INTRODUCTION
⌅The genus Oxybasis Kar. & Kir. (Amaranthaceae s. l. sensu APGIII, 2009APGIII [The Angiosperm Phylogeny Group]2009. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III. Botanical Journal of the Linnean Society161: 105–121. 10.1111/j.1095-8339.2009.00996.x; APGIV, 2016APGIV [The Angiosperm Phylogeny Group]2016. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV. Botanical Journal of the Linnean Society: 1–20. 10.1111/boj.12385) was restored as a separate genus from Chenopodium L. based on morphological and molecular data by Fuentes-Bazan et al. (2012Fuentes-Bazan, S., Uotila, P. & Borsch, T.2012. A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). Willdenowia42: 5–24. 10.3372/wi.42.42101; see also Hernández-Ledesma et al., 2015Hernández-Ledesma, P., Berendsohn, W. G., Borsch, T., von Mering, S., Akhani, H., Arias, S., Castañeda-Noa, I., Eggli, U., Eriksson, R., Flores-Olvera, H., Fuentes-Bazán, S., Kadereit, G., Klak, C., Korotkova, N., Nyffeler, R., Ocampo, G., Ochoterena, H., Oxelman, B., Rabeler, R. K., Sanchez, A., Schlumpberger, B. O. & Uotila, P.2015. A taxonomic backbone for the global synthesis of species diversity in the angiosperm order Caryophyllales. Willdenowia45: 281–383. 10.3372/wi.45.45301), and it currently contains ca. 13 species, classified in five sections (Mosyakin, 2013Mosyakin, S. L.2013. New nomenclatural combinations in Blitum, Oxybasis, Chenopodiastrum, and Lipandra (Chenopodiaceae). Phytoneuron2013–56: 1–8., 2018Mosyakin, S. L.2018. New combinations for three taxa of the Oxybasis glauca aggregate (Chenopodiaceae) from Australasia, East Asia, and South America. Phytotaxa250(3): 259–273. 10.11646/phytotaxa.350.3.5). Oxybasis is nowadays widely accepted by many authors (e.g. Mosyakin, 2013Mosyakin, S. L.2013. New nomenclatural combinations in Blitum, Oxybasis, Chenopodiastrum, and Lipandra (Chenopodiaceae). Phytoneuron2013–56: 1–8.; Sukhorukov et al., 2013Sukhorukov, A. P., Uotila, P., Zhang, M., Zhang, H.-X., Speranskaya, A. S. & Krinitsyna, A. A.2013. New combinations in Asiatic Oxybasis (Amaranthaceae s. l.): evidence from morphological, carpological and molecular data. Phytotaxa144(1): 1–12. 10.11646/phytotaxa.144.1.1, 2015Sukhorukov, A. P., Nilova, M. V., Erst, A. S. & Krinitsyna, A. A.2015. Exact delimitation of the morphologically similar but phylogenetically distant genera Blitum and Oxybasis (Chenopodiaceae–Amaranthaceae): a case study of several enigmatic taxa. In: Caryophyllales 2015 – Conference Programme and Abstracts. (Berlin, 14–19 September 2015). Botanic Garden and Botanical Museum Berlin-Dahlem & Freie Universität Berlin, Berlin: 45.; Verloove, 2013Verloove, F.2013. A new combination in Oxybasis (Amaranthaceae). New Journal of Botany3(1): 59–60. 10.1179/2042349712Y.0000000015; Iamonico, 2014Iamonico, D.2014. Taxonomical morphological ecological and chorological notes on Oxybasis chenopodioides and O. rubra (Chenopodiaceae) in Italy. Hacquetia13(2): 297–302. 10.2478/hacq-2014-0005; Sukhorukov, 2014Sukhorukov, A. P.2014. Карпология семейства Chenopodiaceae в связи с проблемами филогении, систематики и диагностики его представителей [The carpology of the family Chenopodiaceae with reference to the phylogeny, systematics and diagnostics of its representatives]. Grif & K, Tula [In Russian].; Mereďa, 2016Mereďa, S. P.jun. 2016. Oxybasis Kar. & Kir. In: Goliašová, K. & Michalková, E. (Eds.), Flóra Slovenska 6(4): 231–253, 723.).
