J. Jpn. Bot. 91: 7–12 (2016) An Emendation of Rhodocactus, a Genus Segregated from Pereskia (Cactaceae) a b,c, Issaku ASAI and Kazunori MIYATA * aNiihama, Ehime, JAPAN; bDepartment of Biological Science, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033 JAPAN; cPresent address: Izu Shaboten Park, 1317-13, Futo, Ito, Shizuoka, 413-0231 JAPAN *Corresponding author: [email protected] (Accepted on September 9, 2015) The genus Pereskia Mill. (Cactaceae), distributed in Latin America, is an archaic cactus characterized by the developed leaf blades. A molecular analysis of the genus (Edwards et al. 2005) found that Pereskia s.l. was grouped into three clades; ‘Andean’, ‘southern South American (SSA)’ and ‘Northern’. Accordingly, a new genus, Leuenbergeria, was established for the ‘Northern’ clade based on some morphological differences (Lodé 2013). The ‘Andean’ and the ‘SSA’ clades have usually not been treated as independent genera, even though they are sister groups. Moreover, the ‘Andean’ and the ‘SSA’ clades differ in presence/absence of foliage leaves on brachyblast. We here propose to apply Pereskia s. str. for the ‘Andean’ clade and Rhodocactus (A. Berger) F. M. Knuth for the ‘SSA’ clade. We here describe and provide new combinations for five species under Rhodocactus. Key words: Cactaceae, cactus, Leuenbergeria, Pereskia, Pereskioideae, Rhodocactus. Cactaceae are characterized by a succulent dry groves in Latin America, are thought to habit and spines with areoles, a kind of be the most primitive members of Cactaceae brachyblast. They comprise 1,816 species in 124 based on the unique foliage character and have genera (Hunt 2006). The family was classified traditionally been treated as a single genus, into three tribes: Pereskieae, Opuntieae and Pereskia (e.g. Hunt 2006). As such, Pereskia Cereeae (Britton and Rose 1919), or three comprises 17 species. subfamilies: Pereskioideae, Opuntioideae and A molecular analysis of Cactaceae, Cereoideae (Backeberg 1958, Ito 1988). Fearn especially focusing on Pereskia, revealed (1996) proposed that the genus Maihuenia that Pereskia s.l. is polyphyletic (Edwards placed in the Maihuenioideae. The Cactaceae et al. 2005) and divisible into three clades: are therefore classified as including four ‘Andean’, ‘southern South American (SSA)’ subfamilies: Pereskioideae, Maihuenioideae, and ‘Northern’. Although dendrograms showed Opuntioideae and Cactoideae (= Cereoideae) different topologies depending on the study (Anderson 2001, Hunt 2013). (Butterworth and Wallace 2005, Crozier 2005, The Pereskioideae, characterized by foliage Arakaki et al. 2011), the ‘Andean’, ‘SSA’ and leaves and distributed from forested areas to ‘Northern’ clades consistently formed distinct —7— 8 植物研究雑誌 第 91 巻 第 1 号 2016 年 2 月 groups in all of those studies, except one species, define Rhodocactus as comprising five species: P. lychnidiflora, that was assigned to different R. grandifolius, R. bahiensis (Gürke) I. Asai & positions in some cases. Accordingly, a new K. Miyata, R. nemorosus (Rojas) I. Asai & K. genus, Leuenbergeria, was established for the Miyata, R. sacharosa (Griseb.) Backeb., and R. ‘Northern’ clade based on some morphological stenanthus (F. Ritter) I. Asai & K. Miyata. differences (Lodé 2013). For the remaining clades, the ‘Andean’ and the ‘SSA’ clades were Key to the genera of Pereskioideae (Cactaceae) always shown to be polyphyletic or paraphyletic. 1. Stem without stomata; bark precocious ........... Arakaki et al. (2011) reported the genetic .................................................. Leuenbergeria affiliation between the ‘Andean’ and ‘SSA’ 1. Stem with stomata (except in R. nemorosus); clades to be comparable to the genetic affiliation bark formation delayed (except in P. among Cactoideae, Maihuenioideae and aculeata); Opuntioideae, indicating that the ‘Andean’ and 2. Brachyblast leaves present ... Rhodocactus ‘SSA’ clades diverged earlier than other genera 2. Brachyblast leaves absent (spines only in Cactaceae. present) ........................................ Pereskia The ‘Northern’ clade has such ancestral characteristics, as stems without stomata and Taxonomic treatment bark formed precociously, that are not shared Rhodocactus (A. Berger) F. M. Knuth, by other clades (Edwards and Donoghue 2006). Kaktus-ABC: 96 (1935). Emended here. The ‘SSA’ clade is distinctly arborescent, Pereskia subg. Rhodocactus A. Berger, produces pink flowers and has foliage leaves Kakteen [Backeb. & Knuth]: 43 (1929). on brachyblasts (brachyblast leaves), whereas Type: Rhodocactus grandifolius (Haw.) F. M. the ‘Andean’ clade are climbers or undershrubs, Knuth (= Pereskia grandifolia Haw.) produces smaller flowers and does not have Trees, 3–7 m tall. Bark formation delayed. brachyblast leaves but has spines on brachyblast Brachyblast leaves present. Flowers 3–5 cm in (Leuenberger 1986). diam. ‘SSA’ clade in molecular phylogenetics For the nomenclature, the ‘Andean’ clade (Edwards et al. 2005). contains type species of Pereskia, P. aculeata Distribution: Brazil, Bolivia, Paraguay, N Mill. Since the type species of Rhodocactus, R. Argentina, NW Uruguay. grandifolius (Haw.) F. M. Knuth is assignable to the ‘SSA’ clade, all the species in that clade Key to the species of Rhodocactus should belong to Rhodocactus. Rhodocactus, 1. Stem without stomata .......... 