Taxonomic reassessment and typification of species names in Arctotis L. (Asteraceae) proposed by Jean Louis Marie Poiret

2019 ● 41 ● 14 adansonia Adansonia est une revue en flux continu publiée par les Publications scientifiques du Muséum, Paris Adansonia is a fast track journal published by the Museum Science Press, Paris Les Publications scientifiques du Muséum publient aussi / The Museum Science Press also publish: Geodiversitas, Zoosystema, Anthropozoologica, European Journal of Taxonomy, Naturae, Cryptogamie sous-sections Algologie, Bryologie, Mycologie. Diffusion – Publications scientifiques Muséum national d’Histoire naturelle CP 41 – 57 rue Cuvier F-75231 Paris cedex 05 (France) Tél. : 33 (0)1 40 79 48 05 / Fax : 33 (0)1 40 79 38 40 [email protected] / http://sciencepress.mnhn.fr © Publications scientifiques du Muséum national d’Histoire naturelle, Paris, 2019 ISSN (imprimé / print) : 1280-8571/ ISSN (électronique / electronic) : 1639-4798 Directeur De la publication : Bruno David Président du Muséum national d’Histoire naturelle réDacteur en chef / Editor-in-chiEf : Thierry Deroin réDacteurs / Editors : Porter P. Lowry II ; Zachary S. Rogers assistants De réDaction / AssistAnt Editors : Emmanuel Côtez ([email protected]) Mise en page / PAgE lAyout : Emmanuel Côtez coMité scientifique / sciEntific boArd : P. Baas (Nationaal Herbarium Nederland, Wageningen) F. Blasco (CNRS, Toulouse) M. W. Callmander (Conservatoire et Jardin botaniques de la Ville de Genève) J. A. Doyle (University of California, Davis) P. K. Endress (Institute of Systematic Botany, Zürich) P. Feldmann (Cirad, Montpellier) L. Gautier (Conservatoire et Jardins botaniques de la Ville de Genève) F. Ghahremaninejad (Kharazmi University, Téhéran) K. Iwatsuki (Museum of Nature and Human Activities, Hyogo) K. Kubitzki (Institut für Allgemeine Botanik, Hamburg) J.-Y. Lesouef (Conservatoire botanique de Brest) P. Morat (Muséum national d’Histoire naturelle, Paris) J. Munzinger (Institut de Recherche pour le Développement, Montpellier) S. E. Rakotoarisoa (Millenium Seed Bank, Royal Botanic Gardens Kew, Madagascar Conservation Centre, Antananarivo) É. A. Rakotobe (Centre d’Applications des Recherches pharmaceutiques, Antananarivo) P. H. Raven (Missouri Botanical Garden, St. Louis) G. Tohmé (Conseil national de la Recherche scientifique Liban, Beyrouth) J. G. West (Australian National Herbarium, Canberra) J. R. Wood (Oxford) couverture / covEr : Lectotype of Calendula graminifolia L. (Commelin 1701: 67, f. 34). Adansonia est indexé dans / Adansonia is indexed in: – Science Citation Index Expanded (SciSearch®) – ISI Alerting Services® – Current Contents® / Agriculture, Biology, and Environmental Sciences® – Scopus® Adansonia est distribué en version électronique par / Adansonia is distributed electronically by: – BioOne® (http://www.bioone.org) 183 ADANSONIA, sér. 3 • 2019 • 41 (14) © Publications scientifiques du Muséum national d’Histoire naturelle, Paris. www.adansonia.com KEY WORDS South Africa, Anthemideae, Arctotis, Calenduleae, Poiret, new lectotypes, new neotype, new synonym. McKenzie R. J. & Nepi C. 2019. — Taxonomic reassessment and typification of species names in Arctotis L. (Asteraceae) proposed by Jean Louis Marie Poiret. Adansonia, sér. 3, 41 (14): 183-192. https://doi.org/10.5252/adansonia2019v41a14. http://adansonia.com/41/14 ABSTRACT The names Arctotis staticifolia Poir. and Arctotis tenuifolia Poir. were validly published by Jean Louis Marie Poiret based on material collected from “Cap de Bonne-Espérance” and stated to be lodged in the Herbier Desfontaines. No original material for Arctotis staticifolia has been traced. The protologue is inconsistent with any known Arctotis L. species and previous treatment of A. staticifolia as a synonym of Gazania linearis (Thunb.) Druce var. linearis is not supported. The protologue for Arctotis staticifolia is most consistent with a narrow-leaved taxon of Dimorphotheca Vaill. ex Moench and specifically D. nudicaulis (L.) DC. var. graminifolia (L.) Harv. A neotype for Arctotis staticifolia is designated consistent with our interpretation and the name is formally placed in the synonymy of