Acta Botanica 1-2015 - za web.indd ACTA BOT. CROAT. 74 (1), 2015 143 Acta Bot. Croat. 74 (1), 143–150, 2015 CODEN: ABCRA 25 ISSN 0365-0588 eISSN 1847-8476 Short communication Manihot grahamii Hook. (Euphorbiaceae), a new alien species for the Eurasian area with nomenclatural, taxonomical, morphological and ecological notes MAURO IBERITE1*, DUILIO IAMONICO2 1 Department of Environmental Biology, University of Rome Sapienza, piazzale Aldo Moro 5, 00185 Rome, Italy 2 Laboratory of Phytogeography and Applied Geobotany, Department PDTA, Section Environment and Landscape, University of Rome Sapienza, via Flaminia 72, 00196 Rome, Italy Abstract – Manihot is a native genus of the Northern and Southern America with diversi- ty centres in Brazil, Mexico and Guatemala. Some taxa have colonized other continents (except Europe) where they are considered aliens. During recent fl oristic surveys we found the genus in the Agro Pontino area (Lazio region, Central Italy, Southern Europe). This is the second record in Europe for the genus and the fi rst of M. grahamii for the Eurasian area. At present this taxon is to be considered as naturalized alien species in Agro Pontino (and thus in Italy and Europe). To better clarify the taxonomic and nomenclatural data, the names Janipha loefl ingii var. (ß) multifi da (≡ M. grahamii) and Jatropha carthaginensis (≡ M. carthaginensis) were lectotypifi ed respectively on a specimen from K and an iconogra- phy by Jacquin. Key words: Asia, Europe, Italy, lectotypifi cation, Manihot Mill., Manihot carthaginensis (Jacq.) Müll. Arg., status of naturalization, synonymy Introduction Manihot Mill. (Euphorbiaceae, Crotonoideae) is a genus of about 75–100 species dis- tributed in America, from Arizona to Argentina and West Indies (ROGERS and APPAN 1973, CHACÓN et al. 2008, APGIII 2009). Its distribution area is disjunct: none of the North and Central American species occur in South America. Centres of diversity are two: Brazil, with about 80 species (66 endemic, according to CORDEIRO and SECCO 2010) and from Mex- ico to Guatemala with 18 species. Molecular studies confi rm this disjunction, showing a * Corresponding author, e-mail: mauro.iberite@uniroma1.it Copyright® 2015 by Acta Botanica Croatica, the Faculty of Science, University of Zagreb. All rights reserved. IBERITE M., IAMONICO D. 144 ACTA BOT. CROAT. 74 (1), 2015 dichotomy between the Mesoamerican and South American Manihot species (CHACÓN et al. 2008). Out of its native range, Manihot was recorded as alien genus, in North America (11 species; USDA 2012), Asia (4 species; RADCLIFFE-SMITH 1986; LI and GILBERT 2008; IBIN 2012), Africa (7 species; SANBI 2005–2010, BIOTA AFRICA 2012) and Australia (6 species; APNI 2012). Recent fl oristic surveys in the Agro Pontino area (Lazio region, central Italy, Southern Europe) allowed to fi nd a population referring to the genus Manihot and in par- ticular to M. grahamii Hook. This gathering represents the second record of the genus Manihot in Europe and the fi rst of M. grahamii in the Eurasian area. Due to the diffi culties in the identifi cation, it was necessary to investigate the nomenclatural aspects of this spe- cies and M. carthaginensis (Jacq.) Müll. Arg., being M. grahamii related to this name in the past. Taxonomical notes, morphological data in comparison with the related species M. in- fl ata Mueller and M. janiphoides Mueller and ecological observations were provided. Material and methods The present study was the result of personal fi eld investigations, examination of the specimens kept in the Herbaria RO, LINN, K, P, W (abbreviations according to THIERS 2011) and the analysis of literature (protologues included). The nomenclature follows ROG- ERS and APPAN (1973). The status of naturalization was evaluated according to PYŠEK et al. (2004), RICHARDSON and PYŠEK (2006), RICCIARDI and COHEN (2007). The descriptions are based on personal observations of diagnostic characters (leaves shape and infl orescence structure). Results and discussion According to ROGERS and APPAN (1973) M. grahamii is included in the Sect. Hetero- phyllae Pax emend. Rogers & Appan (18 sections are recognized in the genus Manihot) a South American group characterized by low to medium tall plants (shrubs or small tree), with not tomentose abaxial surface of the leaves blade and leaves lobes entire to pandurate, infl orescence in panicle, bracts and bracteoles foliaceous and entire. Plants from Italy (Agro Pontino area, Central Italy) clearly refer to this section. Among the taxa included into the Sect. Heterophyllae, M. grahamii seems to be related to M. infl ata and M. janiphoides. All these species are included in the group of taxa with bracts and bracteoles setaceous less than 25 mm wide and infl orescence in a panicle with one main axis and spaced fl owers. The analyses of the morphological features and qualitative characters shows that M. grahamii is characterized by leaves blade glabrous abaxially, 7-lobed or more with lobes at the base more than 25 mm wide, while M. janiphoides has leaves lobe densely pubescent and M. infl ata has leaves 3–5 lobed each lobe at the base less that 25 mm wide. Typifi cation of Manihot grahamii Manihot grahamii was described from Paraná, South America (HOOKER 1842). The pro- tologue consists of a diagnosis with habitat, provenance and collector (»HAB. Woods of the Parana. Tweedie«) and one synonym (»Janipha loefl ingii...(excl. Syn.)―β multifi da«) cited from GRAHAM (1840: 172–173). HOOKER (l. c.) dedicated the taxon to R. Graham, observing that M. grahamii partially refers to Janipha loefl ingii Humb., Bompl. et Kunth var. multifi - MANIHOT GRAHAMII HOOK. IN EURASIAN AREA ACTA BOT. CROAT. 74 (1), 2015 145 da Graham. Anyhow a new combination of this name cannot be proposed since a previous homonym was published by CRANTZ (1766: 67), so Hooker (l. c.) proposed a nomen novum avoiding an illegitimate combination. ROGERS and APPAN (1973: 88) stated the existence of three specimens at K (»Type syntypes, K-3«). We found seven sheets at K (THE HERBARIUM CATALOGUE, ROYAL BOTANICAL GARDEN, KEW 2015), two of which (Codes K000600382 and K000600383) cannot be considered for the typifi cation since they were collected by E. Hassler, not by J. Tweedie. The other fi ve exsiccata include Tweedie’s handwriting and signature. One of these (code K000600377) came from »Portalegre« (now the city of Porto Alegre) a locality placed along the South-Eastern coast of South America, in Rio Grande do Sul state (Brazil). Since this locality was not cited in the protologue by HOOKER (l. c.) the specimen cannot be eligible as the lectotype. The remains exsiccata (Codes K000600378- 381) were collected by J. Tweedie from »parana« (it probably refers to the current Paraná state, Brazil). However, only one (Code K000600379) includes the date of collection (»1837«) and it can be considered certainly original material, while the sheets with Codes K000600378, -380, -381 lack of this information. So, they might refer to a later collection (post 1842, the year of Hooker’s publication) and could not be original material. Since the exsiccatum K000600379 is the only extant and certain original material, matching with the diagnosis, it is here designated as the lectotype of M. grahamii. Manihot grahamii Hook., Icon. Pl., 6: t. 530. 1842. Lectotype (here designated): Argentina, »a beautiful decidious tree of the parana«, 1837, J. Tweedie s. n. (K000600379!). Image of the lectotype available at http://apps.kew. org/herbcat/getImage.do?imageBarcode=K000600379 ≡ Janipha loefl ingii Kunth var. (ß) multifi da Graham, Edinburgh New Philos. J. 29: 172. 1840 non CRANTZ (1766: 67). ≡ Manihot tweediana Müll. Arg., Fl. Bras. (Martius) 11(2): 450. 