New records of naturalised and invasive cacti (Cactaceae) from Gran Canaria and Tenerife, Canary Islands, Spain

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1 Summary: Recent field work in Gran Canaria and Tenerife (Canary Islands, Spain) yielded records for 30 alien taxa of Cactaceae that had not been reported before, either from the whole area, or from one of the islands. Out of these, 17 are considered locally naturalised and/or potentially invasive: Cylindropuntia bigelovii, C. fulgida, C. pallida, C. prolifera, C. tunicata, Echinocereus rigidissimus, Haageocereus kagenekii, Hylocereus triangularis, Opuntia basilaris, O. elatior, O. ficus-indica O. tomentosa, O. macrocentra, O. microdasys, O. pilifera, Oreocereus pseudofossulatus, Tephrocactus articulatus and Trichocereus huascha. The same applies to a rather characteristic form of O. ficus-indica that sometimes is referred to as f. amyclaea (syn.: O. megacantha). The presence of Opuntia monacantha and O. robusta, two species with a dubious status in the Canary Islands, is confirmed. Ten further taxa are considered casuals, often relics of cultivation. All taxa are illustrated, and for the naturalised and/or potentially invasive taxa additional information is provided. Two new combinations are proposed for Cylindropuntia fulgida f. mamillata and Tephrocactus articulatus f. papyracanthus. pages New records of naturalised and invasive cacti (Cactaceae) from Gran Canaria and Tenerife, Canary Islands, Spain Filip Verloove 1, Elizabeth Ojeda-Land 2, Gideon F. Smith 3,4, Alessandro Guiggi 5, Jorge Alfredo Reyes-Betancort 6, Carlos Samarín 2, Antonio González Hernández 7 & Rubén Barone 8 1. Botanic Garden of Meise, Nieuwelaan 38, B-1860 Meise, Belgium. ( filip.verloove@botanicgardenmeise.be) 2. Viceconsejería de Medio Ambiente. Gobierno de Canarias. C/ Avda. de Anaga, 35. Planta Santa Cruz de Tenerife, Canary Islands, Spain. ( eojelan@gobiernodecanarias.org; csambel@gobiernodecanarias.org) 3. Centre for Functional Ecology, Departamento de Ciências da Vida, Universidade de Coimbra, Coimbra, Portugal. ( smithgideon1@gmail.com) 4. Department of Botany, P.O. Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth, 6031 South Africa. 5. DISTAV, Polo Botanico, Università degli Studi di Genova, International Cactaceae Research Center (ICRC), Corso Dogali, 1M Genova, Italy. ( alex.guiggi@libero.it) 6. Jardín de Aclimatación de La Orotava (ICIA). C/ Retama 2, Puerto de la Cruz, Canary Islands, Spain. ( areyes@icia.es) 7. Servicio de Sanidad Vegetal. Consejería de Agricultura, Ganadería y Pesca del Gobierno de Canarias, Avda. José Manuel Guimerá 10, 3ª planta Santa Cruz de Tenerife, Canary Islands, Spain. ( agonherp@gobiernodecanarias.org) 8. C/. Eduardo Zamacois, 13-3ºA, Santa Cruz de Tenerife, Canary Islands, Spain. ( makaronesia68@yahoo.es) Zusammenfassung: Bei jüngsten Feldstudien auf Gran Canaria und Teneriffa (Kanarische Inseln, Spanien) wurden 30 nicht indigene Taxa von Cactaceae nachgewiesen, die bisher weder vom Gesamtarchipel noch von einer der beiden Inseln gemeldet waren. Von diesen werden 17 als lokal eingebürgert und / oder potenziell invasiv angesehen: Cylindropuntia bigelovii, C. fulgida, C. pallida, C. prolifera, C. tunicata, Echinocereus rigidissimus, Haageocereus kagenekii, Hylocereus triangularis, Opuntia basilaris, O. elatior, O. ficus-indica O. tomentosa, O. macrocentra, O. microdasys, O. pilifera, Oreocereus pseudofossulatus, Tephrocactus articulatus und Trichocereus huascha. Das Gleiche gilt für eine sehr charakteristische Form von O. ficus-indica, die manchmal als f. amyclaea (syn.: O. megacantha) bezeichnet wird. Zehn weitere Taxa, oft Anbaurelikte, gelten als nicht eingebürgert. Alle Taxa sind abgebildet, zu den eingebürgerten und / oder potenziell invasiven Taxa erfolgen weitere Informationen. Zwei neue Kombinationen werden vorgeschlagen: Cylindropuntia fulgida f. mamillata und Tephrocactus articulatus f. papyracanthus. 58