Dimorphotheca nudicaulis var. graminifolia. Arctotis tenuifolia Poir. has previously been treated as a synonym of Dimorphotheca nudicaulis var. graminifolia. Original material was located and the name Arctotis tenuifolia Poir. is here lectotypified and is placed in the synonymy of Ursinia tenuifolia (L.) Poir. subsp. tenuifolia. Arctotis tenuifolia Poir. is a later heterotypic homonym of Arctotis tenuifolia L. and is therefore nomenclaturally illegitimate. A lectotype is designated for Sphenogyne tenuifolia (L.) DC. var. heterochroma Harv., a synonym of Ursinia tenuifolia subsp. tenuifolia. Robert J. MCKENZIE Department of Plant Sciences and Afromontane Research Unit, University of the Free State, Phuthaditjhaba (South Africa) http://orcid.org/0000-0001-7054-3308 [email protected] Chiara NEPI Museo di Storia Naturale-Botanica, Università di Firenze, Via La Pira 4, 50121, Firenze (Italy) [email protected] Submitted on 5 February 2019 | accepted on 24 June 2019 | published on 21 November 2019 Taxonomic reassessment and typification of species names in Arctotis L. (Asteraceae) proposed by Jean Louis Marie Poiret 184 ADANSONIA, sér. 3 • 2019 • 41 (14) McKenzie R. J. & Nepi C. INTRODUCTION The genus Arctotis L. was established by Linnaeus (1753). In subsequent generic treatments by Linnaeus and other authors, diverse species were described as members of Arctotis. With refinement of the genus concept and description of additional genera, numerous names in Arctotis were subsequently determined to apply to elements of other genera, including Arctotheca J.C.Wendl., Cymbonotus Cass. and Haplocarpha Less. (members of the tribe Arctotideae, subtribe Arctotidinae as for Arctotis), and also Dimorphotheca Vaill. ex Moench (tribe Calenduleae), Gazania Gaertn. (tribe Arctotideae, subtribe Gorteriinae), and Ursinia Gaertn. (tribe Anthemideae). For a number of these taxa, the epithet of the name in Arctotis is the earliest legitimate epithet for the taxon at species rank. As part of an ongoing taxonomic and nomenclatural revision of the subtribe Arctotidinae, the identity of all validly published names applicable to taxa within the subtribe requires reassessment. Considerable progress has been made in resolving the species taxonomy of Arctotidinae (e.g., McKenzie et al. 2008a, b, 2011; McKenzie & Barker 2010, 2013; McKenzie 2018, 2019; McKenzie & Bergh 2018). Reappraisal of Arctotis names known to apply to taxa now classified in Dimorphotheca, Gazania and Ursinia is not a primary focus of the current revision of Arctotidinae, as the latter three genera have been thoroughly revised previously (Norlindh 1943; Roessler 1959; Prassler 1967). However, during the course of the present revision, a number of validly published names in Arctotis of previously uncertain application have been determined to apply to taxa classified outside the Arctotidinae. In the present study, the identity and taxonomic status of the names Arctotis staticifolia Poir. and Arctotis tenuifolia Poir. validly published by Poiret (1810) were assessed. Arctotis staticifolia and A. tenuifolia Poir. were based on material stated to have been collected from “Cap de BonneMOTS CLÉS Afrique du Sud, Anthemideae, Arctotis, Calenduleae, Poiret, lectotypes nouveaux, néotype nouveau, synonyme nouveau. RÉSUMÉ Réévaluation taxonomique et typification des noms d’espèces chez Arctotis L. (Asteraceae) proposés par Jean Louis Marie Poiret. Les noms Arctotis staticifolia Poir. et Arctotis tenuifolia Poir. ont été publiés validement par Jean Louis Marie Poiret, à partir de matériaux rassemblés au « Cap de Bonne-Espérance » et déclarés être présents dans l’Herbier Desfontaines. Aucun matériel original n’a cependant été retrouvé pour Arctotis staticifolia. Le protologue est incompatible avec toute espèce connue d’Arctotis L. et le traitement antérieur de A. staticifolia comme synonyme de Gazania linearis (Thunb.) Druce var. linearis n’est pas valide. Le protologue de Arctotis staticifolia est plutôt compatible avec un taxon à feuilles étroites tel que Dimorphotheca Vaill. ex Moench et plus spécifiquement D. nudicaulis (L.) DC. var. graminifolia (L.) Harv. Un néotype pour Arctotis