(3012) Proposal to conserve the name Serissa against Buchozia (Rubiaceae)

(3012) Serissa Comm. ex Juss., Gen. Pl.: 209. 4 Aug 1789 [Rub.], nom. cons. prop.

Typus: S. foetida (L. f.) Poir. (in Lamarck, Tabl. Encycl. 2: 211. 31 Oct 1819) (Lycium foetidum L. f.).

(=) Buchozia L'Hér., Buchozia: ad t. [1]. Aug–Dec 1788, nom. rej. prop.

Typus: B. coprosmoides L'Hér., nom. illeg. (Lycium japonicum Thunb.; B. japonica (Thunb.) Callm.).

Serissa is a genus of one or perhaps two species naturally occurring in China, Japan, Nepal and Vietnam (Chen & Taylor in Wu & Raven, Fl. China 19: 323–324. 2011). Serissa japonica (Thunb.) Thunb. is very extensively cultivated worldwide as a bonsai subject, especially valued for its delicate branching, rough grey bark, numerous dainty flowers throughout the year and, in some cultivars, variegated foliage and/or “double” flowers. In China, Serissa has been cultivated as bonsai at least since 1591 in the Ming Dynasty (Gao, Eight Discourses on Respecting Life [in Chinese]. 1591). The earliest Japanese horticultural record dates back to 1695 (Ito Ihei, Book Glorious Colours Gardens [in Japanese]. 1695). In addition, the plant has been used in traditional Chinese medicine (e.g., for the treatment of ulcers and diarrhoea) for over 1200 years (Chen, Suppl. Materia Medica [in Chinese]. 739). Recent nomenclatural research (Lack & al. in Candollea 76: 145–165. 2021) has revealed that the generic name Buchozia is an earlier validly published name for the genus that is today universally known in horticulture as Serissa. Strict application of the principle of priority would necessitate the adoption of Buchozia. The overlooked name Buchozia has only very lately been unearthed whereas Serissa is a name used for over 230 years in both botanical and horticultural literature and is the Latin name used by bonsai enthusiasts, plant nurseries and E-commerce platforms.

Serissa was formally described by Jussieu (Gen. Pl.: 209. 1789) but ascribed to Philibert Commerson, who collected a cultivated S. japonica plant in an unknown locality (likely Mauritius). The etymology of the name may be derived from an Indian vernacular name: although Commerson never travelled to India, he botanised extensively in Mauritius where a substantial Indian population exists and may have brought the plant to Mauritius. Commerson might have used the name Serissa owing to its superficial resemblance to Carissa L. (Apocynaceae), which is based on the Sanskrit name corissa. Because the protologue includes a reference to “Lycio foetido LS.”, the type of the previously published name Lycium foetidum L. f. (Suppl. Pl.: 150. 1782) is definitely included. Therefore, the type of Serissa is the type of L. foetidum. Poiret (in Lamarck, Tabl. Encycl. 2: 211. 1819) subsequently made the new combination Serissa foetida (L. f.) Poir. In the protologue of Lycium foetidum, Linnaeus filius cited “Habitat in Japonia, Thunberg; in China, Thouin; in Madera, König” and “Thouin misit ilam nomine Spermacoces fruticosae Jussieui”. In the LINN herbarium, there are three specimens (collected by Thunberg, Thouin and Koenig) labelled Lycium foetidum in Linnaeus filius's hand. The specimen from China, no doubt from material sent to Thouin in Paris (see Letouzey, Jardin Plantes André Thouin 1747–1824: 100 etc. 1989) bears an annotation “Spermacoce fruticosa” in Thouin's hand, besides Linnaeus filius's label; it has well-developed leaves and stipules at many nodes and some flowers. The other two syntypes have only shrivelled, immature leaves at just a few nodes. Therefore, the Chinese specimen Thouin s.n. (LINN) is designated here as the lectotype of Lycium foetidum:

Lycium foetidum L. f., Suppl. Pl.: 150. 1782 ≡ Serissa foetida (L. f.) Poir. in Lamarck, Tabl. Encycl. 2: 211. 1819 – Lectotype (designated here): China, s.d., Thouin s.n., Herb. Linnaeus No. 259.10 (LINN).