Oxybasis rubra (L.) S. Fuentes, Uotila & Borsch is naturally distributed in the northern temperate hemisphere (POWO, 2024POWO [Plants of the World Online]2024. Oxybasis rubra (L.)Fuentes, Uotila & Borsch. Retrieved onAugust 12, 2024, fromhttps://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:77121013-1). It is a morphological variable species that has often misidentified as O. chenopodioides (L.) S. Fuentes, Uotila & Borsch (see e.g. Iamonico, 2014Iamonico, D.2014. Taxonomical morphological ecological and chorological notes on Oxybasis chenopodioides and O. rubra (Chenopodiaceae) in Italy. Hacquetia13(2): 297–302. 10.2478/hacq-2014-0005).
Uotila (2011Uotila, P.2011. Oxybasis rubra (L.) S. Fuentes, Uotila & Borsch. In: Euro+Med PlantBase - he information resource for Euro-Mediterranean plant diversity. Botanic Garden and Botanical Museum Berlin-Dahlem, Berlin. RetrievedAugust 12, 2024, fromhttp://euromed.luomus.fi/euromed_map.php?taxon=549009&size=medium) recorded Oxybasis rubra in most of the European countries (including Sardinia) on the basis of the Checklist of the Italian Vascular Flora by Conti et al. (2005Conti, F., Abbate, G., Alessandrini, A. & Blasi, C. (Eds.) 2005. An Annotated Checklist of the Italian Vascular Flora. Palombi Editori, Roma.). Also Pignatti (1982Pignatti, S.1982. Flora d’Italia 1 . Edagricole, Bologna.), in the first edition of Flora d’Italia, and Mossa et al. (2004Mossa, L., Guarino, R., Fogu, M. C.2004. La componente terofitica della flora della Sardegna. Forme di crescita, ecologia, corologia e sinsistematica. Rendiconti del Seminario della Facoltà di Scienze dell’Università di Cagliari73(2): 1–209.) reported this species as occurring in the island. Arrigoni (2006Arrigoni, P. V.2006. Flora dell’isola di Sardegna 1. Carlo Delfino Editore, Sassari.) in his Flora dell’Isola di Sardegna listed it as doubtful species for the island. Iamonico (2017Iamonico, D.2017. Oxybasis Kar. & Kir. In: Pignatti, S. (Ed.), Flora d’Italia 2. Edagricole, Bologna: 247–249.) reported the species as erroneusly recorded in Sardinia. Both the subsequent updating to the Italian flora (Conti et al., 2007Conti, F., Alessandrini, A., Bacchetta, G., Banfi, E., Barberis, G., Bartolucci, F., Bernardo, L., Bonacquisti, S., Bouvet, D., Bovio, M., Brusa, G., Del Guacchio, E., Foggi, B., Frattini, S., Galasso, G., Gallo, L., Vangale, C., Gottschlich, G., Grünanger, P., Gubellini, L., Iiriti, G., Lucarini, D., Marchetti, D., Moraldo, B., Peruzzi, L., Poldini, L., Prosser, F., Raffaelli, M., Santangelo, A., Scassellati, E., Scortegagna, S., Selvi, F., Soldano, A., Tinti, D., Ubaldi, D., Uzunov, D. & Vidali, M.2007. Integrazioni alla checklist della flora vascolare italiana. Natura Vicentina10: 5‒74.), the detailed study on the aggregate Oxybasis rubra/chenopodioides by Iamonico (2014Iamonico, D.2014. Taxonomical morphological ecological and chorological notes on Oxybasis chenopodioides and O. rubra (Chenopodiaceae) in Italy. Hacquetia13(2): 297–302. 10.2478/hacq-2014-0005), and the recent new Italian Checklist (Bartolucci et al., 2018Bartolucci, F., Peruzzi, L., Galasso, G., Albano, A., Alessandrini, A., Arenghi, N. M. G., Astuti, G., Bacchetta, G., Balzelli, S., Banfi, E., Barberis, G., Bernardo, L., Bouvet, D., Bovio, M., Cecchi, L., Di Pietro, R., Domina, G., Fascetti, S., Fenu, G., Festi, F., Foggi, B., Gallo, L., Gottschlich, G., Gubellini, L., Iamonico, D., Iberite, M., Jiménez-Mejías, P., Lattanzi, E., Marchetti, D., Martinetto, E., Masin, R. R., Medagli, P., Passalacqua, N. G., Peccenini, S., Pennesi, R., Pierini, B., Poldini, L., Prosser, F., Raimondo, F. M., Roma-Marzio, F., Rosati, L., Santangelo, A., Scoppola, A., Scortegagna, S., Selvaggi, A., Selvi, F., Soldano, A., Stinca, A., Wagensommer, R. P. & Wilhalm, T.2018. An updated checklist of the vascular flora native to Italy, Plant Biosystems152(2): 