staticifolia est désigné, conformément à notre interprétation, et le nom est officiellement placé en synonymie avec Dimorphotheca nudicaulis var. graminifolia. Arctotis tenuifolia Poir. était auparavant considéré comme un synonyme de Dimorphotheca nudicaulis var. graminifolia. Le matériel original a été trouvé, le nom Arctotis tenuifolia Poir. est ici lectotypifié et considéré comme un synonyme de Ursinia tenuifolia (L.) Poir. subsp. tenuifolia. Arctotis tenuifolia Poir. est un homonyme hétérotypique ultérieur de Arctotis tenuifolia L. et est donc illégitime nomenclaturalement. Un lectotype est désigné pour Sphenogyne tenuifolia (L.) DC. var. heterochroma Harv., synonyme d’Ursinia tenuifolia subsp. tenuifolia. Espérance” [Cape of Good Hope] and lodged in the Herbier Desfontaines (Poiret 1810). Arctotis tenuifolia Poir. was included in the synonymy of Castalis nudicaulis var. graminifolia (L.) Harv. by Norlindh (1943), but the name has not been lectotypified. Norlindh stated that he did not examine original material for the name and his treatment of Arctotis tenuifolia Poir. followed that of Candolle (1838). The name Arctotis staticifolia was listed under Gazania ’Species dubia’ by Roessler (1959), and remains unresolved and untypified, but is often listed as a synonym of Gazania linearis (Thunb.) Druce var. linearis in online nomenclator databases. Typification and clarification of the application of validly published names is essential for the treatment of Asteraceae in the eFlora of South Africa project (Le Roux et al. 2017). Therefore, the objective of the present study was to locate and examine original material and reassess application of the names Arctotis staticifolia and A. tenuifolia Poir. MATERIAL AND METHODS Original material for Arctotis tenuifolia Poir. lodged in FI was located and examined. High-resolution digital images of the lectotype for Arctotis tenuifolia L. in LINN and specimens of Dimorphotheca nudicaulis var. graminifolia in P were examined. Relevant material lodged in NBG was examined. Herbarium acronyms follow Thiers (2019). All relevant literature was consulted. RESULTS AND DISCUSSION Arctotis stAticifoliA Poir. Poiret (1810) published the name ’Arctotis staticefolia’. The word ’statice’, a genus name published by Linnaeus (1753) but now in use only as a vernacular name for species of Li- 185 Typification of Arctotis species of Poiret ADANSONIA, sér. 3 • 2019 • 41 (14) fig. 1. — Lectotype of Calendula graminifolia L. (Commelin 1701: 67, f. 34). Image from the Biodiversity Heritage Library. Digitized by Missouri Botanical Garden, Peter H. Raven Library (https://www.biodiversitylibrary.org). 186 ADANSONIA, sér. 3 • 2019 • 41 (14) McKenzie R. J. & Nepi C. monium Mill. (Plumbaginaceae), is derived from the Greek statikē, feminine of στατικός (statikós), meaning ’static, causing to stand still, astringent’. Under the International Code of Nomenclature for algae, fungi, and plants (ICN; Turland et al. 2018) Art. 60.10, correct compounding of the elements ’statice’ and ’folia’ requires removal of the case ending of the transcribed Greek -ós and addition of the connecting vowel -i-. Under the provisions of ICN Arts. 60.10 and 61.4, the epithet ’staticefolia’ is correctable to ’staticifolia’ without a change in the attributed authorship of the name. Poiret (1810) stated that the species was described from material in the Herbier Desfontaines collected from Cap de Bonne-Espérance. No specimen formerly in the general herbarium of Desfontaines, nor material that can be linked to Desfontaines in other herbaria, and annotated with the name “Arctotis staticefolia” has been traced in BM, B-W, C, FI, LIV, MPU or P (based on the herbaria holding specimens linked to Desfontaines listed by Stafleu & Cowan 1976). Furthermore, no sheet of any origin annotated with the name has been traced in any herbarium. In the absence of original material, the affinities of Arctotis staticifolia must be determined from the protologue for the species. Poiret (1810) provided the diagnosis “Arctotis acaulis, foliis caespitosis, angustissimis, subintegris, glabris; foliolis calicinis lineari-lanceolatis; flore solitario” accompanied