Research Article |
Corresponding author: Yong Yang ( yangyong@njfu.edu.cn ) Academic editor: Elton John de Lirio
© 2022 Zhi Yang, Chaoyi Deng, Lulu Wang, Qiming Ban, Yong Yang.
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 Z, Deng C, Wang L, Ban Q, Yang Y (2022) A new species of Cinnamomum (Lauraceae) from southwestern China. PhytoKeys 202: 35-44. https://doi.org/10.3897/phytokeys.202.76344
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Field investigations in Guizhou, China, in 2020 resulted in the discovery of an unknown species of Lauraceae. Morphological studies revealed that it is a new species of Cinnamomum sect. Camphora Meisn., based on the large terminal buds, and alternate leaves with pinnate veins. It is distinguished from other species of sect. Camphora by the rather large perulate terminal buds with numerous bracts, larger flowers, oblong-elliptic linear tepals twice as long as the stamens, and the deep cup-shaped fruiting cupule. It is here described and illustrated as a new species, Cinnamomum guizhouense C.Y.Deng, Zhi Yang et Y.Yang. A key to distinguish it from related species in the same area is provided. In addition, we list the new species as Critically Endangered (CR), and suggest to conduct ex situ conservation, collect seeds and plant the species in botanic gardens.
Guizhou, morphology, sect. Camphora, taxonomy
Cinnamomum Schaeff. (
Recent botanical investigations to Wangmo County of Guizhou Province, one of the most botanical diverse regions of China, resulted in the discovery of a Cinnamomum species with unusual morphology, which led us to conclude that it is a new species for science. We conducted field investigations, estimated the population size and extent/area of occupancy, and collected several flowers and fruits of the plant. Specifically, we carried out morphological studies to answer the following questions: 1) what are the morphological affinities of the new species; and 2) what is the conservation status of the new species?
Field investigations were conducted and observations were made during February of 2020 and February of 2022. Specimens were collected, and flowers were fixed in FAA. Fresh and pickled flowers were dissected, observed and measured under a light microscope (GP-M101). Photographs were taken using a Nikon D7100 and a Sony A7M3 camera. We assessed the conservation status of the species by observing the population size and estimating the extent of occurrence (EOO) and the area of occupancy (AOO) and applying IUCN red list categories and criteria and guidelines (
China. Guizhou, Wangmo Co., Jiaona Tw., Babu Village, Liji Sect., 25°21'8"N, 106°17'44"E, elev. 1081 m, 20 Feb 2021, C.Y. Deng & Q.M. Ban 2021001 (holotype: NF; isotypes: NF, NAS, XIN).
Cinnamomum guizhouense is close to C. foveolatum (Merr.) H.W.Li et J.Li (
Trees, evergreen, 11–13 m tall, D.B.H. ca. 36 cm (Fig.
Morphology of Cinnamomum guizhouense C.Y. Deng, Zhi Yang et Y. Yang, sp. nov. a trunk b bud c flower branch d leaf adaxial surface e leaf abaxial surface f inflorescence g trimerous flower h tetramerous flower i stamen of first whorl j stamen of second whorl k stamen of third whorl with two glands at base l pistil m a young fruit with pedicel and cupule enclosing inner fruit n mature infructescence with deep, cup-shaped cupule. Bars: 30 cm (a); 1 cm (b, f–h, m, n); 3 cm (c-e); 1 mm (i–l).
Illustration of morphological characters of Cinnamomum guizhouense C.Y. Deng, Zhi Yang & Y. Yang, sp. nov. A leafy flowering branch with alternate, elliptic and obovate leaves, large terminal buds and inflorescences B, C variation in floral merosity B tetramerous flower C trimerous flower D stamen of first and second whorl E stamen of third whorl F staminode of fourth whorl G pistil H longitudinal section of young fruit with pedicel and cupule partially enclosing inner fruit I mature infructescence with peduncle and pedicel and deep cup-shaped cupule J subglobose seed.
The species is named after the province, Guizhou, where it occurs.
Cinnamomum guizhouense is known only from Wangmo Xian, Guizhou Province, southwestern China (Fig.
The new species lives in bamboo (Phyllostachys sp.) colonies in acidic soil with mean annual temperature 13–15 °C, annual precipitation 1000–1200 mm. It is heliophilous and lives on western slopes. The species lives near a village road with human disturbance, and the disturbance will not stop unless a new nature reserve is established to conserve the species. The species has an extremely small population, and only two individuals were found in the region. The living individuals occupy an area (EOO, ≈ AOO) ca. 100 m2.
On four instances of field investigations in the area, we found only two mature plants living within ca. 100 m2. We thus designate the species to be Critically Endangered (CR B1+2ab(iii); C1+2a(i); D) according to the IUCN red list categories and criteria (
The local people refer to C. guizhouense as Da Mu Jiang Zi (big Litsea), which is not in accordance with its formal taxonomic position. Here we name it Guizhou Cinnamon.
