Anales del Jardín Botánico de Madrid Vol. 67(2): 87-96 julio-diciembre 2010 ISSN: 0211-1322 doi: 10.3989/ajbm.2239 A new species of Echium (Boraginaceae) from the island of Porto Santo (Madeira Archipelago) by José Augusto Carvalho 1, Tânia Pontes 2, Maria Isabel Batista-Marques3 & Roberto Jardim 4 1 Jardim Botânico da Madeira Eng.º Rui Vieira, Caminho do Meio, 9064-512 Funchal, Portugal; 2 Rua João de Paiva 5, 3.º Direito, 1400-225 Lisboa, Portugal; 3 ESOD, Rua do Freixeiro, 4434-506 Vila Nova de Gaia, Portugal; 4 Centro de Ciências da Vida, Universidade da Madeira, 9000-390 Funchal, Portugal [email protected]; [email protected] Abstratc Resumen Carvalho, J.A., Pontes, T., Batista-Marques, M.I. & Jardim, R. Carvalho, J.A., Pontes, T., Batista-Marques, M.I. & Jardim, R. 2010. A new species from the island of Porto Santo (Madeira 2010. Una nueva especie de la isla de Porto Santo (Archipiélago Archipelago). Anales Jard. Bot. Madrid. 67(2): 87-96. de Madeira). Anales Jard. Bot. Madrid. 67(2): 87-96 (en inglés). A new species endemic from the island of Porto Santo (Madei- Echium portosanctensis J.A. Carvalho, Pontes, Batista-Marques ra Archipelago) is described as Echium portosanctensis J.A. Car- & R. Jardim se describe para la isla de Porto Santo (Achipiélago valho, Pontes, Batista-Marques & R. Jardim. Morphological stud- de Madeira). Estudios morfológicos basados en datos reproduc- ies based on reproductive and vegetative traits revealed a set of tivos y vegetativos revelan una serie de caracteres diagnósticos diagnostic characters confirming separation of E. portosancten- que confirman la separación de E. portosanctensis de otras es- sis from other recognized species at sectional level. A taxonom- pecies de su sección. Se aportan una diagnosis taxonómica, una ic diagnosis, a morphological description and illustrations of the descripción morfológica e ilustraciones para esta nueva especie. new species are provided. Images, distribution maps, ecological Se presentan imágenes, mapas de distribución, datos ecológicos data and a key for Madeiran species of Echium are also provi- y una clave para las especies de Madeira. Se discuten los carac- ded. Diagnostic characters, conservation status, threats and spe- teres diagnósticos, el estado de conservación, amenazas, y los ciation mechanisms are discussed. In addition, reports on the oc- mecanismos de especiación. También se discuten datos previos currence of E. candicans on the island of Porto Santo are also sobre la presencia de E. candicans en la isla de Porto Santo. discussed. Keywords: Pico Branco, Macaronesia, Echium nervosum, Palabras clave: Pico Branco, Macaronesia, Echium nervosum, Echium candicans, threatened species. Echium candicans, especies amenazadas. Introduction (García-Moroto & al., 2009). Among these traits, the most relevant one in Echium, concerns the acquisition Echium (Boraginaceae), with 28 endemic species, and significance of woodiness. Evolutionary studies is one of the most diverse genera in Macaronesia using molecular markers conducted by Böhle & al. (Bramwell, 1972; Santos, 1983). Endemics of this (1996) concluded that the Macaronesian taxa of genus occur in the archipelagos of Madeira, Canary Echium are the result of colonization from a single and Cape Verde, thriving in many habitats, from sea continental-herbaceous ancestor. However, this study level to 2300 m. a.s.l. Morphologically they fall in four failed to answer questions on evolutionary patterns of major growth forms. Because of this extraordinary inter-island colonization and plant habitat and eco- morphological diversity and the ability of these logical shifts (García-Moroto & al., 2009). It was only species to exploit very diverse ecological niches, Mac- recently that García-Moroto & al. (2009), by using a aronesian taxa of Echium form an ideal plant group to set of molecular markers showing higher levels of test hypothesis pertinent to the origin and evolution molecular variation, were able to bring important and of some unique traits which are common on islands new insights into the colonization history of Ma - 88 J.A. Carvalho & al. caronesian Echium, timing of differentiation, adaptive authors (Short, 1994; Bramwell, 1972) at species level radiation and evolution of woodiness. were selected for the present study. An additional set In the archipelago of Madeira species diversity is of morphological characters was chosen for better re- much less than that found in the Canary Islands. The solving the variation along geographical distribution. most recent account on plant diversity in the archipe- Photography of leaf indumentum was performed lagos of Madeira and Selvagens (Jardim & Sequei- using a binocular magnifying glass Zeiss Stemi 2000-C ra, 2008) refer two arborescent endemic species of and a photographic camera Canon PowerShot G6. Echium, namely E. candicans L.f., a high altitude (800- The image was captured using the software Canon 1500 m) species that only occurs