A 200-year-long miscognition: Castanopsis cuspidata (Fagaceae) does not occur on the Korean Peninsula
Article information
Abstract
There has been no doubt over the past approximately 200 years that Castanopsis cuspidata is distributed on the Korean Peninsula. Nevertheless, our empirical observations prompt us to question its presence in this region. To clarify whether C. cuspidata occurs on the Korean Peninsula, we investigated specimens from herbaria, literature related to its distribution, and an officially recorded C. cuspidata forest of a Natural Monument on Yokjido Island. Based on our research findings, we provide a taxonomic key highlighting morphological differences especially the rachis of the infructescence and the tubercles of cupule between C. cuspidata and C. sieboldii. We concluded that it is more likely that C. cuspidata is not distributed on the Korean Peninsula. Furthermore, all the trees in the officially recorded natural monument C. cuspidata forest on Yokjido Island were found to be C. sieboldii. The miscognition may have gradually solidified over time due to a series of misidentifications of C. sieboldii. It began Wenzig’s documentation (1886) of Wilford’s specimen collection (1859) for Quercus cuspidata (= C. cuspidata) on Geomun Island in a historical context when the distinction between C. cuspidata and C. sieboldii had not yet been established. Additionally, our study suggests that the misidentification of organisms can have an impact beyond medicine and pharmacology, extending even into human culture.
INTRODUCTION
On the Korean Peninsula, a narrow zone extends along the western to the southern coast, including approximately 3,000 islands, where evergreen broad-leaved trees dominate (Lee et al., 2014). These distinctive tree species distribution boundaries categorize this narrow band-like zone within the Korean Peninsula as a Southern Coast Floristic Province (Lee and Yim, 2002). Additionally, the Jejudo Floristic Province and Ulleungdo Floristic Province also feature forests dominated by evergreen broad-leaved trees. Among the evergreen broadleaved trees found on the Korean Peninsula, particularly trees species within Fagaceae are the major componenst in the Jejudo and the Southern Coast Floristic Provinces. These include five species of Quercus (Q. acuta Thunb., Q. myrsinifolia Blume, Q. gilva Blume, Q. salicina Blume, and Q. glauca Thunb.) and two of Castanopsis [C. sieboldii (Makino) Hatus. ex T.Yamaz. & Mashiba and C. cuspidata (Thunb.) Schottky] (Chang and Kim, 2018). However, the empirical observations of the authors of this study, who possess expertise in plant taxonomy (Chung et al., 2023; Han et al., 2023; Jang et al., 2023), prompt us to question the presence of C. cuspidata on the Korean Peninsula.
Certainly, elucidating the distribution of a specific plant species is a scientific essence that goes beyond enhancing the accuracy of phytogeographical research. Reporting the new distribution of a species previously undocumented on the Korean Peninsula is not a difficult task upon confirmation of its presence. On the contrary, providing a contradictory view for a species known to be distributed on the Korean Peninsula is considerably challenging due to the inherent impossibility of thoroughly surveying the entire Korean Peninsula. Nevertheless, Park et al. (2011) reported the absence of Artemisia scoparia Waldst. & Kit., a plant long known to be distributed in the Korean Peninsula, through their specimen examinations and literature reviews. Their suggestion has been maintained and remains valid among researchers to this day.
MATERIALS AND METHODS
We began by examining historical records, tracing the initial documentation of C. cuspidata’s distribution on the Korean Peninsula, and scrutinizing how it has been documented in the literature. Subsequently, we investigated whether any distinct morphological traits differentiate C. cuspidata from C. sieboldii. We conducted an examination of Castanopsis specimens related to our concerns in the Korea National Arboretum (KH), the National Institute of Biological Resources (KB), and the Kyoto University Herbarium (KYO) (Appendix 1). Finally, we conducted a field survey to identify the trees of C. cuspidata designated as Natural Monument No. 343 on Yokjido Island in Tongyeong, Gyeongsangnam-do. As this constitutes an official record for C. cuspidata, we believe that it would serve as substantial evidence to support our claim.