by a description of the growth habit, leaf morphology, involucre and floret colouration for A. staticifolia. A diagnostic character for Arctotis is that the cypselae bear two or three (rarely five) dorsal wings that are fused at the distal and proximal ends to create two or three distinct ’cavities’ or furrows on the dorsal side of the cypsela. Unfortunately, Poiret was unable to examine cypselae of Arctotis staticifolia, but from the description of the involucre A. staticifolia can be discounted as a species of Arctotis. The involucre of Arctotis is multiseriate and the individual bracts strongly differ in length from the shortest outermost bracts to the longest inner bracts, and in shape from triangular-ovate outer bracts to oblong-obovate inner bracts. The outer involucral bracts often have a short linear or obovate apical appendage and the inner bracts have a papery, translucent or red-pigmented apex. The bracts may be glabrous, glandular or sparsely to densely tomentose. Poiret’s description of the involucre of Arctotis staticifolia (“Cette plante est remarquable par son calice, composé d’un grand nombre de folioles étroites, oblongues, linéaires-lancéolées, aiguës, légèrement pileuses”) refers to the involucral bracts as many in number, narrow, oblong, and linear-lanceolate in shape, with an acute apex, and slightly hairy. This description is incompatible with the involucre of an Arctotis species. Application of the name Arctotis staticifolia by previous authors has varied. Candolle (1838) listed the name Arctotis staticifolia as a synonym of Gazania subulata R.Br. without commenting on the reason for the decision. In the most recent revision of Gazania, Roessler (1959) listed the name under Gazania ’Species dubiae’. Roessler noted Candolle’s treatment of Arctotis staticifolia and stated that he was unable to examine the type and therefore could not assess the affinities of the species. Roessler classified Gazania subulata as a synonym of G. linearis var. linearis. Arctotis staticifolia was not mentioned in treatments of the Asteraceae by Lessing (1832) or Harvey (1865), nor in the most recent monographs of Arctotis (Beauverd 1915; Lewin 1922). Online plant taxonomic databases (e.g., Catalogue of Life, http:// www.catalogueoflife.org/; Global Biodiversity Information Facility [GBIF], https://www.gbif.org; Global Compositae Checklist, https://compositae.landcareresearch.co.nz; The Plant List, http://www.theplantlist.org) presently list Arctotis staticifolia as a synonym of Gazania linearis var. linearis. Poiret’s description of the growth habit and the leaf morphology and arrangement are not inconsistent with those of Gazania linearis var. linearis. The leaves of A. staticifolia were described as numerous, gathered at the turf and all radical, very narrow, 5-7.5 cm or more long, scarcely broadened along the longitudinal axis, obtuse, entire, glabrous, entire but sometimes the margin was furnished with a few small distant teeth. However, Poiret described the floret colouration as “Les fleurons du centre sont d’un jaune-pâle, de couleur brune à leur sommet ; les demi-fleurons lancéolés, obtus, à trois dents, blancs en dehors, avec une teinte purpurine vers leur base, d’un jaune-clair en dessous” [The disc florets of the centre are of a pale yellow, the colour brown at their summit; the ray florets lanceolate, obtuse, with three teeth, white on exterior, with a purplish hue towards their base, light yellow underneath]. In Gazania linearis the disc-floret corolla and upper surface of the ray-floret limb are uniformly and consistently bright yellow. Among other Gazania species, in G. jurineifolia DC. the ray-floret limb is white above but streaked blackish brown below, and the disc floret corolla is yellow but with or without white apices to the lobes. In addition, the leaves of Gazania jurineifolia do not conform to Poiret’s description of the leaves of Arctotis staticifolia. If Poiret was describing a specimen of a Gazania species, it is remarkable that he would not note and comment on the fusion of the base of the involucral bracts to form a connate ’cup’ or ’cylinder’, which is such a distinctive