179–303, 10.1080/11263504.2017.1419996; see also Portal of Flora of Italy, 2024Portal of Flora of Italy2024. Oxybasis rubra (L.)S. Fuentes, Uotila & Borsch. Retrieved onAugust 12, 2024, fromhttps://dryades.units.it/FVG/index.php?procedure=taxon_page&id=459&num=1923) considered O. rubra as not included in the regional flora being recorded in the past as a mistake. POWO (2024POWO [Plants of the World Online]2024. Oxybasis rubra (L.)Fuentes, Uotila & Borsch. Retrieved onAugust 12, 2024, fromhttps://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:77121013-1) does not record O. rubra in Sardinia.
As part of an ongoing study on Chenopodium s. l. (e.g. Iamonico, 2010Iamonico, D.2010. Confirmation of the occurrence of Chenopodium strictum subsp. strictum (Amaranthaceae s. l.) in Italy. Phyton (Horn Austria)49(2): 235–240., 2011Iamonico, D.2011. Dysphania anthelmintica (Amaranthaceae), new to the non–native flora of Italy, and taxonomic considerations on the related species. Hacquetia10(1): 41–48. 10.2478/v10028-011-0002-x, 2013Iamonico, D.2013. Chenopodium sensu lato (Chenopodiaceae, Chenopodioideae) nella flora vascolare italiana: chiave analitica dei generi. Informatore Botanico Italiano45(1): 83–88., 2019Iamonico, D.2019. Remarks on the nomenclature of Betoideae (Chenopodiaceae/Amaranthaceae sensu APGIV). Phytotaxa400(3): 145–164. 10.11646/phytotaxa.400.3; Iamonico et al., 2015Iamonico, D., Sukhorukov, A. P. & Reveal, J. L.2015. (2360) Proposal to reject the name Chenopodium caudatum (Amaranthaceae / Chenopodiaceae). Taxon64(3): 638–639. 10.12705/643.18, 2022Iamonico, D., SciutoK., SfrisoA., ArgentiC., MarionA. F.2022. Blitum venetum (Chenopodiaceae), a new species from the north-eastern Dolomites (Italian Eastern Alps). Acta Botanica Croatica81(2): 121–128. 10.37427/botcro-2022-009; Mosyakin & Iamonico, 2017Mosyakin, S. L. & Iamonico, D.2017. Nomenclatural changes in Chenopodium (incl. Rhagodia) (Chenopodiaceae) with considerations on relationships of some Australian taxa and their possible Eurasian relatives. Nuytsia28: 255–271. 10.58828/nuy00843; Iamonico & Mosyakin, 2018Iamonico, D. & Mosyakin, S. L.2018. Studies on Chenopodium album s. l. (Chenopodiaceae / Amaranthaceae s. l.): Chenopodium pedunculare. Annali di Botanica (Roma)8: 67–74. 10.4462/annbotrm-14240, 2020Iamonico, D. & Mosyakin, S. L.2020. Lectotypification of names associated with Chenopodium hircinum (Chenopodiaceae / Amaranthaceae sensu APG): C. bonariense Tenore and two varieties described by Aellen. Phytotaxa443(1): 116–120. 10.11646/phytotaxa.443.1.11; Iamonico & El Mokni, 2019Iamonico, D. & El Mokni, R.2019. On Atriplex canescens (Chenopodiaceae s. str./ Amaranthaceae s. l.) in Tunisia: nomenclatural and morphological notes on its infraspecific variability. Hacquetia18(1): 119–127. 10.2478/hacq-2018-0008), field surveys carried out during the last years in Sardinia allowed us to find some populations referable to Oxybasis rubra, a discover which represents a confirmation of the species in the Island. Based on the literature review, the names Chenopodium blitoides Lej., which is currently considered so by almost all the literature consulted as synonym of Oxybasis rubra, and C. humile Hook., which is currently accepted as a good taxon at variety rank of C. rubrum or O. rubra [C. rubrum var. humile (Hook.) S. Watson, or O. rubra var. humilis (Hook.) S. Mosyakin; see e.g. Clemants & Mosyakin, 2003Clemants, S. E. & Mosyakin, S. L.2003. Chenopodium L. In: Flora of North America Editorial Committee (Eds.), Flora of North America North of Mexico 4. Oxford University Press, New York & Oxford: 175–299.; Mosyakin, 2013Mosyakin, S. L.2013. New nomenclatural combinations in Blitum, Oxybasis, Chenopodiastrum, and Lipandra (Chenopodiaceae). Phytoneuron2013–56: 1–8.] need to be clarified, and they are also investigated in the present paper.