RESULTS
Historical literature review
The miscognition that C. cuspidata is distributed on the Korean Peninsula was initiated from Wenzig’s documentation (1886) of Wilford’s specimen collection. Wilford’s specimens, collected on Geomundo Island (formerly known as Port Hamilton) in 1859, was identified as Quercus cuspidata Thunb (presumably C. sieboldii: Wenzig, 1886; Forbes and Hemsley, 1889). At this time, the distinction between C. cuspidata and C. sieboldii had not yet been established, leading to its recognition as Q. cuspidata. It was only later, in 1909, that Makino established a distinction between C. cuspidata (= Pasania cuspidata var. thunbergii Makino) and C. sieboldii (= Pasania cuspidata var. sieboldii Makino) (Makino, 1909). Nakai accepted Q. cuspidata in his early work (Nakai, 1911) by referencing Wenzig (1886), Forbes and Hemsley (1899). However, in his subsequent work (Nakai, 1917), he recognized C. sieboldii, according to Makino’s species concept and thereby distinguishing the two species. This work (Nakai, 1917) also described the distribution of the two species on the Korean Peninsula, mentioning the occurrence of C. cuspidata on Jejudo Island and C. sieboldii on both Jejudo Island and the southern coast.
In major literatures related Korean Peninsula flora (Lee, 1996; Lee, 2003; Chang and Kim, 2018), C. cuspidata and C. sieboldii were described as co-occurring on Jejudo Island and Korean southern coast. We believe that this distribution of C. cuspidata in the major Korean Peninsula floras was an unreserved acceptance of the distribution described in historical literature, without any questioning.
Examination of key morphological traits and specimens
We examined specimens of C. cuspidata and C. sieboldii at the Korea National Arboretum (KH), the National Institute of Biological Resources (KB), and the Kyoto University Herbarium (KYO). Our goal was to investigate whether there are any distinct morphological traits that distinguish C. cuspidata from C. sieboldii and to determine whether C. cuspidata is distributed on the Korean Peninsula.
Bark fissure, leaf shape, color of the abaxial leaf surface, as well as the size and shape of nuts were previously utilized to differentiate between C. cuspidata and C. sieboldii. However, these traits may not offer distinct boundaries, particularly given their morphological variability observed across different growth and developmental stages. One significant illustration of this variability is found in the size and shape differences of the nuts, contributing significantly to misidentification. Notably, we found that there is a recurring tendency to misidentify immature nuts of C. sieboldii as those of C. cuspidata. Similarly, the C. cuspidata specimen collected by Nakai from Jejudo Island in 1917 may appear to be C. cuspidata due to its small nuts. However, the short apex on its leaves, the stout rachis of the infructescence, and the cupule without tubercles led to its re-identification as C. sieboldii (Fig. 1). A taxonomic key distinguishing between C. cuspidata and C. sieboldii is as follows (Fig. 2):
1. Twigs and rachis of infructescence rather stout; leaves ovate-oblong or oblong, apex acuminate or long acuminate; cupule without tubercles; nut ovoid-elliptic or ovoidoblong, 1.2–2.1 cm (length/width = 1.4–2.2) ···················· ············································································ C. sieboldii
1. Twigs and rachis of infructescence slender; leaves narrowly lanceolate or oblong, apex caudate; cupule with tubercles; nut ovoid-globose, 0.6–1.3 cm (length/width = 0.8–1.3) ···· ··········································································· C. cuspidata
A. Castanopsis sieboldii (Jejudo Island, Korea, 2 Nov 1917, T. Nakai 4906 TI). B. C. sieboldii misidentified as C. cuspidata (Jejudo Island, Korea, 2 Nov 1917, T. Nakai 4907 TI). 1, Castanopsis specimens from Jejudo Island collected by Nakai; 2, leaf; 3, infructescence.