1873–1874, nom. illeg., nom. superfl . (art. 52.1 of the ICN). Description: Arborescent shrubs to low trees to 3.5 m tall, forming an umbrella-like dense canopy of foliage at the top. Not tuberous roots, light brown epidermis. Trunk up to 10 cm in diameter; bark smooth, reddish brown, peeling readily from trunk, latex in small quantity, light yellowish white. Young stems, glabrous, moderate olive green, internal stem colour of younger stems brilliant yellow green. Leaves alternate, stipules up to 1.0 cm long, fi liform, glabrous, caducous; petioles up to 15 cm in length, glabrous, petiole attachment to lamina basal, nonpeltate; lamina greenish without any purplish pigmentation, glabrous, ab- axial surface wax pattern smooth, veins on the adaxial lamina surface conspicuous, bright yellowish, glabrous; palmately 7–9 lobed; median lobes oblong pandurate, rarely entire, gradually widening from a narrow base to a prominently dilated apical region which abruptly narrows down and terminates in an acuminate apex, usually as long as 10 cm, base of lobes ca 0.3 cm wide, width between base of sinus and petiole-lamina junction ca 0.8 cm, lowest lobes more or less similar in outline as median lobes but smaller. Infl orescence is a monoecious raceme, as long as 15.0 cm, accompanied by one or two individual pedun- culated fl owers and an umbel with three fl owers; all parts glabrous. Bracteoles and bractlets setaceous. Bell-shaped fl owers with fi ve petals fused to one third of the length; pistillate fl owers restricted to base of the infl orescence, pedicels ca 1.2 cm long, tepal 1.25 cm long. The fuit is a subspherical three-carpellate capsule, not winged, 1.5 cm long, dehiscence septicidal. Seeds are gray, brown or mottled and oblong in shape, 1.2 cm long, with rib-like projections along the lateral edges, caruncle moderately prominent. IBERITE M., IAMONICO D. 146 ACTA BOT. CROAT. 74 (1), 2015 Iconography: Fig. 1 in HOOKER (1842, available from http://www.biodiversitylibrary. org/item/54440#page/257/mode/1up). Chromosome number: 2n = 36 (CRUZ 1968, sub M. tweedieana Muell.). Status of naturalization: M. grahamii was intentionally introduced in Italy (Agro Ponti- no area) from seeds collected in natural environment around Buenos Aires (Argentina) by an Italian emigrant in 1971 (direct evidence token by M. Iberite). M. grahamii was culti- vated in private gardens, in Agro Pontino, during the 70’s and 80’s. The plants have always produced fl owers, fruits and fertile seeds (pers. obs. by M. Iberite). The cultivated plants were eradicated during the fi rst years of the 80’s. Despite of this, from then to nowadays, the occurring of the species has been casual always deriving from seeds. The population found (Fig. 1) consists of 34 individuals of different ages (stem diameter ranging from 1.5 to 10 cm) and it has occurred on the site for about ten years. The young individuals prove that the population replaces itself. So, according to PYŠEK et al. (2004), RICHARDSON and PYŠEK (2006), RICCIARDI and COHEN (2007) M. grahamii is to be considered a naturalized alien species. Fig. 1. Manihot grahamii Hook. in Agro Pontino (Lazio region, Italy), on clay substrate along ditches near Latina. A) detail of leaves and fruits. MANIHOT GRAHAMII HOOK. IN EURASIAN AREA ACTA BOT. CROAT. 74 (1), 2015 147 Habitat and climate of the site: M. grahamii grows on clay substrate along ditches. The altitude is about 20 m a.s.l. Flowering time is June to August. The climate of the Agro Pon- tino is characterized by average annual temperatures of 15.5 °C and rainfall of 931 mm; the average temperature in January is 8.4 °C. The absolute minimum temperature was –9.2 °C (January 1985; AERONAUTICA MILITARE ITALIANA 2013). It is interesting to note that M. gra- hamii is one of the two Manihot taxa that is able to thrive in regions out of tropical and subtropical areas with occasional but predictable frost (ROGER and APPAN 1973: 7). The cli- mate conditions of the Agro Pontino area match with the ecological range of the species. Occurring in Europe and Asia: the genus Manihot was not reported in any of the Italian and European fl oras (e. g. TUTIN 1968, FIORI 1923–1929, PIGNATTI 1982, BENEDÍ, 1997, CON- TI et al. 2005, 2007, DAISIE 2008, LAMBDON et al. 2008, CELESTI-GRAPOW et al. 2009, 2010, ANZALONE et al. 2010), while it was recently recorded in Southern Italy (STINCA et al. 2014 – Manihot esculenta Crantz). Thus, the record in Agro Pontino area (Lazio region, Central Italy) represents the second record of the genus for Europe. As regard the species M. graha- mii, since no records appears in the Asian