3. R. nemorosus however, cannot be applied to the ‘SSA’ clade in 1. Stem with stomata the original sense. 2. Flower petals erect or ascending ................. Rhodocactus was described by Berger (1926) ........................................... 5. R. stenanthus as a subgenus of Pereskia and later elevated to 2. Flower petals spreading generic level by Knuth (1935). Rhodocactus 3. Leaves mostly narrowly elliptic-obovate was defined on the basis of having parietal to elliptic-lanceolate; lateral veins 10–13 placentation and a more developed receptacle ................................... 1. R. grandifolius surrounding the ovary. Knuth (1935) listed 11 3. Leaves mostly obovate or elliptic- species in the genus, but all of the species of obovate; lateral veins 4–7 Rhodocactus, except for R. grandifolius are in 4. Tomentum of areoles pale gray; the ‘Andean’ or ‘Northern’ clades, not in the stomata present only around areoles ‘SSA’ clade (Edwards et al. 2005). The ‘Andean’ ................................ 4. R. sacharosa clade should be included in Pereskia. We here re- 4. Tomentum of areoles brown at least February 2016 The Journal of Japanese Botany Vol. 91 No. 1 9 in youth; stomata scattered on whole 2. Rhodocactus bahiensis (Gürke) I. Asai & stem ......................... 2. R. bahiensis K. Miyata, comb. nov. Basionym: Pereskia bahiensis Gürke in 1. Rhodocactus grandifolius (Haw.) F. M. Monatsschr. Kakteenk. 18: 86 (1908). Lectotype Knuth, Kaktus-ABC [Backeb. & Knuth]: 97 (Leuenberger 1986): BRAZIL. Bahia: Calderão, (1935). Neotype (Leuenberger 1986): Cult. hort. Oct 1906, E. H. G. Ule 7050 (HBG). Kew. “raised from seed collected by Bowie & Distribution: Bahia, Brazil. Cunningham in 1816 in the neighbourhood of Rio de Janeiro.” Drawing by T. Duncanson, June 3. Rhodocactus nemorosus (Rojas Acosta) I. 11, 1824 (K). Asai & K. Miyata, comb. nov. Pereskia grandifolia Haw., Revis. Pl. Succ. Basionym: Pereskia nemorosa Rojas Acosta, 85 (1821). Cat. Hist. Nat. Corrientes: 64 (1897). Neotype Cactus grandifolius (Haw.) Link, Enum. (Leuenberger 1986): ARGENTINA. Corrientes: Hort. Berol. Alt. 2: 25 (1822). Poso de los Libres, 10 Mar 1917, J. A. Shafer subsp. grandifolius. 127 (NY). Pereskia ochnocarpa Miquel, Bull. Sci. Pereskia amapola F. A. C. Weber, Dict. Phys. Nat. Neerl. 1: 48 (1838). Type: Brazil. Hort. [Bois]: 939 (1898). Type: PARAGUAY. Illustration of Cactus rosea Vellozo (nom. nud.), Asunción, Mar 1877, Balansa 2671 (P– Fl. flum.5 : 27. (1827). holotype). Pereskia rosea Hort. ex A. Dietrich, Allg. Pereskia argentina F. A. C. Weber, Dict. Gartenzeitung 19: 152 (1851). Type: Cult. hort. Hort. [Bois]: 939 (1898). Type: Not cited. Berol. “recieved from F. A. Haage, Erfurt, a Description based on young, sterile plant grown specimen of unknown origin.” Not preserved. from seed from Argentina. Pereskia tampicana F. A. C. Weber, Bull. Pereskia amapola var. argentina (F. A. C. Mus. Hist. Nat. (Paris) 4: 167 (1898). Type: Weber) F. A. C. Weber, Monatsschr. Kakteenk. Mexico. Tamaulipas: Nr. Tampico, at El Paso [Weingart] 14: 87 (1904). Type: Not preserved. de Doña Cecilia on the Río Pánuco, ca. 1895, Description based on living plant grown from Heese s.n. Not preserved. seed collected by Grosse in Paraguay, ca. 1899. Rhodocactus tampicanus (F. A. C. Weber) Distribution: S Brazil, Paraguay, NE Backeb., Cactaceae 1: 115 (1958). Argentina, NW Uruguay. Distribution: E Brazil. subsp. violaceus (Leuenb.) I. Asai & K. 4. Rhodocactus sacharosa (Griseb.) Miyata, comb. nov. Backeb., Kakteenlexikon 397 (1966). Type: Basionym: Pereskia grandifolia Haw. var. ARGENTINA. Salta: Orán, frequens in sepibus, violacea Leuenb. in Mem. New York Bot. Gard. 1873, Lorentz & Hieronymus 410 (GOET– 41: 116 (1986). Type: BRAZIL. Minas Gerais: holotype). Mun. de Santana do Riacho, area do futuro Pereskia sacharosa Griseb. in Abh. Königl. Parque Estadual da Serra do Cipó, 650 m, 23 Ges. Wiss. Göttingen 24: 141 (1879). Sep 1981, da Silva 89 (HRB–holotype). Pereskia moorei Britton & Rose, Cactaceae Pereskia grandifolia Haw. subsp. violacea (Britton & Rose) 1: 15 (1919). Type: BRAZIL. (Leuenb.) N. P. Taylor & Zappi, Cactaceae Matto Grosso: Corumbá, Tannay, 1891–92,