MATERIALS AND METHODS
⌅The present work is based on a review of the relevant literature (e.g. Pignatti, 1982Pignatti, S.1982. Flora d’Italia 1 . Edagricole, Bologna.; Arrigoni, 2006Arrigoni, P. V.2006. Flora dell’isola di Sardegna 1. Carlo Delfino Editore, Sassari.; Iamonico, 2014Iamonico, D.2014. Taxonomical morphological ecological and chorological notes on Oxybasis chenopodioides and O. rubra (Chenopodiaceae) in Italy. Hacquetia13(2): 297–302. 10.2478/hacq-2014-0005; Portal of Flora of Italy, 2024Portal of Flora of Italy2024. Oxybasis rubra (L.)S. Fuentes, Uotila & Borsch. Retrieved onAugust 12, 2024, fromhttps://dryades.units.it/FVG/index.php?procedure=taxon_page&id=459&num=1923; POWO 2024POWO [Plants of the World Online]2024. Oxybasis rubra (L.)Fuentes, Uotila & Borsch. Retrieved onAugust 12, 2024, fromhttps://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:77121013-1), floristic surveys, and checking and examination of material preserved at BR, CAG, FI, K, LINN, and RO (acronyms according to Thiers, 2024Thiers, B.2024 [continuously updated]. Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. Retrieved on August 12, 2024, from http://sweetgum.nybg.org/ih/. [continuously updated]), and in the personal Herbarium Giuliano Mereu (not listed in Index Herbariorum). The articles cited throughout the text follow the Shenzen Code (Turland et al., 2018Turland, N. J., Wiersema, J. H., Barrie, F. R., Greuter, W., Hawksworth, D. L., Herendeen, P. S., Knapp, S., Kusber, W.-H., Li, D.-Z., Marhold, K., May, T. W., McNeill, J., Monro, A. M., Prado, J., Price, M. J. & Smith, G. F. (Eds.) 2018. International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code) adopted by the Nineteenth International Botanical Congress Shenzhen, China (Regnum Vegetabile, 159). Koeltz Botanical Books, Glashütten. 10.12705/Code.2018, hereafter reported as “ICN”). The description of the species is based on plants collected in Sardinia.
RESULTS
⌅Chenopodium blitoides
⌅Chenopodium blitoides was described by Lejeune (1811Lejeune, A. L. S.1811. Flore des environs de Spa, ou, distribution selon le système de Linnaeus, des plantes qui crossent spontanément dans le département de l’Ourte et dans les départements circonvoisins, pour servir de suite à la Flore du Nord de la France de Mr. Roucel. Duvivier, Liége.: 126) who provided a diagnosis and the provenance (“Se trouve dans le fossés des fortification de la ville de Maastricht”).