2 Introduction The Canary Islands, Spain, have a well-documented and rich native flora with many local, highly specialized endemic species (e.g. Bramwell, 1976; Beltrán et al., 1999). In addition, as a result of their subtropical climate, the islands are an outstanding cultivation ground for hundreds of ornamental subtropical plant species. An increasing number of these are not only well-adapted to be cultivated in the local climate, but are indeed reproducing locally without human intervention, eventually naturalising, spreading, or even becoming invasive. In past years the knowledge about these alien species has considerably increased and numerous accounts have been published (e.g. Verloove & Reyes-Betancort, 2011; Santos-Guerra et al., 2013; Scholz et al., 2013; Siverio Núñez et al., 2013; Verloove, 2013; González Montelongo et al., 2014; Santos-Guerra et al., 2014; Santos-Guerra & Reyes-Betancort, 2014; Otto & Verloove, 2016). However, some taxonomic groups are still insufficiently known. This certainly holds true for introduced succulents, despite the fact that the islands have an ideal climate that allows the persistence and acclimatization of numerous species, especially those from arid and hot habitats. The southern parts of Tenerife, for instance, have climatological circumstances comparable with those in Arizona, U.S.A. Unsurprisingly, the island houses the most important producer for cacti and succulents worldwide (Canary Cactus S.A.). Moreover, Spain is considered one of the three invasion hot spots for cacti in the world (Novoa et al., 2015; see also Essl & Kobler, 2008). Not a single species of the family Cactaceae is native to the Canary Islands, although two species have become a very familiar sight. Opuntia ficus-indica (L.) Mill. and O. dillenii (Ker- Gawl.) Haw. were introduced quite long ago, and now have invaded large parts of the islands. While O. dillenii is mostly confined to the lower altitudes, the former is omnipresent, even at higher altitudes. Eriksson et al. (1979), later merely repeated with a nomenclatural update by Acebes Ginovés et al. (2010), cited the names of nine cactus species for the Canary Islands: Austrocylindropuntia cylindrica (Lam.) Backeb., A. exaltata (Berg) Backeb., Hylocereus undatus (Haw.) Britton & Rose, Opuntia dillenii, O. maxima Mill., O. robusta H.L. Wendland, O. tomentosa Salm-Dyck, O. tuna (L.) Mill., and O. vulgaris Mill. Of these, O. maxima auct. and O. vulgaris auct. non Mill. are now referred to O. ficus-indica [although the binomial O. vulgaris has also been associated with O. monacantha (Willd.) Haw., also in the Canary Islands; see later]. Two others, O. tuna and Austrocylindropuntia cylindrica, probably refer to respectively erroneous records, or are only very locally naturalised. The remaining species have been confirmed by the authors of the present paper. In the past few years some additional species of cacti have been recorded: Cylindropuntia prolifera (Engelm.) F.M. Knuth and Opuntia microdasys (Lehm.) Pfeiff. from Fuerteventura (Verloove & Guiggi, 2013), O. leucotricha DC. from Gran Canaria, La Palma, and Tenerife (Verloove, 2013; Santos-Guerra et al., 2014), and Espostoa melanostele from Tenerife (Verloove, 2016). In the past few years some of us discovered several escaped cacti in Tenerife and Gran Canaria that had not previously been recorded in the Canary Islands. Their identities were assessed in close collaboration with two of the authors (G.F. Smith and A. Guiggi). In the present paper 30 taxa are presented and illustrated, most of them not previously reported from the Canary Islands. Their degree of naturalisation varies from ephemerals to locally, or potentially, invasive aliens. In the absence of species-specific pollinators, some of the species are able to spread by vegetative means, and their establishment could be favoured by climate change (Capdevila- Argüelles et al., 2011; Del-Arco, 2008). Several species of cacti are among the most damaging invasive plant species in the world (Novoa et al., 2015) and some, for instance the whole genus Cylindropuntia, are included in Spanish legislation on invasive alien species (B.O.E., 2013). Therefore, it is important to document any incipient invasion event of cacti, even in early stages. It is noteworthy that likely most, if not all, the plants catalogued in this paper have a cultivated origin, including from commercial nurseries with