comprehensive fl oras (e. g. LI and GILBERT 2008, EDITORIAL COMMITTEE OF THE FLORA OF TAIWAN 2008, IBIN 2012, RADCLIFFE-SMITH 1986), our gathering can be considered the fi rst in the Eurasian area. As GRAHAM (l. c.) described its variety under J. loefl ingii Kunth and HOOKER (l. c.) re- ported it as partial synonym, it appears necessary to investigate this name. J. loefl ingii was published by KUNTH (1817: 107) as nomen novum pro Jatropha janipha L., avoiding the publication of the tautonym Janipha janipha (see art. 23.4 of the ICN, MCNEILL et al. 2012). Kunth (l. c.) cited four synonyms from LINNAEUS (1767: 126), JACQUIN (1763: 256–257) and LOEFLING (1758: 309, 1766: 309). The Loefl ing’s polynomial was cited by LINNAEUS (l. c.) and JACQUIN (l. c.) as synonym of Jatropha janipha L. and J. carthaginensis Jacq. respec- tively. The Linnaean name is a nomen novum pro J. carthaginensis. Since the Jacquin’s name was validly published, the Linnaean name is superfl uous and it is illegitimate under the art. 52.1 of the ICN (MCNEILL et al. 2012). The Jacquin’s name appears to be as not typifi ed. JACQUIN (l. c.) provided a short diagnosis, a long and detailed description, and the provenance (»Habitat passim Carthagenae«) and included a plate (»TAB. CLXII. Fig. I.«, image available at http://www.botanicus.org/item/31753002894886) that can be considered original material. No specimens of J. carthaginensis were found in the Jussieu’s collection at P. There is one specimen at W (barcode 0045823,) that bears a plant identifi able as J. carthaginensis. However, no date of collection is reported on the original label (at the cen- tre of the sheet), so it could be referred to a later collection (post 1763, the year of publica- tion of Jacquin’s Americanarum Historia) and could not be original material. So, the image by Jacquin is the only extant original material and it is here designated as the lectotype of the name J. carthaginensis. The comparison between the types of J. janipha L. and J. car- thaginensis Jacq. clearly shows that the name refers to the same plant and they can be con- sidered synonyms. Manihot carthaginensis (Jacq.) Müll. Arg., Prodr. [A. P. de Candolle] 15(2): 1073. 1866. ≡ Jatropha carthaginensis Jacq., Stirp. Amer., 2: 256–257. 1763. Lectotype (here designated): [Icon] TAB. CLXII Fig. I (JACQUIN, 1763). = Jatropha janipha L., Mant. Pl. : 126. 1767, nom. superfl . nom. illeg. (art. 52.1 of the ICN) ≡ Janipha loefl ingii Kunth, Nov. Gen. Sp. [H.B.K.] 2: 107. 1817, nom. nov. pro Jatro- pha janipha L. IBERITE M., IAMONICO D. 148 ACTA BOT. CROAT. 74 (1), 2015 Manihot carthaginensis is morphologically different from M. grahamii on the basis of the leaves blade shape: M. carthaginensis has leaves lobes deeply pandurate, while M. gra- hamii has entire lobes. This character is also diagnostic at section level, distinguishing the sect. Heterophyllae Pax emend. Roger & Appan (14 species) from the sect. Carthaginensis (2 species) (ROGERS and APPAN 1973). Conclusions Floristic surveys in Lazio region (Central Italy), extensive analysis of literature and her- barium investigations allowed us to fi nd a population identifi able as M. grahamii. The ge- nus Manihot is here recorded in Europe for the second time, while M. grahamii can be considered the fi rst record for the Eurasian fl ora. In order to fi x the Hooker’s name a lecto- type and an epitype are designated. For the nomenclatural purpose, the name Jatropha car- thaginensis is also lectotypifi ed. The morphological observations show that M. grahamii is clearly distinct from the related M. esculenta, M. infl ata and M. janiphoides. As regards the status of naturalization, threats and distribution, further investigations are needed to verify the possible change of the status of naturalization (invasion?) and the presence of M. graha- mii in other Italian and European regions. According to the observed and native ecological features, we can expect to fi nd this species mainly in disturbed areas (e.g. ditches or road- sides) of central and southern European countries. 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