According to Stafleu & Cowan (1979Stafleu, F. A. & Cowan, R. S.1979. Taxonomic Literature. Second edition II: H-Le. The Hague, Utrecht.: 830), Lejeune’s collection is preserved at BR. Lejeune’s herbarium was in fact acquired, after his death, in 1871, by the Jardin botanique de Bruxelles (now Botanic Garden Meise; herbarium BR) (see Verloove, 2017Verloove, F.2017. Typification and identity of species of Veronica subgenus Pseudolysimachium (Plantaginaceae) described from Belgium by A. L. S. Lejeune. New Phytotaxa329(3): 296–298. 10.11646/phytotaxa.329.3.14). Most of Lejeune’s specimens, however, only bear a name in Lejeune’s handwriting, without indication of date and/or locality. Hence, there seems to be no extant material that doubtlessly was at Lejeune’s disposal when he described taxa between 1811 and 1824 (Verloove, 2017Verloove, F.2017. Typification and identity of species of Veronica subgenus Pseudolysimachium (Plantaginaceae) described from Belgium by A. L. S. Lejeune. New Phytotaxa329(3): 296–298. 10.11646/phytotaxa.329.3.14). Only one specimen of Chenopodium blitoides was found at BR (barcode BR1-190-092), and it bears two plants and the following two original labels: “Blitum rubrum | DC. prodr. t. 13 p. 2 p. 87 | HERB. HORT. BRUXELL. | Coll. LEJEUNE”, and “Chenopodium | Blitum rubrum var. blitoides | fl. fr. | DC. prodr. t. 13 p. 2 p. 87 | HERB. HORT. BRUXELL. | Coll. LEJEUNE”. Since both the dates and localities of collection are lacking, this specimen cannot be considered as part of the original material with certainty and is not eligible as lectotype (Arts. 9.3 and 9.4 of ICN). A neotypification is therefore necessary (Art. 9.8 of ICN). BR1-190-092 is here designated as the neotype of the name Chenopodium blitoides.
On the basis of the current concept in Oxybasis (e.g. Akeroyd, 1993Akeroyd, J. R.1993. Chenopodium L. In: Tutin, T. G., Heywood, W. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M., Webb, D. A. (Eds), Flora Europaea 1. Cambridge University Press, Cambridge: 111–114.; Clemants & Mosyakin, 2003Clemants, S. E. & Mosyakin, S. L.2003. Chenopodium L. In: Flora of North America Editorial Committee (Eds.), Flora of North America North of Mexico 4. Oxford University Press, New York & Oxford: 175–299.; Iamonico, 2014Iamonico, D.2014. Taxonomical morphological ecological and chorological notes on Oxybasis chenopodioides and O. rubra (Chenopodiaceae) in Italy. Hacquetia13(2): 297–302. 10.2478/hacq-2014-0005, 2017Iamonico, D.2017. Oxybasis Kar. & Kir. In: Pignatti, S. (Ed.), Flora d’Italia 2. Edagricole, Bologna: 247–249.), BR1-190-092 is identifiable as O. rubra var. rubra and Chenopodium blitoides is a heterotypic synonym.
Chenopodium humile
⌅Hooker (1838Hooker, W. J.1838. Flora boreali-americana, or, the botany of the northern parts of British America 2. Henry G. Bohn, London.10.5962/bhl.title.691: 127) proposed Chenopodium humile to describe small forms of Chenopodium from Saskatchewan (“Saskatchawan” is reported in the protologue), an administrative province of South Canada.
According to Stafleu & Cowan (1979Stafleu, F. A. & Cowan, R. S.1979. Taxonomic Literature. Second edition II: H-Le. The Hague, Utrecht.: 283), Hooker’s collection is preserved at K, where we traced one specimen (barcode K000898463, on the right of the sheet), which is pinned with further two collections (barcodes K000898462 and K000898464; image of the sheet at https://www.kew.org/herbcatimg/544064.jpg). K000898463 is linked to the label “Chenop. humile | Saskatchewan | Drummond” and matches Hooker’s diagnosis. Hooker (1838Hooker, W. J.1838. Flora boreali-americana, or, the botany of the northern parts of British America 2. Henry G. Bohn, London.10.5962/bhl.title.691) did not indicate any collector in the protologue. However, note that “Drummond” was reported just above in Flora boreali-americana (same and previous pages of the protologue of C. humile) as collector of other Chenopodium species, i.e. C. calceliforme Hook. (Saskatchewan was not reported among the localities of this species), C. rubrum L. (“Hab. About the Saskatchewan. Drummond”), C. urbicum L. (“Hab. ... Saskatchewan ... Drummond”), and C. glaucum L. (Saskatchewan was not reported among the localities of this species). So, we can presume that Drummond could be also the collector of C. humile. Despite this, since the date of collection is lacking in K000898463, we cannot be sure that the plant was an ante-1838 addition to the collection, and we prefer to consider this specimen as not part of the original material used by Hooker to describe C. humile. All things considered, no specimen useful for a lectotypification purpose was traced, a neotype should be designated (Art. 9.8 of ICN). K000898463 is here designated as the neotype of the name Chenopodium humile.