propagation facilities on the Canary Islands. It is therefore possible that, at least in some instances, the plants may not perfectly agree with botanical taxa as known from the wild (Roy Mottram, personal communication). In these circumstances, hybridisation through open pollination in fields may well have given rise to hybrids that, sometimes through introgression and backcrossing, resemble one of the parents. Materials and methods Once harvested, virtually all species of cacti are awkward to preserve as dried specimens for deposition in a herbarium, and most of the records here reported are only documented with photographs, unless otherwise stated. 59

3 The presence or absence on the islands of Gran Canaria or Tenerife was each time compared with data provided by Acebes Ginovés et al. (2010), as well as other literature sources. The paper is divided in two parts in both of which the taxa are arranged in alphabetical sequence. Naturalised and/or potentially invasive taxa are dealt with in the first part; these are treated in more detail than the taxa recorded as casuals in the second part. Each entry includes: [1.] the scientific name of the taxon (accompanied by one or more synonyms, if deemed desirable); [2.] type of chorological novelty and estimated degree of naturalisation (sensu Richardson et al., 2000); [3.] enumeration of localities; [4.] origin of the taxon; and [5.] details about its secondary distribution. Nomenclature of the taxa presented is mostly in accordance with recent insights, often based on molecular phylogenetic studies. Authorities of plant names usually follow Tropicos ( Results Part 1. Naturalised and/or potentially invasive taxa In this part those taxa are presented that either are naturalised locally, or are likely to become so in the near future. Some have at present a very limited distribution range, but have been recorded as invasive in climatologically similar areas of the world, or are found in, or near, vulnerable natural habitats on the islands. Cylindropuntia bigelovii (Engelm.) F.M. Knuth, Kaktus-ABC (Figure 1). Opuntia bigelovii Engelm., Proc. Amer. Acad. Arts 3: TENERIFE: Güímar, N, W, 113 m.s.m., Camino de Samarines E of bridge over TF-1 motorway, roadside, a single individual, , F. Verloove. A species from the southwestern U.S.A. and adjacent parts of Mexico, Cylindropuntia bigelovii is cultivated as an ornamental (Sánchez de Lorenzo Cáceres, 2000). In Güímar a single individual was observed in a dry roadside close to the Canary Cactus S.A. establishment from where it obviously had escaped. With its easily detaching stem segments that are densely covered in spines, this species resembles C. fulgida (Engelm.) F.M. Knuth var. fulgida. It is distinguished from the latter by its shrubby habit, to 1.5 m high, larger branches c. 5cm across, larger yellowish-green flowers, 3-4cm across and its smaller fruit, c. 2cm across. The fruit is densely tuberculate, dry when ripe, usually solitary, and does not form chains. Cylindropuntia bigelovii is not known as an invasive species (Novoa et al., 2015), nor has it been reported before from Europe (Essl & Kobler, 2008). In Güímar, C. bigelovii obviously is a recent escape and cannot be classified as naturalised yet. However, like other species from this genus, it certainly has the potential to establish and spread to the nearby nature reserve of Malpaís de Güímar. Cylindropuntia fulgida (Engelm.) F.M. Knuth, Kaktus-ABC (Figure 2). f. mamillata (Schott ex Engelm.) Guiggi & Verloove comb. nov. Basionym: Opuntia mamillata Schott ex Engelm., Proc. Amer. Acad. Arts 3: C. fulgida var. mamillata (Schott ex Engelm.) Backeb., Cactaceae Handb. Kakteen. Pereskioideae Opuntioideae 1: Opuntia fulgida Engelm., Proc. Amer. Acad. Arts 3: var. mamillata (Schott ex Engelm.) J.M. Coult., Contr. U.S. Natl. Herb. 3(7): TENERIFE: Guía de Isora: Playa de San Juan, N, W, 48 m.s.m., stony slope next to the sea cliffs, numerous individuals, , F. Verloove.; idem, , E. Ojeda-Land et al.; Santiago del Teide: Puerto de Santiago, N, W, 51 m.s.m., barranco de Santiago close to calle Seis, rocky slope of ravine, c. 50 individuals, , F. Verloove; idem, , F. Verloove (BR). Cylindropuntia fulgida is a species originally native to Mexico and adjacent parts of the southwestern U.S.A. It is widely cultivated as an ornamental (e.g. Sánchez de Lorenzo Cáceres, 2000) and readily escapes, its stem segments easily detaching and rooting. It is often considered an undesirable, highly invasive species, for instance in Australia (Chinnock, 2015) and South Africa (Walters et al., 2011; see also Novoa et al., 2015). It had not been recorded before from Europe (Essl & Kobler, 2008). In Tenerife two populations were recently detected. In Playa de San Juan, numerous individuals have been observed on a dry, sun-exposed 60