and conspicuous characteristic of Gazania. Notably, in a subsequent brief discussion of the genus Gazania, Poiret (1811: 712) described the involucre of that genus as “Un calice d’une seule pièce, ventru à sa base, environné d’écaillés imbriquées, aiguës”. Therefore, Poiret’s description of Arctotis staticifolia is incompatible with a Gazania species and consideration of the name as a synonym of G. linearis is not supported. Similarly, all other recognised genera in the tribe Arctotideae can be discounted owing to incompatibility of the involucre, floret colouration and vegetative characters with the description of Arctotis staticifolia. Numerous Asteraceae species indigenous to the Cape region of South Africa produce capitula with white rayfloret limbs, but the majority are inconsistent with the growth habit, leaf morphology and arrangement, and other floret colouration characters described for Arctotis staticifolia. Such taxa include Cotula L. spp., Felicia reflexa 187 Typification of Arctotis species of Poiret ADANSONIA, sér. 3 • 2019 • 41 (14) fig. 2. — Neotype of Arctotis staticifolia Poir. (P00126589; left specimen). Reproduced under the terms of the Creative Commons Attribution License [CC BY 4.0] (https://creativecommons.org/licenses/by/4.0), © Muséum national d’Histoire naturelle, Paris. 188 ADANSONIA, sér. 3 • 2019 • 41 (14) McKenzie R. J. & Nepi C. DC., Gerbera L. spp., Lasiospermum bipinnatum (Thunb.) Druce, Mairia crenata (Thunb.) Nees, Osmitopsis asteriscoides (P.J.Bergius) Less., Othonna L. and Senecio L. spp. with white-radiate capitula, Poecilolepis Grau spp. and Ursinia pilifera (P.J.Bergius) Poir. A form of Felicia elongata O.Hoffm. ex Zahlbr. produces white rays marked purplish maroon at the base, but the species is a shrubby perennial with leaves not concentrated at the base of the plant, and the plant is coarsely hairy not glabrous. Several Dimorphotheca species indigenous to the Cape region have capitula with white rays, including D. pluvialis (L.) Moench and D. nudicaulis with rays marked purple at the base, and the abaxial surface of the ray limb may be white, purple or copper. The involucral bracts of Dimorphotheca taxa are consistent with Poiret’s description for A. staticifolia. Particularly in the taxon Dimorphotheca nudicaulis var. graminifolia, the leaves are linear-lanceolate and crowded in a basal tuft. This taxon is well-illustrated in a number of publications (e.g. Edwards 1818; Loddiges & Sons 1818; Hooker 1861; Marloth 1908). Dimorphotheca tragus is similar in vegetative characteristics to those described for Arctotis staticifolia but the ray florets are orange or yellow above and the disc floret corolla is blackish purple. The dimorphic cypselae of the disc and ray florets of Dimorphotheca nudicaulis var. graminifolia are depicted in the lower righthand corner of the Calendula graminifolia lectotype illustration (Fig. 1). Of coincidental interest, Candolle (1838) listed “D. staticefolia Vaill. act. par. 1720 (nomen opt.!)” in the synonymy of Dimorphotheca graminifolia, which was consistent with Linnaeus’s (1753) synonymy for Calendula graminifolia. There is no evidence to link Poiret’s concept of Arctotis staticifolia with the plant that Vaillant (1720) named “Dimorphotheca Statices folio”. However, Poiret’s (1810) diagnosis for Arctotis staticifolia is similar, but contains additional details, to Linnaeus’s (1753) diagnosis for Calendula graminifolia of “Calendula foliis linearibus subintegerrimis, caule subnudo”. Norlindh (1943) designated as the lectotype for Calendula graminifolia an illustration in Commelin (1701: t. 34) labelled with the polynomial Bellis Africana florum pediculis foliosis foliis angustis et integris. The same illustration and polynomial were cited by Vaillant (1720: 280) following the polynomial Dimorphotheca Statices folio, together with the polynomial Calendula Africana surrecta Roris marini foliis that was listed and illustrated by Plukenet (1700: 35, tab. 376, fig. 7). To our knowledge, the binomial “Dimorphotheca staticifolia” has not been validly published. We conclude that Poiret’s description of Arctotis staticifolia is not compatible