Plants of the World Online (POWO; https://powo.science.kew.org/) includes 20 species records under the generic name Serissa, but 11 of these are currently recognised under Canthium Lam., Saprosma Blume or Villaria Rolfe (Rubiaceae). The number of true Serissa species is disputed: Ko (in Chen, Fl. Reipubl. Popularis Sin. 71: 159–162. 1999), Puff & al. (Rubiaceae Thailand: 232. 2005) and Chen & Taylor (l.c.) recognise two species (viz. S. japonica (Thunb.) Thunb. and S. serissoides (DC.) Druce) whereas POWO (l.c.) recognises only a single species (recently listed as Buchozia japonica (Thunb.) Callm., i.e., S. japonica).

Buchozia was published by L'Héritier (Buchozia: ad t. [1]. 1788) as the name for a monospecific new genus based on B. coprosmoides L'Hér., an illegitimate name that was nomenclaturally superfluous when published, because L'Héritier (l.c.) cited in synonymy Lycium japonicum Thunb. (in Nova Acta Regiae Soc. Sci. Upsal. 3: 207. 1780) and L. indicum Retz. (Observ. Bot. 2: 12. 1781), of which the former epithet should have been adopted as it has priority. Callmander (in Candollea 76: 162. 2021) recently made the new combination Buchozia japonica (Thunb.) Callm. and designated Thunberg s.n. (UPS-THUNB No. 5316) as the lectotype. Buchozia was published in 1788 (the year before the name Serissa), in an unpaginated leaflet. Although these L'Héritier's leaflets were listed in standard bibliographies (e.g., Pritzel, Thes. Lit. Bot.: 184. 1872; Stafleu & Cowan in Regnum Veg. 105: 3. 1981), these have very rarely been cited, such that the generic name Buchozia was never taken up. Indeed, Stafleu & Cowan (l.c. 94: 392. 1976), in their entry for Buchoz, held that the name was not validly published. Only with the recent analysis of L'Héritier's leaflets and copper engravings, of which only very few copies have survived worldwide (Lack & al., l.c.), has it been resurrected, contrary to citations in some older literature, where Buchozia appears merely as a synonym of Serissa (e.g., Candolle, Prodr. 4: 575. 1830; Don, Gen. Hist. 3: 633. 1834).

The currently accepted zoological name Buchozia (Bayan, Études Collect. École Mines 2: 113. 1873) (Mangeliidae), honouring Pierre-Joseph Buc'hoz, was adopted for a genus of extinct marine gastropods, but consideration of homonymy does not extend to zoological taxa (Art. 54.1 of the ICN; Turland & al. in Regnum Veg. 159. 2018). However, Buchozia, also commemorating Pierre-Joseph Buc'hoz, is very similar to four other plant generic names: (1) Bucholzia Mart. (Nov. Gen. Sp. Pl. Bras. 2: 49. 1826), commemorating Christian Friedrich Bucholz, a synonym of Alternanthera Forssk. (Amaranthaceae); (2) Bucholzia Stadtm. ex P. Willemet (in Ann. Bot. (Usteri) 18: 54. 1796), commemorating Pierre-Joseph Buc'hoz, a synonym of Combretum Loefl. (Combretaceae); (3) Buchholzia Engl. (in Bot. Jahrb. Syst. 7: 335. 1886), commemorating Reinhold Wilhelm Buchholz, a currently accepted generic name (Capparaceae); and (4) Buchosia Vell. (Fl. Flumin.: 33. 1829) (Pontederiaceae), also commemorating Pierre-Joseph Buc'hoz. Although all four postdate L'Héritier's name, the similar spelling may cause unnecessary confusion which can be avoided by acceptance of this proposal; indeed, Buchholzia (Capparaceae) has been rendered as Buchozia by Okoye & al. (in IOSR J. Appl. Chem. 7: 104–111. 2014).