4 Figure 1. Cylindropuntia bigelovii, Güímar (TF), dry roadside, November Figure 2. Cylindropuntia fulgida, Puerto de Santiago (TF), slope of ravine, January Figure 3. Cylindropuntia pallida, El Médano (TF), stony slope of ravine, June Spines are white throughout. slope close to the sea cliffs. In this locality it obviously persists from an abandoned plantation. However, it evidently reproduces and appears very prolific. Further local expansion of the population is very likely. A smaller population with c. 50 individuals was discovered in Puerto de Santiago on volcanic rocks bordering a ravine. In this locality, C. fulgida also looks well-established and will probably start spreading in the near future. It Figure 4. Cylindropuntia prolifera, Punta del Hidalgo (TF), September grows with C. tunicata (Lehm.) F.M. Knuth, another potentially invasive species. The plants found in Tenerife have stem segments appearing spineless or nearly so from afar, exposing strongly mamillate tubercles, a trait of var. mamillata (Pinkava, 2003a). A taxonomic rank lower than varietas for such minor variation, however, seems more appropriate. A new combination, as forma, is proposed here. 61

5 Figure 6. Cylindropuntia tunicata, new growth with typical pinkish-brownish spines, Puerto de Santiago (TF), slope of ravine, January Figure 5. Cylindropuntia tunicata, Puerto de Santiago (TF), slope of ravine, January Figure 7. Echinocereus rigidissimus, Playa de San Juan (TF), stony slope close to sea cliffs, May Photograph by J.A. Reyes-Betancort. Figure 9. Hylocereus triangularis, Valle de San Lorenzo (TF), dry river bed, January Figure 8. Haageocereus kagenekii, El Médano (TF), stony slope of ravine, January Photograph by E. Ojeda-Land. 62

6 Most of the plants observed belong to a commonly cultivated morphotype with crested stems, which is often referred to as the boxing-glove cactus. Cylindropuntia pallida (Rose) F.M. Knuth, Kaktus-ABC (Figure 3). Opuntia pallida Rose, Smithsonian Misc. Collect. 50: = Cylindropuntia rosea auct. non (DC.) Backeb., Cactaceae Handb. Kakteen. Pereskioideae Opuntioideae 1: TENERIFE: Granadilla de Abona: Hoyas de Doña María, Las Arenas-El Médano, N, W, 60 m.s.m. to N, W, 54 m.s.m., , E. Ojeda- Land et al.; Granadilla de Abona: La Mareta, 28º N, 16º W, 11 m.s.m., , E. Ojeda-Land et al.; Buenavista del Norte: Costa de El Rincón, 28º N, 16º W, 15 m.s.m., , E. Ojeda- Land et al. In El Médano a huge population is naturalised and spreading from an abandoned, not well delimited cultivation experiment. In this locality numerous cacti have been observed (Opuntia spp., Cylindropuntia spp., Cleistocactus spp., Oreocereus spp., etc.), some of them showing invasive behavior. In La Mareta a few naturalised individuals were observed that escaped from a garden close to the road TF-643, and in similar circumstances five individuals were recorded in Costa de El Rincón in Buenavista del Norte. Cylindropuntia pallida has long been known as C. rosea. The type of the latter, however, was shown to belong to C. imbricata (Haw.) F.M. Knuth (Laguna et al., 2013). This species is doubtfully distinct from C. tunicata and its nomenclature is very confusing. The neotype of C. imbricata is the painting of Haworth s plant by Duncanson at Kew, designated by Hunt & Taylor (2006), which may as well depict O. subulata. Haworth s description of C. imbricata calls for it to be imbricate and tessellate, which C. imbricata auct. is certainly not. Thus an early misapplication of the name took place, probably by Engelmann, which means that C. rosea should