A. Castanopsis sieboldii (Makino) Hatus. B. C. cuspidata (Thunb.) Schottky. 1, specimen [A1: C. sieboldii (Hansando Island, Tongyeong-si, Gyeongsangnam-do, Korea, 23 Aug 2010, Tongyeong-si (Hansando)-100823-047 KH); B1, C. cuspidata (Yamauchi, Nakatosa, Kochi Pref., Shikoku, Japan, 4 Oct 2003, T. Miyazaki 0310028 KH)]; 2, leaves; 3, infructescence; 4, cupule; 5, nuts.
On the other hand, the lack of information about some historical specimens has left us with a lingering sense of not having found more conclusive evidence. The collection of Wilford could not be observed, as it was not traceable through the herbarium database.
Investigation and re-identification of C. cuspidata trees in the Natural Monument Forest on Yokjido Island
The C. cuspidata forest adjacent to the coast on Yokjido Island was designated as Natural Monument No. 343 in 1984, acknowledging its significance as a fishing forest that provides shade for the beach and creates a suitable environment for fish habitat. This forest is where C. cuspidata is officially known to be distributed on the Korean Peninsula. We investigated the C. cuspidata Forest on Yokjido Island during the flowering and fruiting seasons to confirm the identity of Castanopsis trees within the forest. Upon our investigation of the Castanopsis trees in the forest based on the key morphological traits described above, it was confirmed that all individuals were C. sieboldii rather than C. cuspidata. These findings support our argument that C. cuspidata does not occur on the Korean Peninsula.
On the other hand, during our investigation of the C. cuspidata forest on Yokjido Island, we propose corrections for several errors identified from a plant taxonomist’s perspective. Firstly, the left photo on the guide board (Fig. 3, B2) was of Q. acuta and required replacement. Next, the term “Forest of Cyathea Cuspidata” on the explanation board (Fig. 3, D2) referred to the scientific name of the tree fern and should thus be corrected to the appropriate English name. According to the Checklist of Vascular Plants in Korea (Korea National Arboretum, 2022), the recommended English name for C. sieboldii is “Siebold’s chinquapin”. Further corrections are presented in Table 1.
Castanopsis cuspidata Forest on Yokjido Island (Natural Monument No. 343). A. View. B. Guide board (1, full guide board; 2, zoomed in area of a photo; 3, another guide board’s photo). C. Label’s spring (1, securing the spring; 2, wounds). D. Explanation board (1, full guide board; 2, zoomed in area of an English explanation).
Recommendations for guide and explanation board corrections.
In an effort to conserve them, each individual was labeled for monitoring purposes. The labels were secured with springs. However, it appears that this spring labeling is inhibiting the development of bark and secondary growth, meaning that corrective action needs to be taken (Fig. 3, C1, C2).
DISCUSSION
Our conclusion leaned towards the higher likelihood that C. cuspidata is not distributed on the Korean Peninsula. Since the Convention on Biological Diversity (CBD), efforts to protect each country’s biological resources, known as ‘bio-resource wars’, have intensified, focusing on inventorying species and discovering new, undocumented ones. Unfortunately, our work appears to have contributed to a reduction in the number of identified national biological species in Korea. However, the misidentification or misnaming of organisms can have unfortunate consequences not only for the accuracy and repeatability of biological works but also in critical domains such as medicine, pharmacology, breeding, agriculture, conservation biology, ecosystem management, and climatology (Dubois et al., 2013).