with any member of the tribe Arctotideae and is consistent with a Dimorphotheca taxon, specifically Dimorphotheca nudicaulis var. graminifolia, based on the characters specified in the protologue. The search for original material of Arctotis staticifolia should continue so as to clarify Poiret’s intended application of the name. In the absence of original material, under ICN Arts 9.8 and 9.13 (Turland et al. 2018) we here designate a neotype for Arctotis staticifolia consistent with our interpretation of the protologue. The selected neotype (P barcode P00126589; Fig. 2) was formerly in the Herbier Poiret. The specimen fits well with Poiret’s description for Arctotis staticifolia and shows many of the salient characters described, namely leaves narrow, linear, glabrous, entire or distantly dentate, the leaves inserted only in the proximal portion of the stem, capitulum solitary on a long naked, shortly glandular-hairy peduncle, and involucre of acute, lanceolate bracts with ±hyaline margins. The specimen was originally identified as Calendula graminifolia L. and subsequently was annotated “arctotis tenuifolia . poir. ency. sup.”, likely in Poiret’s handwriting. The gathering is unmistakably a specimen of Dimorphotheca nudicaulis var. graminifolia, therefore Arctotis staticifolia is here placed in the synonymy of D. nudicaulis var. graminifolia. Under ICN Art. 9.19(a), if original material for Arctotis staticifolia is located at a future date, the choice of the neotype will be superseded by the original material. Arctotis tenuifoliA Poir. Linnaeus (1771) published the name Arctotis tenuifolia L. with the diagnosis “Arctotis flosculis radiantibus sterilibus ? foliis linearibus indivisis glabris.” The provenance of the species was stated to be “Habitat in Cap. b. spei [Caput bonae spei] littore maritimo.” No specimens or previously published descriptions or illustrations were cited in the protologue. The name is the basionym for the species currently known as Ursinia tenuifolia (L.) Poir. and was lectotypified to a specimen in the Linnaean Herbarium (Herb. Linn. No. 1036.24; LINN) by Prassler (1967). Arctotis tenuifolia L. was transferred to Ursinia by Poiret (1808), who repeated the above-mentioned diagnosis but with ’Arctotis’ substituted with ’Ursinia’. When publishing the combination, Poiret cited the basionym Arctotis tenuifolia L. (citing the treatments of that species by Linnaeus 1771: 288; Linnaeus 1781: 385; Lamarck 1783: 238; Willdenow 1803: 2361). Poiret (1810: 439) listed Arctotis tenuifolia with a very different diagnosis to that used by Linnaeus (1771), namely ’Arctotis caule fruticoso, glabro; foliis subfiliformibus, glabris, apice trifidis; pedunculis longissimis, unifloris’, and notably specified ’(N.)’. Poiret did not cite a previous publication in which the name Arctotis tenuifolia was used, as he did for other previously named Arctotis species, and specifically did not cite A. tenuifolia L. nor Ursinia tenuifolia (L.) Poir. In addition, Poiret cited only unspecified material in the Herbier Desfontaines and thus gave no indication of having examined Linnaean specimens. Given that Poiret (1808) had previously transferred Arctotis tenuifolia L. to Ursinia, and thus was clearly familiar with the Linnaean name, it is reasonable to interpret that Poiret (1810) intended to publish a new name for what he considered to be an Arctotis species based on material different to that of A. tenuifolia L. Poiret’s work long preceded the establishment of a code of rules for botanical nomenclature and, with the transfer of Arctotis tenuifolia L. to Ursinia, Poiret might have considered that the name “Arctotis tenuifolia” was available for use again. Regardless, it is concluded that Poiret (1810) validly published a new name, Arctotis tenuifolia Poir., which is a heterotypic homonym of A. tenuifolia L. and thus is nomenclaturally illegitimate under ICN Art. 53.1 (Turland et al. 2018). 189 Typification of Arctotis species of Poiret ADANSONIA, sér. 3 • 2019 • 41 (14) fig. 3. — Lectotype of Arctotis tenuifolia Poir. (FI053597). © Sezione di Botanica, Museo di Storia Naturale-Botanica, Università di Firenze, Firenze.