(3138) Proposal to conserve the name <i>Clerodendrum nutans</i> ( <i>Lamiaceae</i> ) with a conserved type

(3138) Clerodendrum nutans Wall. ex Jack in Malayan Misc. 1(1): 17. 1820 [Angiosp.: Verben. / Lab.], nom. cons. prop. Typus: [Malaysia,] Penang, base of Penang Hill, Mar 1896, Ridley 7181 (K barcode K000249210; isotypus: SING barcode 0094508), typ. cons. prop. Jack (in Malayan Misc. 1(1): 17. 1820) described the species Clerodendrum nutans whilst ascribing the name to Wallich and suggesting it occurs both in Bengal (India or Bangladesh) and in Penang (Malaysia). It is likely he based his description on his own collections from Penang (Merrill in J. Arnold Arbor. 33: 219. 1952). Don (Prodr. Fl. Nepal.: 103. 1825) also described C. nutans, citing Wallich's designation, but applied the concept only to the material from Bengal. Various authors have since concluded that the material from Bengal and the material from Penang represent two different species, beginning with Wallich himself (in Bot. Mag. 58: t. 3049. 1831), who said the Penang material should go by the name of C. jackianum Wall. (Numer. List: No. 1794. 1829), which he had already published as a nomen novum for C. nutans despite associating the name with a specimen of the different species C. disparifolium Blume (Bijdr.: 809. 1826). Clerodendrum jackianum is therefore an illegitimate homotypic synonym of C. nutans. Merrill (l.c.: 220) discussed the confusion that had arisen due to Jack's inclusion of disparate elements in Clerodendrum nutans, compounded by later attempts to rectify the problem (also see discussion by Wearn & Mabberley in Syst. Bot. 36: 1053. 2011). Merrill noted that the name C. nutans should only apply to the species as found in Penang and the immediate region and that this meant the Bengal material lacked a name. His solution was to give the Bengal material, under no. 1793 in the herbarium of the East India Company (also known as the Wallich Herbarium) and as described by Don (l.c.), the name C. wallichii Merr. He did not, however, formally typify the name C. nutans with material from Penang or elsewhere in Southeast Asia, only noting a poor Korthals specimen from Sumatra as likely to be a specimen of the species. Wearn & Mabberley (l.c.) noted that C. wallichii from Bengal did also occur in Southeast Asia and agreed with earlier authors, although with caveats due to several misapplications, that C. wallichii should be treated as a synonym of C. laevifolium Blume (l.c.: 808). In Bramley & al. (Fl. Males., ser. 1, 23: 126. 2019), the type of Clerodendrum wallichii is given as “Wallich s.n. in Wallich Cat. 1793.1 (holo K-W; iso BM)”, a reference to a specimen in Kew, collected by De Silva from Sylhet (formerly part of Bengal but now in Bangladesh), with the barcode K001114199. However, Merrill specified only “List no. 1793” when he described the species and there are at least two collections under this number amongst the material referred to “Clerodendrum nutans” by Wallich (see https://wallich.rbge.org.uk/index.php?section=entries&id=1793). There is consequently no holotype and it would appear that the name has not been lectotypified. To rectify this, the specimen from Kew mentioned above, K barcode K001114199, is here designated as lectotype of Clerodendrum wallichii Merr. In various works (Wearn & Mabberley, l.c.: 1052; Bramley & al., l.c.: 138), authors have given the type of Clerodendrum nutans Wall. ex Jack as “Jack, Penang, holotype not found” or words to that effect. However, as Jack made no distinction between the Bengal and Penang material he included in his concept of the species, there is no holotype. Instead, a lectotype could be chosen from amongst the original material, comprising specimens from Bengal identified by Wallich as this species before it was formally described by Jack, and Jack's own collection(s) from Penang. Wallich's Bengal material comprises specimens from the East India Company Herbarium, number 1793, of which there are several specimens from more than one gathering. Jack's specimens from Penang were mostly lost in a fire (Merrill, l.c.: 199–251) and no material that Jack could have used for the protologue has been found. This means that the only extant original material for C. nutans are the specimens from the East India Company Herbarium no. 1793, which have since been used to describe C. wallichii Merr. None of the extant original material represents C. nutans as understood today. Under ICN Art. 9.8 (Turland & al. in Regnum Veg. 162. 2025) a neotype can only be chosen if there is no extant original material. This article does not apply to Clerodendrum nutans as there is extant original material. Under Art. 9.16, if a previously designated lectotype is lost and all other original material differs taxonomically, a neotype could be designated to preserve the usage. We have not found a lectotypification of the name nor a reference to the use of “holotype” or “type” for an unseen Jack specimen in a publication before 2001 (Art. 7.11) that would have effected a lectotypification and would now allow a neotypification. The removal of all of the original material from C. nutans except for Jack's hypothetical material from Penang also does not effect a typification of the name. The simplest solution would be to designate a specimen as a neotype for C. nutans but this is not allowed under the rules. Therefore, conservation of the name with a conserved type, a specimen collected by Ridley in 1896 from Penang Island (K barcode K000249210), is here proposed. If the proposal is not accepted and the name is typified by a specimen under the East India Company Herbarium no. 1793, then Clerodendrum nutans Jack (l.c.) would become the correct name for the species currently called C. laevifolium Blume (l.c.: 808) and C. penduliflorum Wall. ex Schauer (in Candolle, Prodr. 11: 664. 1847), a heterotypic synonym of the species currently called C. nutans, would become the correct name for this species. We thank John McNeill (E) and Gemma Bramley (K) for useful discussions and Bazilah Ibrahim (SING) for information on specimens.