The name Serissa has been in universal use since the early nineteenth century largely owing to its widespread cultivation as bonsai. Serissa is used in numerous publications and online sources, including nine guidebooks on bonsai (e.g., Ainsworth, Art Indoor Bonsai. 1988; Pike, Indoor Bonsai. 1989; Tomlinson, Complete Book Bonsai. 1990; Li, Cult. Hist. Chinese Bonsai [in Chinese]. 2005; Lewis, Bonsai Basics. 2008), at least two general horticultural guidebooks (Boo & al., Pl. Trop. Cities: 736. 2014; Soh & al., 1001 Gard. Pl. Singapore (Climbers, Shrubs & Groundcovers): 324. 2020), four plant and gardening dictionaries (Burkill, Dict. Econ. Prod. Malay Penins. 2: 2028. 1966; Bailey & al., Hortus Third: 1038. 1976; Huxley & al., New Roy. Hort. Soc. Dict. Gard.: 284. 1992; Mabberley, Mabberley's Plant-Book, ed. 4: 850. 2017), exhibition and competition catalogues (e.g., Singapore Penjing Society, 1st Singapore Penjing & Artistic Stone Exhibition Competition: 85. 1994), Materia Medica (e.g., Stuart, Chinese Mater. Med.: 404. 1911), 11 floristic accounts of Rubiaceae (e.g., Nazimuddin & Qaiser in Nasir & Ali, Fl. Pakistan 190: 92. 1989; H Càphê in H Phạm-hoàng, Câyco Viêtnam 3: 263. 1993; Yamazaki in Iwatsuki, Fl. Japan 3a: 228. 1993; Puff & al., l.c.; Chen & Taylor, l.c.) and two printed checklists (Press & al., Annot. Checkl. Fl. Pl. Nepal: 278. 2000; Chang & al., Provis. Checkl. Vasc. Pl. Korea Penins. Fl.: 567. 2014). On 3 October 2023, a search on the BGCI PlantSearch portal (https://tools.bgci.org/plant_search.php) yielded 17 named Serissa cultivars but none for Buchozia; a search on the image-hosting website Flickr revealed 1362 photos for Serissa, and only 11 photos for Buchozia; a search on the citizen science website for biodiversity observations iNaturalist (https://www.inaturalist.org/) retrieved 313 observations for Serissa but none for Buchozia; a search on the online marketplace for plants in Singapore SindoMall (https://www.sindomall.com/) revealed 122 products ranging from SGD 25 to SGD 1250 but none for Buchozia; a Google Scholar search for “Serissa Rubiaceae” produced 372 results, including papers on molecular phylogenetics, traditional Chinese medicine, ethnobotany, phytochemistry, palynology, karyology, ecology and horticulture, whereas a corresponding search for “Buchozia Rubiaceae” generated 5 results, of which one is the aforementioned misspelling of Buchholzia (Capparaceae); a Google search for “Serissa bonsai” resulted in 341,000 hits whereas a search for “Buchozia bonsai” resulted in 491 hits. The name Buchozia was only recently adopted by POWO (l.c.), the online Catalogue of the Plants of Madagascar (http://legacy.tropicos.org/Project/Madagascar) and the Kew Tree of Life Explorer (https://treeoflife.kew.org/), after the dating of Buchozia L'Hér. was clarified.

The global bonsai market size was estimated to be over USD 8 billion in 2022 and is expected to reach USD 15.8 billion in 2028 according to Business Research Insights (https://www.businessresearchinsights.com/). As one of the most popular indoor bonsai, the size of the Serissa business must therefore be large. In the interests of nomenclatural stability for end-users, we propose to conserve the widely used name Serissa over Buchozia for this horticulturally important plant.