The introduction of Korean flora to the Western botanical community through scientific methods occurred in the mid-19th century (Sun et al., 2019). The miscognition that C. cuspidata is distributed on the Korean Peninsula was initiated from the documentation (1886) of a specimen collection (1859) for Q. cuspidata (= C. cuspidata) on Geomun Island during a historical context when the distinction between C. cuspidata and C. sieboldii had not yet been established. In addition, over time, a series of misidentifications of C. sieboldii may have contributed to the gradual solidification of the miscognition. The accumulated miscognition, despite the actual trees on Yokjido Island being C. sieboldii, has led to the naming (1984) and continued maintenance of the forest as the C. cuspidata Natural Monument Forest up to the present. This study highlights the significance of taxonomy, suggesting that the misidentification of organisms can potentially influence human culture.
Acknowledgements
We are grateful to the persons concerned at the KH, KB, and KYO herbaria for permitting the examination of specimens. This study was supported by the Korea National Arboretum (KNA1-1-18, 15-3).
Notes
CONFLICTS OF INTEREST
The authors declare that there are no conflicts of interest.
References
Appendices
Appendix 1. Specimens examined
Cuspidata cuspidata: JAPAN. Honshu: Mie pref., Owase-shi, Kuki, Kuki Shrine, 10 Oct. 2004, S. Fujii 10400 (KYO); Shiga Pref., Inubami-gun, Koura-cho, Ogawabara, 10 Oct. 1985, M. Ito 7021 (KYO). Kyushu: Kagoshima pref., Tarumizu City, Western foot of Mt. Takauama, 25 Sep. 1983, H. Takahashi 7492 (KYO). Shikoku: Kouchi Pref., Tosa-shi, Kitahara, Funato, 17 Nov. 1975, M. Okamoto 1545 (KYO); Kouchi Pref., Nakatosa Town, Between Kaminokae and Umagura, 15 Aug. 2003, T. Miyazaki 308070 (KH); Kouchi Pref., Nakatosa Town, Yamauchi, 4 Oct. 2003, T. Miyazaki 0310028 (KH); Kouchi Pref., Kubokawa town, Moriga-Uchi Rindou, 9 Oct. 2003, T. Miyazaki 0310344, 0310157 (KH).
Cuspidata sieboldii: JAPAN. Honshu: Kyoto-fu, Kyoto-si, Kamigyo, Kyotogyeon 3 street, 8 Dec. 1987, T. Takagi 224 (KYO); Shiga Pref. Takashima-shi, Kamo, Kamo-gawa, 20 Aug. 1987, H.T. Im 22630 (KB). Kyushu: Kagoshima pref., Isl. Yaku-sima, 2 Sep. 1933, M. Tagawa 1947 (KYO). Shikoku: Kouchi Pref., Sukumo-shi, Okinoshima-cho, Isl. Okinoshima, 5 Sep. 2006, S. Fujii 12127 (KYO).
