral lobes ca 1.6 × 0.5 cm, membranaceous, glabrous, cucullate at

2 Figure 2. Amomum hainanense sp. nov. (A) flower, (B) close-up of adaxial surface of labellum, showing the stripe and lines, (C) detail of style with epigynous glands, (D) adaxial view of the bract, (E) calyx, (F) close-up of the central corolla lobe, (G) adaxial view of the stamen, (H) close-up of the whole plant. Illustration by Yun-Xiao Liu based on the holotype ZP 52 (796523) (IBSC). apex; central corolla lobe 1.7–1.8 × 0.6–0.7 cm, membrana- long, white, with glandular trichomes. Filament flattened, ceous, glabrous, cucullate at apex; labellum clawed, 2.8–3.1 0.3–0.4 cm long, white, with glandular trichomes; anther × 2.5–2.7 cm, connate with filaments into a tube 0.1–0.2 cm oblong, 0.6–0.7 cm, white, with glandular trichomes; anther above the insertion of the corolla lobes, tri-lobed, white with crest truncate, entire, very short, ca 0.1 cm, white, membra- a yellow central stripe edged with lines of red dots which naceous, glabrous. Stigma funnel-shaped, with glandular tri- radiate to margin, membranaceous, pubescent at base and chomes; style linear, glabrous; epigynous glands two, oblong, along the central part, rounded and shallowly lobed at apex; 0.3 cm long, fawn, glabrous; ovary 0.3–0.4 × 0.5–0.6 cm, lateral staminodes rather narrowly triangular, 0.1–0.2 cm its pedicel ca 0.6 cm long, with 6–8 longitudinal ridges at

Table 1. Comparison of morphological characters of Amomum hainanense sp. nov., A. repoeense Pierre ex Gagnep. and A. plicatum Lamxay & M.F.Newman.

Characteristics A. hainanense A. repoeense A. plicatum Habit (cm) 30–60 50–100 100–120 Leaves per pseudostem ca 2–7 ca 3–4 ca 6–7 Blade (cm) 20–35 × 8–13 32–45 ×7–12 12–35(–50) × 5–10(–20) Ligule 0.8–1.5 cm long, membranous 2–4 cm long, papery 0.3–1.0 cm long, coriaceous Inflorescences per pseudostem 1–2 2–3 1–3 Flowers simultaneously open ca 2 ca 6 ca 4 Anther crest truncate, entire tri-lobed tri-lobed Ovule number ca 10 per locule ca 15 per locule ca 25 per locule Fruit ridges 6–8-winged; margin straight 9-winged; margin straight 9-winged; margin undulate

3 base, hairy; ovules globose, ca 10 per locule. Infructescence Vernacular name peduncle 3–4 × 0.5 cm, initally red, turning brown with 海南豆蔻 (in Chinese). age, glabrous; capsule ovoid, at apex with persistent calyx, ca 2.0–2.8 × 1.0–1.8 cm, with 6–8 longitudinal ridges, initially Additional specimen examined (paratype) reddish-brown, turning black when mature, its wings 0.1– China: Hainan: Sanya, Baishiling Shan, 400 m a.s.l., 15 May 0.2 cm wide with straight margins, pubescent. Seeds ovate, 1988, Z. X. Li and F. W. Xing 4532 (IBSC). 0.3–0.4 × 0.2–0.3 cm, black, with gray–white aril.

Phenology Acknowledgments – We thank Mr Xiu-Hai Huang for his help in Amomum hainanense is known to flower in May to June and the fieldwork. This work was supported by the National Natural Science Foundation of China (grant no. 31470410, 30900089); have young fruit in May in the wild (Z. X. Li and F. W. Xing the Natural Science Foundation of Guangdong Province, China 4532, IBSC!). However, it has mature fruit in August in the (2015A030313865); and the Compilation of Ex Situ Cultivated cultivation (Fig. 1D). Flora of Botanical Gardens (2015FY210100).

Distribution and habitat Only found in Hainan Diaoluo Shan, Limu Shan and Sanya References Baishiling Shan. It grows in tropical rainforest valleys. Droop, A. J. and Newman M. F. 2014. A revision of Amomum Conservation status (Zingiberaceae) in Sumatra. – Edinb. J. Bot. 71: 193–258. During fieldwork in 2010 the corresponding author discov- IUCN 2012. IUCN red list categories and criteria, ver. 3.1, 2nd ered the species in Diaoluo Shan and the other authors found ed. – IUCN Species Survival Commission. the same species in Limu Shan where no more than twenty Lamxay, V. and Newman, M. F. 2012. A revision of Amomum individuals of this species grew in about 1 km2. According (Zingiberaceae) in Cambodia, Laos and Vietnam. – Edinb. J. Bot. 47: 1–75. to the IUCN red list categories and criteria (IUCN 2012), Larsen, K. et al. 1998. Zingiberaceae. – In: Kubitzki, K. (ed.), A. hainanense should be categorized as a ‘Vulnerable’ (VU) The families and genera of vascular . Vol. 4. Springer, species. It is worth pointing out that in China species of pp. 474–495. Amomum are often harvested as medicines by local people, Roxburgh, W. 1810. Descriptions of several of the monandrous which may potentially affect the survival ofA. hainanense and plants of India, belonging to the natural order called Scitamineae its congeners. by Linnaeus, Cannae by Jussieu, and Drimyrhizae by Ventenat. – Asiat. Res. 11: 350. Similar species Roxburgh, W. 1820. Amomum – In: Flora Indica. Vol. 1. Mission Amomum hainanense has the inflorescences arising from the Press, pp. 37–46. base, white flowers and winged fruits, and is thus morpho- Wu, D. L. and Larsen, K. 2000. Zingiberaceae. – In: Wu, Z. Y. and logically similar to A. repoeense and A. plicatum. However, Raven, P. H. (eds), Flora of China. Vol. 24. Science Press; Miss. it is readily distinguishable by the shorter plant height (only Bot. Gard. Press, pp. 322–377. Xia, Y. M. et al. 2004. Phylogenetic analyses of Amomum 30–60 cm tall) and fewer simultaneously open flowers (only (Alpinioideae: Zingiberaceae) using ITS and matK DNA two). The anther crest is truncate and entire in A. hainanense sequence data. – Syst. Bot. 29: 334–344. but tri-lobed in A. repoeense and A. plicatum. Moreover, the Zou, P. et al. 2016. Alpinia austrosinense (Zingiberaceae), a new latter two species also have more flowers, ovules and fruit combination from China and its relationship with A. pumila. ridges than A. hainanense. – Phytotaxa 255: 175–178.

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