(3044) Proposal to reject the name Bubon rigidius (Umbelliferae)

(3044) Bubon rigidius L., Sp. Pl.: 254. 1 Mai 1753 [Angiosp.: Umbell.], nom. utique rej. prop. Typus: non designatus. Linnaeus (Sp. Pl.: 253–254. 1753) published at the rank of species four names in the genus Bubon L. (Apiaceae) (B. galbanum, B. gummiferum, B. macedonicum, B. rigidius). Three of these species are currently placed in other genera (i.e., Peucedanum galbanum (L.) Benth. & Hook. f., P. gummiferum (L.) Wijnands, Athamanta macedonica (L.) Spreng.) (see Jarvis, Order out of Chaos: 364. 2007). Linnaeus (l.c. 1753: 254) described Bubon rigidius providing a short diagnosis "BUBON foliolis linearibus" quoted from an earlier work by Linnaeus (Hort. Cliff.: 95. 1737) and Royen (Fl. Leyd. Prodr.: 100. 1740), followed by a synonym: "Ferula durior s. rigidis & brevissimis foliis" cited from Boccone (Mus. Piante Rare Sicilia: 84, t. 76. 1697) and Barrelier (Pl. Galliam: 61, t. 77. 1714). The protologue also includes information about the origin of the species, "Habitat in Sicilia". The references quoted by Linnaeus (Boccone, l.c.; Barrelier, l.c.) include illustrations that can be considered as original material. Boccone's drawing "Ferula durior, seu rigidis et brevissimis foliis" (l.c.: t. 76) illustrates a complete plant, with leaves and fruits, and a detail of three fruits. The illustration published by Barrelier (l.c.: t. 77) represents a mirror image of Boccone's drawing. Either of these two illustrations would be eligible as the lectotype of the name and they match the Linnaean diagnosis ("foliolis linearibus"). There is a relevant herbarium sheet in the Clifford Herbarium at BM. The specimen Herb. Clifford: 95, Bubon 1 (barcode BM000558276) bears an immature plant, with leaves and flowers, but no fruits, and it is annotated "Ferula | durior, seu ri- | gidis et bre- | vissimis foliis | Bubon rigidius" and "p. 95. Bubon. 1" at the base of the sheet (https://data.nhm.ac.uk/object/d3335d88-8d4c-445b-bcfa-26e5707dce7b/1713657600000). This specimen is incomplete (lacks diagnostic features relevant for the Apiaceae, such as the fruits). Unfortunately, we have not been able to locate any further original material in any Linnaean and Linnaean-linked herbaria. The identity of Bubon rigidius has never been clarified and the application of the name is uncertain. Unfortunately, the protologue published by Linnaeus does not provide sufficient information for a precise identification, and the taxonomic identification of the immature and incomplete original specimen BM000558276 is very complicated. In addition, the interpretation of Barrelier's and Boccone's illustrations seems ambiguous. Gussone (Fl. Sicul. Prodr. 1: 366. 1827), although citing Ferula rigida Ten. in synonymy in the protologue of F. geniculata Guss., made clear that he was excluding Tenore's synonym, Bubon rigidius. Gussone (l.c. 1827) included Boccone's illustration albeit with a question mark. Fifteen years later Gussone (Fl. Sicul. Syn. 1: 355. 1842) in the account of his Ferulago geniculata (Guss.) Guss. added some other synonyms but retained his exclusion of the Linnaean binomial from Ferula rigida Ten. and referred Barrelier's and Boccone's illustrations to Prangos ferulacea (L.) Lindl. (in Quart. J. Sci. Lit. Arts 19: 7. 1825, based on Laserpitium ferulaceum L., Sp. Pl., ed. 2: 358. 1762) ("Non immerito Cl. Bertol. in fl. ital. 3. p. 379 icones Bocc. et Barr. ab hac specie excludendas esse notat, siquidem quoad habitum magis Prangos ferulaceam referunt, sub qua inde citavi" (Not undeservedly the famous Bertoloni in Fl. Ital. 3: 379 [1837] notes that the images of Boccone and Barrelier are to be excluded from this species, since in regard to their habit they refer rather to Prangos ferulacea, under which hence I have cited them) (see also Bertoloni [l.c.] on Ferula geniculata Guss.: "Figura Ponae superius allata bona, licet rudis, nec ullo pacto dubia; sed dubia profecto est Ferula durior seu rigidis et brevissimis foliis Barrel. Ic. 77. Bocc. Mus. di piant. tab. 76., cum caulis in hac careat geniculis tumentibus, et sit foliatus ab imo ad summum" – The figure of Pona mentioned above, although crude, is not in any way doubtful; but Ferula durior seu rigidis et brevissimis foliis Barrel. Ic. 77. Bocc. Mus. di piant. tab. 76 is certainly doubtful because the stems in this one lack the swollen nodes, and are foliated from the bottom to the top). Jarvis & al. (in Taxon 55: 207. 2006) wrote "we have unfortunately been unable to persuade any specialist to make a type choice". POWO (2024, see http://www.plantsoftheworldonline.org/) considers Bubon rigidius a synonym of Ferula communis L. (l.c. 1753: 246), but other relevant databases (e.g., Euro+Med PlantBase, WFO Plant List, Tropicos.org) do not include it. A way to clarify the identity of Linnaeus's Bubon rigidius could be to select a lectotype and then epitypify the name. In this sense, according to the fruits (mericarps) being narrowly elliptical to narrowly oblong-obovate as shown in Boccone's and Barrelier's illustrations and the features preserved in the specimen BM000558276 (e.g., leaves 2- to 3-ternate, with lobes linear, narrowed at the ends, flat or with margins slightly recurved, with prominent midrib and weaker marginal veins, rays 5–10, bracts 5–10, bracteoles several, petals yellow), an epitype based on a specimen belonging to the genus Prangos, Cachrys, Ferulago or Peucedanum would not be in conflict with the Linnaean protologue, and thus would need to be accepted. However, depending on the specimen chosen as epitype, Bubon rigidius could then become a name disruptive to nomenclatural stability. Consequently, we consider this name a candidate for formal rejection. We believe it is appropriate to point out that it seems somewhat paradoxical to treat a name with at least three original materials (a specimen and two illustrations) as ambiguous, since this material must belong to a currently known species. Which species did Linnaeus want to describe? Despite the claim in POWO, it is unlikely that he described twice what is now known as Ferula communis, published in the same work as Bubon rigidius. Moreover, Ferula communis is a species very well known to the authors of this proposal, and does not correspond to any of Linnaeus's original elements (illustrations of Boccone and Barrelier, and the specimen BM000558276). Therefore, we believe that a suitable solution, better than designating an epitype without objective basis, is to reject the name Bubon rigidius in accordance with Art. 56 of the ICN (Turland & al. in Regnum Veg. 159. 2018). Acceptance of this proposal would neutralise any possible threat posed by B. rigidius to other names that would not have priority, as Prangos ferulacea (see Bertoloni, l.c.; Gussone, l.c. 1842) or Ferula geniculata (see Troia & al. in Pl. Biosyst. 146(Suppl.): 336. 2012; Bartolucci & al. in Phytotaxa 196: 80. 2015). However, rejection of this proposal would permit the resurrection of Bubon rigidius, an obscure name not used for more than two centuries. Thanks to Dr. John McNeill and Dr. John Wiersema for their advice, assistance, and valuable comments that improved this proposal.