KOREA. Gyeongsangnam-do: Geoje-si, Jisim Island, 4 May. 1928, T. Nakai 10986, 10985 (TI); Tongyeong-si, Hansan-myeon, 23 Aug. 2010, G.Y. Chung Tongyeong-si(hansando)-100823-047 (KH); Tongyeong-si, Yokji-myeon, 24 Aug. 2010, G.Y. Chung Tongyeong-si(Yokjido)-100824-134 (KH). Jeollanam-do: Goheung-gun, Oenaro-do, 22 May 1928, T. Nakai 10983 (TI); Goheunggun, Bongnae-myeon, Yenae-ri, Is. Naro, 25 Sep. 2015, J.K. Ahn, KOSPVP0000350682 (KB); Goheung-gun, Bongnae-myeon, Oenaro-do, Changpo, Isl., 9 Aug. 2001, J.S. Sun JJ110988 (KH); Jindo-gun, Jodo-myeon, Is. Gwanmae, 07 Jul. 2016, H.T. Im OJFWVP2121 (KB); Jindo-gun, Jodo-myeon, Sinyuk-ri, Isl. Hajo-do, 7 Sep. 2011, S.Y. Jeong, HJK110056 (KH); Sinan-gun, Heuksan-myeon, Heuksan Island, 23 Aug. 1919, T. Ishidoya & T.H. Chung 3416 (TI); Sinan-gun, Heuksan-myeon, Hong Island, 27 Aug. 1919, T. Ishidoya & T.H. Chung 3419 (TI); Sinan-gun, Heuksan-myeon, Mt. Biri, 18 Aug. 2017, H.R. Jeong, Daejangdo(Biri)-170818-070 (KH); Sinan-gun, Heuksan-myeon, Hongdo-ri, 30 Sep. 2017, J.H. Lee, Hongdo-170930-123, Hongdo-170930-162 (KH); Sinan-gun, Heuksan-myeon, Is. Hataedo, 01 Sep. 2012, J.K. Ahn 5624 (KB); Sinan-gun, Heuksanmyeon, Gageodo-ri, Mt. Hoeryong, 13 Jul. 2011, J.H. Kim NIBRVP307937 (KB); Sinan-gun, Heuksan-myeon, Mt. Ye-ri, 9 Oct. 2017, S.Y. In Heuksando(yeri)-171009-008 (KH); Wando-gun, Gunoe-myeon, Daemun-ri san 190-1, Wando Arboretum, 29 Aug. 2009, J.H. Jung 200902&200931-79, 200913& 200917-96, 200916&200924-70 (KB); Wando-gun, Wando-eup, Mt. Obong, 02 Jul. 2011, K.W. Lee 201108-0047 (KB); Yeosu-si, Geomun Isalnd, 24 May 1928, T. Nakai 10984; Yeosu-si, Is. Bogil, 23 Jul. 1993, H.T. Im, KOSPVP208169 (KB). Jeju-do: Jeju Isalnd, Oct. 1906, U. Faurie 184 (TI); Jeju Isalnd, 17 Aug. 1912, T. Nakai 227, 242 (TI); Southern Jeju Isalnd, 3 Nov. 1917, T. Nakai 4908 (TI); Jeju Isalnd, Mt. Halla, 17 May 1913, T. Nakai 937, 242 (TI); Jeju Isalnd, northern, 30 Oct. 1917, T. Nakai 4906 (TI); Jeju Isalnd, southern, 2 Nov. 1917, T. Nakai 4906, 4907 (TI); Jejusi, Hangyeong-myeon, Cheongsu-ri, Cheongsu-Gotjawal, 12 Oct. 2012, D.S. Kim, HALLA1871 (KH); Jeju-si, Jocheon-eup, Dongbaek-ro, Dongback Dongsan, 3 Oct. 2023, E.D. Lee, Dongback Dongsan 231003-001 (KH); Jeju-si, Gujwa-eup, Pyeongdairi, 08. Aug. 2008, H.W. Kim 2008-0514 (KB); Jeju-si, Haean-dong, Mt. Halla youngsil~wisseoleum~eolimok, 8 Jul. 2005, K.J. Kim VP7400044038 (KB); Jeju-si, Hangyeong-myeon, Myeongi-dong, 21 Sep. 2006, S.H. Park, ParkSH62057 (KH); Seogwiposi, Hong-ro, 6 Jun. 1913, T. Nakai s.n. (TI); Seogwipo-si, Hong-ro, Oct. 1913, E.J. Taquet 6221, 6223 (TI); Southern Jeju Isalnd, 3 Nov. 1917, T. Nakai 4908 (TI); Seogwipo-si, Namwon-eup, Sillyecheon-ro, 3 Oct. 2023, E.D. Lee, Sillyecheon 202310-001, Sillyecheon 202310-002, Sillyecheon 202310-003 (KH); Seogwipo-si, Seogwng-ri, Gotjawal, 16 Oct. 2005, E.S. Jeon, ESJeon 53456 (KH); Seogwipo-si, Andeok-myon, 20 Jun. 1997, S.B. Yun, JNU 2476, JNU 2473(KB); Seogwipo-si, Cheonjiyeon, 14 Jul. 2007, Y.S. Kim KOSPVP107743 (KB).