(3115) Proposal to conserve the name <i>Cinnamomum cassia</i> Nees ex Blume against <i>C. cassia</i> (L.) J. Presl/D. Don (<i>Lauraceae</i>)

(3115) Cinnamomum cassia Nees ex Blume, Bijdr.: 570. 24 Jan 1826, nom. cons. prop. Lectotypus (hic designatus): cultivated in Java, Blume (L barcode L 0035701; isolectotypi: K barcode K000350934, L barcodes L 0035700, L 0035702, L 0035703, L 0035704 & L 0035705, NY barcode 00355005, S No. S-G-1377). (H) Cinnamomum cassia (L.) J. Presl, Přir. Rostlin 2: 44. [1823–]1825; D. Don, Prodr. Fl. Nepal.: 67. 26 Jan–1 Feb 1825 (Laurus cassia L., Sp. Pl.: 369. 1 May 1753), nom. rej. prop. Lectotypus (first-step, see Kostermans in Dassanayake & al., Rev. Handb. Fl. Ceylon 9: 164. 1995): “Hermann s.n. (BM)”; (second-step, see Chakrabarty in Phytotaxa 379: 275. 2018): Sri Lanka, Herb. Hermann 2: 67, No. 146 (BM barcode BM000621733 [image!]; isolectotypus: BM barcode BM000621734 [image!]). Epitypus (see Chakrabarty in Phytotaxa 379: 275. 2018): Sri Lanka, above Belihuloya, 10 May 1969, Kostermans 23429 (L No. 322834 [2D-code L.1802766] [image!]). Cassia, also known as Chinese cassia or cassia cinnamon, is commonly marketed and referenced in the literature under the scientific name Cinnamomum cassia (attributed to various authors). It is the second most widely known and traded species of cinnamon worldwide, surpassed only by C. verum J. Presl (Prir. Rostlin 2: 37–44. 1825), formerly known as C. zeylanicum Garcin ex Blume (Bijdr.: 568. 1826), also known as the true cinnamon. The epithet “cassia” derives from the Greek word kassia (κασία), which in turn originates from the Hebrew qətsīʿāh (קְצִיעָה), meaning “fragrant bark”. This etymology may have contributed to longstanding taxonomic confusion and mixing of material, as many species within the genus Cinnamomum Schaeff. and closely related genera possess characteristically fragrant bark. Linnaeus (Sp. Pl.: 369. 1753) described a species, native from India to Malaysia and Sri Lanka, naming it Laurus cassia L. Later, in 1825, Linnaeus's name was combined twice, resulting in Cinnamomum cassia (L.) J. Presl (Prir. Rostlin 2: 44. [1823–]1825), the precise date of publication of which is unknown, and C. cassia (L.) D. Don (Prodr. Fl. Nepal.: 67. 26 Jan–1 Feb 1825). More recently, a new combination based on Linnaeus's basionym was proposed, leading to the name Neolitsea cassia (L.) Kosterm. (in J. Sci. Res. (Jakarta) 1: 85. 1952), which is now the accepted name for the basionym Laurus cassia, as clearly noted by Chakrabarty (in Phytotaxa 379: 274–276. 2018). Chakrabarty also highlights the mixture of species among the original materials cited by Linnaeus in the protologue of L. cassia, which contributed to the divergent interpretations. Some floras and databases still use the name C. cassia, as a combination from L. cassia, to refer to cassia cinnamon, cassia, or Chinese cassia, as seen in the Flora of China (Li & al. in Wu & al., Fl. China 7: 186. 2008). Blume (l.c.: 529) treated Lauraceae “op eene, in de jaren 1823–1824 gedane reis over Java, waargenomen en beschreven” (observed and described on a journey made in the years 1823–1824 over Java), including the name “Cinnamomum cassia Nees ab Esenb.”, presumably in reference to the concept of Nees & Nees (Cinnam. Disp.: 53, t. 3. 1823), rather than that of Linnaeus. Although Nees & Nees (l.c.: 53) used the name Laurus cassia L., in a key they (l.c.: 48) had associated “Lauri species cinnamomiferae” (cinnamomiferous species of Laurus) with the genus Cinnamomum. However, their description and illustration clearly refer to a different plant from that of Linnaeus, as can be deduced from morphological analysis. This confusion may be rooted in the mixed material referenced by Linnaeus in the protologue of L. cassia. Cinnamomum cassia Nees ex Blume (l.c.: 570) was the first homonym published based on material of cassia cinnamon, a species widely cultivated and traded around the world. In addition to the indirect reference to Nees & Nees's (l.c.) Cinnamomum description and illustration, Blume's protologue for C. cassia states, “crescit: ex China introductum” (grows: introduced from China). This refers to cultivated material he personally collected and studied in Java, which was later sent to the Herbarium Lugduno-Batavorum (now L) and distributed elsewhere from there. The specimens involved are therefore syntypes, which in lectotype designation (ICN Art. 9.12; Turland & al. in Regnum Veg. 162. 2025) take precedence over the illustration of Nees & Nees (l.c.: t. 3) that would also be original material. One of these syntypes (L barcode L 0035701) is here designated as lectotype. Unfortunately, Blume's name was published the year after both Presl (l.c.) and Don (l.c.) had already combined Laurus cassia into the genus Cinnamomum, making Blume's heterotypic name an illegitimate later homonym. Currently, the earliest available name for this species is C. aromaticum Nees (Pl. Asiat. Rar. 2: 74. 1831). However, this name is less recognized or used in reference to cassia cinnamon, either in scientific literature or commerce. As an example, while the name C. aromaticum appears in the title of 24 articles indexed in Google Scholar from the last 50 years, C. cassia occurs in 1080 titles over the same period. Beyond its economic importance as a globally traded commodity and household staple, the species carries public health implications. Introducing a new name like Cinnamomum aromaticum Nees would be incredibly risky. Consumers have learned to associate the name C. cassia with its coumarin content and the potential for dangerous herb-drug interactions, especially with blood thinners. A name change would confuse everyday consumers, leaving them unaware of the new name and its relationship to critical coumarin levels. This lack of awareness could have severe consequences for individuals on blood thinners, who rely on clear labeling for their safety. The established name, C. cassia, is a direct link to consumer awareness and crucial safety information. In accordance with Art. 14, we here propose conservation of Cinnamomum cassia Nees ex Blume against its earlier homonym C. cassia (L.) J. Presl or D. Don. This will prevent the loss of the widely recognized and culturally significant name C. cassia, which is used globally for the species known as cassia cinnamon, cassia, or Chinese cassia on commercial products, in daily life, and in association with traditional knowledge, including folk medicine, traditional Chinese medicine, herbal remedies, culinary spices, and dietary supplements. This conservation would do more than just preserve a name. It would secure the clarity of a vital global commodity, protect centuries of traditional knowledge, prevent widespread confusion, and most importantly, ensure the safety of the average consumer. The continued use of this widely recognized name is crucial for maintaining order, accurate identification, and the safe use of this cherished spice.