have been the correct name for what is called C. imbricata today (Roy Mottram, personal communication). Cylindropuntia prolifera (Engelm.) F.M. Knuth, Kaktus-ABC (Figure 4). Opuntia prolifera Engelm., Amer. J. Sci. Arts, ser. 2 14(42): New to the flora of Tenerife. Previously reported from Fuerteventura (Verloove & Guiggi, 2013) and Lanzarote where a project of eradication has been conducted in La Triguera, Tenegüime ( =Noticias&idTema=17&idCont=12077). Other target species of this eradication program were Cylindropuntia kleiniae (DC.) F.M. Knuth, Opuntia engelmannii Salm-Dyck ex Engelm., and O. leucotricha. All were deliberately introduced initially, but only C. prolifera was able to spread. TENERIFE: San Cristóbal de La Laguna: Punta del Hidalgo, , F. Verloove; Granadilla de Abona: Hoyas de Doña María, Las Arenas-El Médano, N, W, 60 m.s.m. to N, W, 54 m.s.m., , E. Ojeda-Land et al.; San Miguel de Abona: Amarilla Golf, 28º N, 16º W, 20 m.s.m., , E. Ojeda- Land. This species is restricted to a relatively small area in Mexico (Baja California) and the U.S.A. (California). It is said to be a hybrid of two Mexican species, Cylindropuntia alcahes (F.A.C. Weber) F.M. Knuth and C. cholla (F.A.C. Weber) F.M. Knuth (Pinkava, 2003a). Outside its native area it is planted as an ornamental, although perhaps not widely so; for instance, it is not mentioned by Sánchez de Lorenzo Cáceres (2000). In Punta del Hidalgo in Tenerife a small population of Cylindropuntia prolifera was recorded in In El Médano, also in Tenerife, a huge population has naturalised and is spreading from an abandoned, not well controlled cultivation experiment. Close by, in Amarilla Golf, only two individuals were observed growing on a volcanic rocky slope near to the golf court. Although not mentioned as an invasive species by Novoa et al. (2015), Cylindropuntia prolifera is known as such, at least in southern Australia where it is quite widespread (Chinnock, 2015). It is reminiscent of C. spinosior (Engelm.) F.M. Knuth, and the two species may have been confused. The latter is distinguished by its white spines and yellow to orange fruits, as opposed to the brownish spines and green fruits of C. prolifera. Cylindropuntia tunicata (Lehm.) F.M. Knuth, Kaktus-ABC (Figures 5 6). Opuntia tunicata (Lehm.) Pfeiff., Enum. Diagn. Cact Cactus tunicatus Lehm., Nova Acta Phys.-Med. Acad. Caes. Leop.-Carol. Nat. Cur. 16:

7 TENERIFE: Granadilla de Abona: Hoyas de Doña María, Las Arenas-El Médano, N, W, 60 m.s.m. to N, W, 54 m.s.m., , E. Ojeda- Land et al.; Santiago del Teide: Puerto de Santiago, N, W, 51 m.s.m., barranco de Santiago close to calle Seis, rocky slope of ravine, ca individuals, , F. Verloove; Granadilla de Abona: San Isidro, N, W, 170 m.s.m., calle Cuevas de Choportada, rough ground, c individuals, , F. Verloove; Santiago del Teide: Puerto de Santiago, N, W, 51 m.s.m., barranco de Santiago close to calle Seis, rocky slope of ravine, , F. Verloove (BR); Granadilla de Abona: San Isidro, N, W, 172 m.s.m., S of calle el Almendro, dry stony slope, scattered individuals, , F. Verloove; Granadilla de Abona: San Isidro, N, W, 181 m.s.m., on the verge of barranco del Conde, few individuals, , F. Verloove. Cylindropuntia tunicata is a native species in a small area in Texas, U.S.A., and adjacent parts of Mexico. It is also known from Chile and Ecuador in South America (Pinkava, 2003a). Elsewhere it is widely grown as an ornamental, also in Europe (see for example Sánchez de Lorenzo Cáceres, 2000). In Tenerife several small populations were recently detected. In El Médano this species is naturalised in a gravelly riverbed along with many other cacti, resulting from an abandoned cultivation experiment. In Puerto de Santiago the species grows on volcanic rocks of a ravine close to houses, along with C. fulgida. In San Isidro it was found in several subpopulations, in disturbed xeric as well as in more natural habitats. In all these localities C. tunicata appears well-established and a future local expansion is predicted, especially since the stem segments easily become detached and root where they fall. This species is a known invader, for instance in Australia (Chinnock, 2015; Novoa