Research Article |
Corresponding author: Yong Yang ( yangyong@njfu.edu.cn ) Academic editor: Elton John de Lirio
© 2021 Zhi Yang, Wei-Yin Jin, Bing Liu, David Kay Ferguson, 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, Jin W-Y, Liu B, Ferguson DK, Yang Y (2021) Big fruits with tiny tepals: An unusual new species of Lauraceae from southwestern China. PhytoKeys 179: 129-143. https://doi.org/10.3897/phytokeys.179.62050
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We collected an unusual new plant of Phoebe (Lauraceae) from southeastern Yunnan, China, which possesses more or less oblong leaves, paniculate inflorescences with strictly opposite lateral cymes, trimerous flowers with 4-locular stamens, and large fruits with tiny, equal, persistent tepals. Our molecular phylogenetic study based on nrITS, LEAFY and plastid matK sequences suggests that this species belongs to a clade of Phoebe including P. puwenensis, P. megacalyx, and P. macrocarpa. However, this species differs from the latter three species by subglabrous twigs, leaves and inflorescences (vs. pubescent twigs, leaves and inflorescences in the latter three species), larger fruits (5–8 cm long vs. 1–4 cm long in the latter three species), and smaller tepals (1–2.5 mm long vs. 5–15 mm long in the latter two species). As a result, Phoebe jinpingensis sp. nov. is described and illustrated here as new to science.
Lauraceae, morphology, new species, Phoebe, phylogeny, taxonomy
The Lauraceae are woody plants, except for the hemiparasitic climber genus Cassytha L. (
Phoebe Nees (
Recently, we collected both flower and fruit materials of one notable tree species while conducting field investigations in southeastern Yunnan, China. Further morphological and molecular phylogenetic studies indicate that this species is a new species of Phoebe. We thus describe it here as new to science.
We conducted field collections and morphological observations, obtained voucher specimens, preserved flowers in FAA, and dried leaf materials with silica gel. Photographs of vegetative and reproductive characters were taken with a Nikon camera (D700). The preserved flowers were dissected and observed, and photographs were taken under a stereo microscope (Leica S8APO).
To determine the systematic position of our new species, we conducted a phylogenetic study using nrITS, LEAFY and plastid matK sequences. This phylogeny included 40 species from five genera of the Persea group (Alseodaphne, Alseodaphnopsis, Dehaasia, Machilus and Phoebe). Litsea acuminata (Blume) Sa. Kurata (
Sequences obtained in this study and their vouchers. All voucher specimens are deposited in PE.
Species | ITS | LEAFY | matK | Voucher specimen | Locality |
---|---|---|---|---|---|
Alseodaphne huanglianshanensis H.W.Li & Y.M.Shui | MW826229 | MW849576 | MW849603 | Bing Liu 2447 | China, Yunnan |
Alseodaphnopsis andersonii (King ex Hook.f.) H.W.Li & J.Li | MW826228 | MW849575 | MW849602 | Bing Liu 1584 | China, Yunnan |
Alseodaphnopsis hokouensis (H.W.Li) H.W.Li & J.Li | MW826237 | MW849583 | MW849610 | Bing Liu 2358 | China, Yunnan |
Alseodaphnopsis petiolaris (Meisn.) H.W.Li & J.Li | MW826234 | MW849580 | MW849607 | Bing Liu 1266 | China, Yunnan |
Alseodaphnopsis sichourensis (H.W.Li) H.W.Li & J.Li | MW826235 | MW849581 | MW849608 | Bing Liu 1980 | China, Yunnan |
Alseodaphnopsis ximengensis H.W.Li & J.Li | MW826236 | MW849582 | MW849609 | Bing Liu 4726 | China, Yunnan |
Dehaasia incrassata (Jack) Kosterm. | MW826238 | MW849585 | MW849612 | X.H.Jin IN004 | Indonesia. |
Litsea acuminata (Blume) Kurata | MW826239 | MW849586 | MW849613 | Y.Yang, T.T.Sun & W.Y.Jin 2016110811 | China, Taiwan |
Litsea akoensis Hayata | MW826240 | MW849587 | MW849614 | Y.Yang, T.T.Sun & W.Y.Jin 2016110810 | China, Taiwan |
Machilus bonii Lec. | MW826241 | MW849588 | MW849615 | Bing Liu 2133 | China, Yunnan |