China. Guizhou, Wangmo Xian, Jiaona Tw., Babu Village, Liji Section, 25°21'8"N, 106°17'44"E, elev. 1081 m, 20 Feb 2021, C.Y. Deng & Q.M. Ban 2021002 (NF, XIN), 2021003 (NF, XIN); 21 Oct 2020, C.Y. Deng et al. 2020102111 (XIN); 20 Oct 2020, C.Y. Deng & J.B. Xu 2020102802 (XIN); 10 Jun 2021, C.Y. Deng & Q.M. Ban 2021061001 & 2021061002 (XIN).
Recent phylogenetic studies have suggested that Cinnamomum comprises two groups that largely, but not strictly, correspond to two sections of the genus (
Cinnamomum guizhouense is characterized by the large perulate terminal buds, flowers with tepals twice as long as the stamens, and deep fruiting cupules. This unique combination of morphological characteristics distinguishes C. guizhouense from all other species of sect. Camphora (
Morphological comparison of species of Cinnamomum sect. Camphora from Guizhou, China.
Species | Leaf size (cm) | Lateral veins | Petiole length (cm) | Inflorescence pubescence | Tepal shape | Tepal length (mm) | Stamen length (mm) | Cupule length (mm) |
---|---|---|---|---|---|---|---|---|
C. bodinieri | 8−17 × 3−10 | 4−6 | 2−3 | glabrous | ovate | 1.2 | 1 or a little longer | / |
C. camphora | 6−12 × 2.5−5.5 | 1−5(−7) | 2−3 | glabrous or gray- to yellow-brown puberulent | elliptic | 2 | 2 | 5 |
C. foveolatum | 9−15 × 3−5.5 | 6−8 | 1−1.3 | sparsely villous | outer ones ovate, inner ones broadly ovate | outer ones ca. 2 × 1.1, inner ones ca. 1.7 × 1.2 | 1.2−1.4 | 20 |
C. glanduliferum | 6−15 × 4−6.5 | 4 or 5 | 1.5−3.5 | glabrous | broadly ovate | 2 × 1.7 | 1.4−1.6 | 10 |
C. guizhouense | 12−21 × 6−9 | 5−7 | 2−4 | pubescent | oblong-elliptic to linear | 3−4 | 1.5−2 | 15 |
C. micranthum | 7.5−10 × 4−6 | 4 or 5 | 2−3 | subglabrous or slightly puberulent | narrowly ovate | 1.3 | 1 | 9 |
C. migao | 4.5−16 × 2.5−7 | 4 or 5 | 1.3−3 | pubescent | / | / | / | 12 |
C. parthenoxylon | 6−12 × 3−6 | 4 or 5 | 1.5−3 | glabrous | narrowly elliptic | 2 × 1.2 | 1.5−1.7 | 10 mm or less |
C. rufotomentosum | 15−16.5 × 4−5 | 4−6 | 2−2.9 | reddish brown tomentose | / | / | / | / |
C. saxatile | 5−13 × 2−5 | 5−7 | 0.5−1.5 | brownish puberulent | ovate | 3 | 4−4.5 | shallow |
We conducted field investigations on C. guizhouense on four occasions and found only two individuals in the area, suggesting that the species has an extremely small population. In addition, the new species lives near a village with human disturbance, the living habitat of C. guizhouense has not been improved and deterioration continues. We thus suggest to plan an ex situ conservation strategy for the new species, collect seeds and plant the species in botanic gardens.
1a | Tepals of flowers short, 1−2 mm long | 2 |
1b | Tepals of flowers 3−4 mm long | 4 |
2a | Fruiting cupule up to 20 mm long | C. foveolatum |
2b | Fruiting cupule ca. 5 mm long | 3 |
3a | Leaves 8−17 cm long; tepals ovate, 1.2 mm long; stamens 1 mm long | C. bodinieri |
3b | Leaves 6−12 cm long; tepals elliptic, 2 mm long; stamens 2 mm long | C. camphora |
4a | Buds 2−5 mm long; domatia present in the axils of lateral leaf veins; panicles 3−6 cm long; stamens 4−4.5 mm long; fruiting cupule shallow, 5−6.5 mm in diam | C. saxatile |
4b | Buds to 25 mm long; domatia absent in the axils of lateral leaf veins; panicles 7−10 cm long; stamens 1.5−2 mm long; fruiting cupule deep to 15 mm in diam | C. guizhouense |
We thank to J.B. Jin for his kind help with the field collections, H. Peng, B. Liu, and F.N. Wei for their valuable suggestions, D.E. Boufford for his kind help with language, and E.J. de Lirio, L. Li, A. Ortiz and M.L. Broto for their constructive suggestions on revision of the manuscript. We are also grateful to Z.X. Gu for the line-drawing. This work was supported by the National Natural Science Foundation of China [31770211, 31470301, 31270238] to YY and the Metasequoia fund of the Nanjing Forestry University.