et al., 2015), but it was not previously reported from Europe according to Essl & Kobler (2008). Guillot et al. (2008), however, have since reported it from several localities in Spain and it is also known from Italy (Guiggi, 2008). Previous claims in South Africa proved to be referable to C. pallida (Rose) F.M. Knuth (Walters et al., 2011). Cylindropuntia tunicata closely resembles C. pallida and the two species may have been confused in the past. It is distinguished, however, by its spines that are pinkish or brownish in young growth (vs white), by its yellowish brown corollas (vs rose-red) and by less numerous spines per areole (4 7 vs 7 14). Echinocereus rigidissimus (Engelm.) F. Haage, Special Preisverz (Figure 7). TENERIFE: Guía de Isora: Playa de San Juan, N, W, 27 m.s.m., , J.A. Reyes-Betancort et al. This species is native to Arizona and New Mexico (U.S.A.) and Chihuahua and Sonora (Mexico) (Zimmerman & Parfitt, 2003). It is widely grown as an ornamental, also in mainland Spain (Sánchez de Lorenzo Cáceres, 2000). In Tenerife, in Playa de San Juan, two individuals were found growing on the edge of a coastal cliff, in gravelly, sandy soils. To our knowledge, this species has not yet been recorded in the wild beyond its native distribution range. It is, however, cultivated as an ornamental (especially its subsp. rubispinus (G. Frank & A.B. Lau) N.P. Taylor (Taylor, 1989). Haageocereus kagenekii (C.C.Gmel) Mottram, The Cactician 7: (Figure 8). Cactus kagenekii C.C.Gmel., Hortus magni ducis badensis carlsruhanus: (Fig. 3) Cereus kagenekii (C.C.Gmel.) K.Schum., Gesamtbeschreibung der Kakteen (2): 66. (15 May) = Cereus pseudomelanostele Werderm. & Backeb., Neue Kakteen = Haageocereus pseudomelanostele (Werderm. & Backeb.) Backeb., Kaktus-ABC = Haageocereus multangularis (Haw.) F. Ritter, Kakteen Südamer. 4: TENERIFE: Granadilla de Abona: Hoyas de Doña María, Las Arenas-El Médano, N, W, 60 m.s.m. to N, W, 54 m.s.m., , E. Ojeda- Land et al. As noted above this species is associated with an abandoned, not well managed cultivation experiment in El Médano. Several individuals were detected in the surrounding native vegetation that is dominated by Euphorbia balsamifera Aiton and Lycium intricatum Boiss., which indicates a local naturalisation event. 64

8 Figure 10. Opuntia basilaris, Güímar (TF), volcanic slope, January Figure 11. Opuntia elatior, Buenavista del Norte (TF), rough ground, March Flowering cultivated individual, growing close to the escaped non-flowering plants. Photograph by J.A. Reyes-Betancort. Figure 13. Opuntia ficus-indica f. amyclaea (O. megacantha), Ayagaures (GC), stony slope, November Figure 12. Opuntia ficus-indica O. tomentosa, Masapeses (GC), under Eucalyptus canopy, November Haageocereus kagenekii is not known as an invasive species (Novoa et al., 2015), nor has it been reported before from Europe (Essl & Kobler, 2008). It is widely grown as an ornamental, also in mainland Spain (Sánchez de Lorenzo Cáceres, 2000; as H. multangularis (Haw.) F. Ritter). Note that this species is still sometimes treated as Haageocereus pseudomelanostele. However, Mottram (2014) published the combination Figure 14. Opuntia macrocentra, Playa de San Juan (TF), stony slope, November

9 Figure 15. Opuntia macrocentra, detail of cladodes, Playa de San Juan (TF), stony slope, November Figure 16. Opuntia microdasys, El Médano (TF), dry riverbed, June Photograph by A. González. Figure 17. Opuntia monacantha, Mesa de Mar (TF), roadside, January Figure 18. Opuntia pilifera, San Agustín (GC), stony slope, November Figure 19. Opuntia robusta, Puerto de la Cruz (TF), rough ground, November Figure 20. Oreocereus pseudofossulatus, El Médano (TF), dry riverbed, June