Machilus breviflora (Benth.) Hemsl. | MW826242 | MW849589 | MW849616 | Bing Liu 1827 | China, Guangdong |
Machilus melanophylla H.W.Li | MW826243 | MW849590 | MW849617 | Bing Liu 1950 | China, Yunnan |
Machilus robusta W.W.Sm. | MW826244 | MW849591 | MW849618 | Bing Liu 1524 | China, Yunnan |
Phoebe angustifolia Meisn. | MW826246 | MW849620 | Bing Liu 1490 | China, Yunnan | |
Phoebe cavaleriei (H.Lév.) Y.Yang & Bing Liu | MW826245 | MW849619 | Bing Liu 2215 | China, Yunnan | |
Phoebe chekiangensis C.B.Shang | MW826247 | MW849592 | MW849621 | Bing Liu 2232 | China, Hubei |
Phoebe formosana (Hayata) Hayata | MW826248 | MW849593 | MW849622 | Y.Yang, T.T.Sun & W.Y.Jin 2016110836 | China, Taiwan |
Phoebe jinpingensis Liu B. 1477 | MW826231 | MW849584 | MW849611 | Bing Liu 1477 | China, Yunnan |
Phoebe jinpingensis Liu B. 2050 | MW826232 | MW849578 | MW849605 | Bing Liu 2050 | China, Yunnan |
Phoebe jinpingensis Liu B. 2052 | MW826233 | MW849579 | MW849606 | Bing Liu 2052 | China, Yunnan |
Phoebe jinpingensis Liu B. 2417 | MW826230 | MW849577 | MW849604 | Bing Liu 2417 | China, Yunnan |
Phoebe lanceolata (Wall. ex Nees) Nees | MW826249 | MW849594 | MW849623 | Bing Liu 2532 | China, Yunnan |
Phoebe macrocarpa C.Y.Wu | MW826250 | MW849595 | MW849624 | Bing Liu 1239 | China, Yunnan |
Phoebe megacalyx H.W.Li | MW826251 | MW849596 | MW849625 | Bing Liu 1988 | China, Yunnan |
Phoebe nanmu (Oliv.) Gamble | MW826252 | MW849597 | MW849626 | Bing Liu 2227 | China, Yunnan |
Phoebe neurantha var. brevifolia H.W.Li | MW826253 | MW849598 | MW849627 | Bing Liu 2270 | China, Yunnan |
Phoebe neurantha (Hemsl.) Gamble | MW826254 | MW849599 | MW849628 | Bing Liu 1570 | China, Yunnan |
Phoebe puwenensis W.C.Cheng | MW826255 | MW849600 | MW849629 | Bing Liu 2242 | China, Yunnan |
Phoebe sheareri (Hemsl.) Gamble | MW826256 | MW849601 | MW849630 | Bing Liu 2224 | China, Hubei |
Phoebe tavoyana (Meisn.) Hook.f. | MW826257 | – | MW849631 | Bing Liu 1822 | China, Hainan |
Total DNA was extracted from silica-gel-dried leaves using Tiangen Plant Genomic DNA kits. To amplify the nrITS, LEAFY and plastid matK fragments, we followed
Sequences were edited with Sequencher 4.1.4 (Gene Codes Corporation, Ann Arbor, Michigan, USA), aligned using MAFFT 7 (
The line drawing was done manually with a black ink pen. Illustrations and photos showing morphological characters were edited and merged in Adobe Photoshop CS2 ver. 9.0. Phylogenetic trees were browsed and adjusted in FigTree ver. 1.4.0 (
Extinction risk was assessed using IUCN categories and criteria (
China. Yunnan Province: Jinping County, Mengla, Tuomazhai, 22°37'N, 103°01'E, elev. 956 m, 8 Apr 2014, B.Liu, Y.Yang, Q.W.Lin, L.Jiang & X.J.Li 2050 (holotype: PE!; isotypes: PE!).
This species is similar to P. macrocarpa C.Y.Wu (
Trees (Fig.
Anatomy of a flower of Phoebe jinpingensis sp. nov. showing morphology of stamens, staminodes, and pistil A stamens of the first staminal whorl, adaxial side B stamen of the first staminal whorl, abaxial side C stamen of the second staminal whorl, adaxial side D stamen of the second staminal whorl, abaxial side E stamen of the third staminal whorl, adaxial side F stamen of the third staminal whorl, abaxial side G staminode of the fourth staminal whorl, adaxial side H staminode of the fourth staminal whorl, abaxial side I pistil.
Line-drawing showing details of Phoebe jinpingensis sp. nov. A a flowering branch B fruits C fertile stamens of the first staminal whorl, abaxial side D fertile stamens of the first staminal whorl, adaxial side E fertile stamen of the third staminal whorl with the two glands at the base of the filaments, adaxial side F fertile stamen of the third staminal whorl with the two glands at the base of the filaments, abaxial side G staminode of the fourth staminal whorl showing pubescence, abaxial side H staminode of the fourth staminal whorl showing pubescence, adaxial side I pistil, with obovoid pubescent ovary and linear style.