The taxon humile has been treated at different ranks during the time (from species to variety and form), whereas in other cases it was not recognized at all. According to Clemants & Mosyakin (2003Clemants, S. E. & Mosyakin, S. L.2003. Chenopodium L. In: Flora of North America Editorial Committee (Eds.), Flora of North America North of Mexico 4. Oxford University Press, New York & Oxford: 175–299.), Hooker’s species is native in NW-America and introduced to East, while Brouillet et al. (2010Brouillet, L., Coursol, F., Meades, S. J., Favreau, M., Anions, M., Bélisle, P. & Desmet, P.2010. Oxybasis rubra var. humilis (Hooker) Mosyakin. In: VASCAN - the Database of Vascular Plants of Canada. RetrievedFebruary 26, 2020, fromhttp://data.canadensys.net/vascan/taxon/27673) reported it in Canada as native in Ontario, Nova Scotia, New Brunswick, British Columbia, Saskatchewan, Alberta, and Yukon. Waiting for further investigations on this taxon, we here accept it at variety rank according to Clemants & Mosyakin (2003Clemants, S. E. & Mosyakin, S. L.2003. Chenopodium L. In: Flora of North America Editorial Committee (Eds.), Flora of North America North of Mexico 4. Oxford University Press, New York & Oxford: 175–299.).
Occurrence in Sardinia of Oxybasis rubra var. rubra
⌅Twenty populations of Oxybasis rubra var. rubra were found in three Administrative Units of Sardinia [Metropolitan City of Cagliari (localities: Colostrai and Torre Salinas, and S. Giovanni), Province of Nuoro (Cala Gonone-Dorgali, Gairo, Scogliera di Punta su Mastixi-Bari Sardo, Su Sirboni), and Province of South Sardinia (Nuraghe Murtas-Muravera)] along the western coast (Fig. 1). In these sites, the plants are grouped in small populations (less than 30 individuals per population). They thrive in diverse habitats, encompassing salt marshes, sea shores (Fig. 2A), pond banks, human-made environments such as roadsides or anthroposols formed from the accumulation of various materials, and even basaltic rocky areas (Fig. 2B), as observed at one site. As highlighted by Iamonico (2014Iamonico, D.2014. Taxonomical morphological ecological and chorological notes on Oxybasis chenopodioides and O. rubra (Chenopodiaceae) in Italy. Hacquetia13(2): 297–302. 10.2478/hacq-2014-0005: 290), Oxybasis rubra has wider ecological demands than O. chenopodioides. Oxybasis rubra occurs in both natural and synanthropic habitat, which are characterized respectively by soils humid and not, whereas O. chenopodioides colonizes habitats with a seasonal cycle of submersion (mainly during the winter, with rain) and emersion (during the summer and autumn) (see Iamonico, 2014Iamonico, D.2014. Taxonomical morphological ecological and chorological notes on Oxybasis chenopodioides and O. rubra (Chenopodiaceae) in Italy. Hacquetia13(2): 297–302. 10.2478/hacq-2014-0005: 287)].
No specimen identifiable as Oxybasis rubra were traced at CAG, which is the main Sardinian herbarium.
TAXONOMIC TREATMENT
⌅Oxybasis rubra (L.) S. Fuentes, Uotila & Borsch, Willdenowia 42: 15 (2012Fuentes-Bazan, S., Uotila, P. & Borsch, T.2012. A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). Willdenowia42: 5–24. 10.3372/wi.42.42101) var. rubra ≡ Chenopodium rubrum L., Sp. Pl. 1: 218 (1753) ≡ Blitum rubrum (L.) Rchb., Fl. Germ. Excurs. 2(1): 582 (1832).
Type (designated by Uotila, 1993Uotila, P.1993. Taxonomic and nomenclatural notes on Chenopodium in the Flora iranica area. Annales Botanici Fennici30: 189–194.): Herb. Linnaeus 313.5 (lectotype LINN!, image available at http://linnean-online.org/3079/).