10 H. kagenekii for the species, the earliest name of which is Cactus kagenekii C.C.Gmel. Hylocereus triangularis (L.) Britton & Rose, Contr. U.S. Natl. Herb. 12(10): (Figure 9). Cactus triangularis L., Sp. pl. 1: TENERIFE: Arona: Valle de San Lorenzo, N, W, 402 m.s.m., barranco de Chija N of TF-28, rocky slope of ravine, a single individual, , F. Verloove. A native of the Caribbean, Hylocereus triangularis is widely cultivated in the subtropics, either as an ornamental, or for food ( dragon fruit ). This species, as well as several others from this genus, are grown in the Canary Islands (Hernández et al., 2013), although H. undatus is probably by far the most widespread. The latter is also the only species of the genus that has so far been recorded outside of cultivation (Acebes Ginovés et al., 2010). The single plant found in a ravine in Valle de San Lorenzo in Tenerife differs from H. undatus in having stems that are not horny-angled with areoles with numerous spines (6 8), and its smaller stature with stems only c. 3 4cm across (Britton & Rose, ). Hybridisation, either artificial or spontaneous, may have blurred species boundaries in this genus resulting in plants found in the wild in Europe exhibiting intermediate traits. To the best of our knowledge, Hylocereus triangularis has only been recorded before in Europe in Sicily (Guiggi, 2010). Although only a single individual was found in Tenerife, a future naturalisation cannot be excluded since its ecology and biology typically resemble that of H. undatus, a known invasive species (Novoa et al., 2015). Opuntia basilaris Engelm. & J.M. Bigelow, Proc. Amer. Acad. Arts 3: (Figure 10). TENERIFE: Güímar, N, W, 94 m.s.m., on the verge of the nature reserve Malpaís de Güímar, close to the Canary Cactus S.A. plant, on volcanic soil, a single clone, , F. Verloove 12747; Güímar, N, W, 114 m.s.m., on the verge of the nature reserve Malpaís de Güímar, close to the Canary Cactus S.A. plant, on volcanic soil, two small populations of c. 8 and 9m², , F. Verloove. Opuntia basilaris is native to a relatively small area in the southwestern U.S.A. and the adjacent Sonoran Desert in Mexico. It is grown as an ornamental, although probably not very widely so (see for example Hunt, 1989). As far as we could establish, the species had not been recorded before outside of cultivation. In Tenerife, scattered small populations were discovered on volcanic slopes on the verge of the Reserva Natural Especial del Malpaís de Güímar, close to the Canary Cactus S.A. plant, from where it probably escaped. Opuntia basilaris is somewhat reminiscent of O. microdasys with which it shares a low-growing habit, and the cladodes having numerous spineless areoles densely packed with short glochidia (Smith et al., 2011). It differs, however, by its cladodes being bluish-green with reddish-brown glochids, and its purplish-red corollas. The populations currently found in Tenerife may include or even pertain to hybrids with the similar O. rufida Engelm. (Roy Mottram, personal communication). Opuntia elatior Mill., Gard. Dict. ed. 8, (Figure 11). = O. bergeriana F.A.C.Weber ex A.Berger, Gard. Chron. III, 1904(1): TENERIFE: Buenavista del Norte: road to Costa de El Rincón, 28º N 16º W, 37 m.s.m., , J.A. Reyes-Betancort. Opuntia elatior is native to Mesoamerica, from Venezuela to the Antilles (Bravo-Hollis & Arias, 2011). It has been recorded as an alien from continental Spain in Valencia (Guillot et al., 2008; Guillot et al., 2014) and the Balearic Islands (Serapio et al., 2016), twice as O. bergeriana. In Buenavista del Norte in Tenerife, only two small individuals were discovered near to the road, in a waste place that has been partially used as a garbage dump for cacti. Cladodes were only 15cm long and flowers were red. Opuntia elatior has been reported before as an invasive alien, for instance from Australia (Novoa et al., 2015). In Indonesia, India, and South Africa it was introduced in the 19 th century and quickly spread. As a result of biological control, however, these invasions have much decreased lately. It is apparently not very widespread in cultivation; it was not mentioned, for instance, in Hunt (1989) or Sánchez de Lorenzo Cáceres (2000). In Europe, 67