on the island of Utilities ZoomBrowser EX 5.0 version 5.0.0.142. Madeira, and E. nervosum Dryand., restricted to alti- Distribution of studied specimens was obtained by tudes between 0 to 300 m and occurring in all main is- plotting field location data, e.g. altitude and topogra- lands of the archipelago, i.e. Madeira, Porto Santo and phy, onto a military map. The location obtained was Desertas. then transformed into 1 km2 grid based Universal Accounts of Echium L. on the island of Porto San- Transverse Mercator (UTM) . to date back to the early 20th century. Menezes (1914) and Pickering (1962) refer to E. nervosum Dryand. Results and discussion for the site of Zimbralinho. More recently, Hansen The genus Echium is now represented in Madeira (1969), Jardim & al. (1998) and Jardim & Sequeira archipelago by three endemic species: E. candicans on (2008) also reported E. nervosum to Porto Santo. the island of Madeira, E. nervosum on the islands of Costa (1946) is the first author to refer E. candicans to Madeira, Desertas and Porto Santo and E. porto- Porto Santo on the north of Gandaia. Later, Picker- sanctensis on the island of Porto Santo. These species ing (1962) refers to Costa’s (1946) observation of E. are taxonomically positioned within the Macaro - candicans. Bramwell (1972) referred to a specimen of nesian endemic sect. Virescentia [Christ ex Spr. & E. candicans L.f. collected by Hansen on Pico Castelo Hutch.] Bramwell, showing cylindrical inflorescence, which was presumed to be cultivated or a naturalized non-laterally compressed flowers, and blue or pink individual that escaped from cultivation. corolla with more or less equal lobes. Section Vires- Andrada (1974), in his contribution for the conser- centia is the largest (10 out of 28 Echium species in vation of the Madeiran flora, reported a possible no- Macaronesia) and the most widespread in Macaro - vel taxon of Echium for the island of Porto Santo, and nesia (Bramwell, 1972). Species of this section occur stated: “... Echium nervosum Ait. (fot. 15), do litoral da on all Canary Islands except Lanzarote (Bramwell, Madeira, se destaca em relação a outra espécie ou 1972), and on all islands of Madeira archipelago subespécie portosantense (fot. 16) pela nítida diferen- (Bramwell, 1972; Short, 1994; Jardim & Sequeira, ciação da cor das suas inflorescências que numa são 2008). azuis com estames brancos e noutras amareladas ou branco-rosadas, devido aos estames (filetes carmim e Misidentified species reports on Porto Santo anteras azuis)”. He points out that E. nervosum clearly differs from the taxon of the island of Porto Santo be- Reports of E. candicans for the island of Porto San- cause of the colour of their inflorescences; the former to (Costa, 1946; Pickering, 1962; Hansen in Bram - has a blue inflorescence with white stamens whereas well, 1972; Short, 1994) are not supported either by this new taxon shows yellowish or pinkish-white inflo- our studies and confirm earlier accounts by Jardim rescence due to the stamens, which have carmine fila- & al. (1998). We found no herbarium specimens of ments and blue anthers. More recently, Jardim & al. E. candicans collected by Costa (1946) and therefore (1998) confirmed the existence of Echium cf. nervo- we were unable to confirm this previous record of this sum Dryand. on the island of Porto Santo, specifically taxon for Porto Santo. Bramwell’s (1972) reference of on Pico Branco, and referred that this taxon differed E. candicans to the island of Porto Santo was based from typical E. nervosum on leaf shape, texture and on a specimen collected by Hansen in 1967 on Pico colour, as well as the colour of the inflorescence. Castelo that we were unable to find either. Moreover, in our research we came across with a herbarium spec- Materials and methods imen collected by Vieira (MADJ 05995) identified as E. candicans and reported to have been planted from Field observations and collections were carried out seeds collected on Pico Branco. Vieira (pers. com.) on the islands of Porto Santo and Madeira since 1999. wrote a letter to Hansen in 1977 asking for identifica- Herbarium specimens are deposited at MADJ. tion of this specimen. Hansen’s opinion was it was A set of morphological characters used by previous likely that this material belonged to a garden hybrid of Anales del Jardín Botánico de Madrid 67(2): 87-96, julio-diciembre 2010. ISSN: 0211-1322. doi: 10.3989/ajbm. 2239 A new species of Echium 89 E. strictum and E. virescens, i.e. E. × fastuosum. Ac- or subsessile; leaves at the base of the cyme more or cording to Hansen (Vieira, pers. com.), the original less straight but deflexed by the petiole becoming per- presence of this hybrid on Pico Branco would have pendicular or erect towards the base of the stem (Figs. been the result of dispersion of seeds originated from 1 a; 2 d). Lower leaves of the fertile stem (Fig. 1 a) 7.1- hypothetical specimens of both species in cultivation 10.6 × 1.4-2.2 cm, c.