= Chenopodium blitoides Lej., Fl. Spa 1: 126 (1811).
Neotype (designated here): Belgium, Liège, Spa, s.d., A.L.S. Lejeune s.n. (BR1-190-092!). Fig. 3.
Description: annual herbaceous (therophyte), with herbaceous smell, 20−100 cm tall. Stem glabrous (slightly farinose along the inflorescence), more or less branched (branches erect, irregularly ribbed), green to red. Leaves green to dark-green, slightly shiny, petiolate (petiole 5−45 mm long), with blades green to red (especially at the apex), slightly fleshy, ovate-rhomboidal (2.5−6.0 × 50−80 mm, reduced in size towards the distal part of the plant), margin irregularly dentate (2−3 acute teeth per side), base cuneate. Flowers grouped in not fleshy glomerules; glomerules arranged in spike-like structures each subtended by one bract-like leaf; tepals five, connate only at the base, keeled at maturity (keeled only in the distal part when young), rounded at the apex, green (red in the distal part at maturity), sparsely farinose. Fruits each with one seed, discoidal (diameter 1.2−1.5 mm), slightly wrinkled or punctulate, blackish to brown.
Flowering time: February−April.
Specimina Visa Selecta: Italia, Puglia: Taranto, Lungomare Vittorio Emanuele III, muri e bordi di aree pedonali, 7 m, 14.IV.2013, leg. T. Dura, det. D. Iamonico & T. Dura (FI). Sardegna: Cagliari, Muravera, stagno di Colostrai, sponda orientale dello stagno con prevalente prateria di Salicornia fruticosa (L.) L., 39.353460° N, 9.593219° E (WGS84), 1 m a.s.l., 14.III.2015, leg. G. Mereu, det. G. Mereu & D. Iamonico (RO, Herb. Mereu); Cagliari, Muravera, spiaggia di S. Giovanni, parte alta della spiaggia e area sabbiosa limitrofa, 39.396119° N, 9.611084° E (WGS84), 2 m a.s.l., 14.III.2015, leg. G. Mereu, det. G. Mereu & D. Iamonico (RO); Ogliastra, Bari Sardo, loc. Su Mastixi, scogliera basaltica, 39.853782° N, 9.695387° E (WGS84), 3 m a.s.l., 02.V.2015, leg. G. Mereu, det. G. Mereu & D. Iamonico (RO); Nuoro, Dorgali, Porto di Cala Gonone, terrapieno del molo settentrionale, 40.283899°N, 9.639155°E (WGS84), 3 m a.s.l., 23.V.2015, leg. G. Mereu, det. G. Mereu & D. Iamonico (Herb. Mereu); Cagliari, Muravera, Nuraghe Murtas, bordo di strada sterrata presso stagno salmastro, 39.406794° N, 9.603177° E (WGS84), 3 m a.s.l., 10.I.2016, leg. G. Mereu, det. G. Mereu & D. Iamonico (Herb. Mereu); Nuoro, Ogliastra, Gairo, Spiaggia di Coccorrocci, bordo di macchia mediterranea retrodunale, 39.728981° N, 9.674510° E (WGS84), 5 m a.s.l., 15.IV.2018, leg. G. Mereu, det. G. Mereu & D. Iamonico (Herb. Mereu); Cagliari, Muravera, Spiaggia di Colostrai, bordo di strada sterrata presso depressione retrodunale salsa, 39.361214° N, 9.597575° E (WGS84), 3 m a.s.l., 28.IV.2018, leg. G. Mereu, det. G. Mereu & D. Iamonico (Herb. Mereu).
Oxybasis rubra (L.) S. Fuentes, Uotila & Borsch, Willdenowia 42: 15 (2012) var. humilis (Hook.) S. Mosyakin, Phytoneuron 56: 1–8 (2013) ≡ Chenopodium humile Hook., Fl. Bor.-Amer. 2: 127 (1838).
Neotype (designated here): Canada, Saskatchewan, s.d., T. Drummond s.n. K000898463! [plant on the right of the sheet], image available at https://www.kew.org/herbcatimg/544064.jpg).