This species occurs in montane evergreen forests at an altitudinal range of 900–980 m. It blooms in April, and the fruits mature from September to December.
The specific epithet ‘jinpingensis’ refers to the type locality “Jinping County”.
China. Yunnan Province: Jinping County, Mengla, Tuomazhai, 8 Apr 2014, fruit, B.Liu, Y.Yang, Q.W.Lin, L.Jiang & X.J.Li 2052 (PE!); Jinping County, Mengla, Tuomazhai, 9 Oct 2011, fruit, B.Liu 1477 (PE!); Jinping County, Mengla, Tuomazhai, 14 Sep 2014, fruit, B.Liu, Y.Song, H.Lai & X.Yao 2417 (PE!).
There is only one population with 10 mature individuals occupying ca. 400 m2. Fewer than 10 juvenile individuals were found. All the individuals have not been protected in any nature reserve, and a rubber plantation exists nearby the population. Based on IUCN Red List Categories and Criteria (
We finally obtained 30 sequences of nrITS, 27 sequences of LEAFY and 30 sequences of matK (Table
The best-fit nucleotide substitution model of the three markers for both BI and ML analyses.
Analysis | nrITS | LEAFY | matK |
---|---|---|---|
BI | HKY+F+I+G4 | HKY+F+G4 | HKY+F+I |
ML | HKY+F+G4 | HKY+F+G4 | HKY+F |
Item | nrITS | LEAFY | matK | all |
---|---|---|---|---|
Sequence length (nt) | 745 | 896 | 763 | 2404 |
Variable (polymorphic) sites (nt) | 149 | 158 | 22 | 329 |
Parsimony informative sites (nt) | 98 | 57 | 13 | 168 |
Our phylogenetic study gave rise to BI and ML trees showing similar topology (Figs
Machilus was monophyletic (BS: 100 and PP: 1). Alseodaphne huanglianshanensis H.W.Li & Y.M.Shui (
Modern taxonomy is based on phylogeny. There is no phylogeny with full sampling of Phoebe, only a few molecular phylogenetic studies including partial sampling of the genus (
The genus Phoebe possesses persistent appressed tepals at the base of the fruits, whereas Alseodaphne and Alseodaphnopsis have fruits lacking persistent tepals (
Phoebe jinpingensis is unusual in the genus Phoebe. First, the fruit is very large and avocado-shaped. Second, the tepals of P. jinpingensis are quite tiny (1–2.5 mm long) and concealed and not obvious in well-developed swollen fruits (Fig.
The genus Phoebe usually possesses small fruits ca. 1 cm, the largest fruits being seen in P. megacalyx (ca. 3.2 cm long) and P. macrocarpa (3.5–4.2 cm long) (
1 | Leaves, inflorescences, and twigs subglabrous; fruits large, up to 8 cm long, having tiny tepals ca. 2–2.5 mm long | P. jinpingensis |
– | Leaves, inflorescences, and twigs usually tomentose or pubescent; fruits smaller, usually ca. 1–4 cm, possessing bigger tepals 5 mm or longer | 2 |
2 | Fruits 3–4 cm long | 3 |
– | Fruits 1–2 cm long | P. puwenensis |
3 | Leaves asymmetrical at the base; tepals woody, ca. 15 mm long | P. megacalyx |
– | Leaves symmetrical at the base; tepals coriaceous, 5–6 mm long | P. macrocarpa |
We thank Henk van der Werff of Missouri Botanical Garden and George Staples of Harvard University for their valuable suggestions and Y.F.Li for his kind help with the line-drawing. We are also grateful to L.Li, L.Assis and J.G.Rohwer for their constructive suggestions on the manuscript. This work was supported by the National Natural Science Foundation of China [31970205, 31470301, 31770211] and the Metasequoia funding of Nanjing Forestry University.
Figures S1–S8, Tables S1–S3
Data type: Phylogenetic trees and tables
Explanation note: Figures S1–S8. Phylogenetic trees. Figures S1–S6. BI and ML trees of Asian species of the Persea group using single markers. Figures S7, S8. BI and ML trees of the Persea group using concatenated sequences of nrITS, LEAFY and matK. Table S1. Sequences obtained from NCBI for phylogeny of the Persea group. Table S2. Substitution models of nrITS, LEAFY and matK for phylogeny using separate markers. Table S3. A tabulated comparison of fruit size of Phoebe from China.