11 O. elatior has also been reported from Italy (Guiggi, 2008). Opuntia ficus-indica (L.) Mill. O. tomentosa Salm-Dyck. (Figure 12). GRAN CANARIA: Arucas: Masapeses, urbanización El Caserío, N, W, 374 m.s.m., GC-43 between Teror and Visvique, half-shady roadside, under Eucalyptus canopy, frequent, , F. Verloove. TENERIFE: San Cristóbal de La Laguna: La Laguna, barranco de Santos E of TF-13, N, W, 448 m.s.m., gravelly riverbed, frequent, , F. Verloove; Tegueste: El Socorro, barranco de Las Cuevas, N, W, 282 m.s.m., woody slope, frequent, , F. Verloove; Santa Úrsula: La Quinta, N, W, 185 m.s.m., stony slope, few plants, , F. Verloove; Buenavista del Norte: Los Carrizales, stony slopes with the two parental species, N, W, , J.A. Reyes-Betancort. Putative hybrids of Opuntia ficus-indica and O. tomentosa are increasingly recorded in the Canary Islands. It is uncertain whether or not they arose spontaneously or as a result of a deliberate, artificial crossing. However, in all populations in Gran Canaria and Tenerife where it was recorded recently, both putative parental species were found growing within the flight distance of an insect or bird. This hybrid is apparently known from Mexico from prehistorical times (R. Mottram, personal communication), wherever the two species were cultivated together (see also Smith & Figueiredo, 2012 on the species in South Africa). The hybrid plants seen in the Canary Islands are more or less intermediate between both parent species, although in most characters they are closer to O. tomentosa. With the latter they share the tree-like habit and the velvety epidermis of the cladodes. However, in the hybrid the cladodes are much less greyish in appearance, and they are very spiny, features typical of forms of the other putative parent, O. ficus-indica. Opuntia elisae D. Guillot & Van der Meer ex D. Guillot has been described from continental Spain, and probably also has Opuntia ficus-indica and O. tomentosa as parents (Guillot & Van der Meer, 2004; Ferrer-Gallego et al., 2014). However, we refrain from using this name for the plants currently found in the Canary Islands since the latter markedly differ, for instance in having velvety cladodes. O. elisae, with glabrous stem segments, obviously is closer to O. ficus-indica; moreover, the other putative parent is O. tomentosa var. hernandezii (DC.) Bravo (syn.: O. hernandezii DC.). Several perfectly established populations were discovered in the past years, both in Gran Canaria and Tenerife (see above). It usually grows on rocky, often wooded, slopes, and may well have been overlooked elsewhere in the Canary Islands. In the Canary Islands Opuntia ficus-indica and O. tomentosa are both considered invasive species (Acebes Ginovés et al., 2010) and the same may apply to the hybrid between them. Opuntia tomentosa and O. ficus-indica, both polyploids (Pinkava, 2002), are also likely to be of allopolyploid origin (Majure et al., 2012). Opuntia ficus-indica (L.) Mill., Gard. Dict. (ed. 8) No (Variant illustrated, see Figure 13). = O. vulgaris Ten., Syll. Fl. Neap , non Mill. = O. ficus-barbarica A. Berger, Monatsschr. Kakteenk. 22: The taxonomy and nomenclature of this most widely spread and highly invasive species of Opuntia in the Canary Islands are rather complicated. Acebes Ginovés et al. (2010) accept both O. maxima Mill. and O. vulgaris Mill., while both are often considered synonyms of, respectively, O. ficus-indica and O. monacantha, or even of O. humifusa (Guiggi, 2008). O. vulgaris is the earliest replacement name for Cactus opuntia L. in Opuntia in order to avoid the tautonym. That in turn is considered to be the same as Cactus ficus-indica L. Using O. vulgaris for the plant correctly called O. humifusa was a misapplication, curiously started by Miller himself who illustrated O. humifusa under the wrong name in his Icones (Miller, 1768; Roy Mottram, personal communication). Opuntia ficus-indica itself is a variable species, perhaps rather a complex of closely related entities of contested taxonomic validity. This species is technically a cultivar, having been bred for centuries. Its variability in the Canary Islands has not been studied yet in depth, but surely more than one taxon is present, the most notable probably being the following. Opuntia ficus-indica f. amyclaea (Ten.) Schelle, Handb. Kakteenkult Nomenclature according to Kiesling (1998). = O. megacantha Salm-Dyck, Hort. Dyck (Figure 12). = O. maxima Salm-Dyck, Cact. Hort. Dyck , non Mill. 68

12 Figure 22. Tephrocactus articulatus, Playa de San Juan (TF), stony slope, November Figure 21. Oreocereus pseudofossulatus in flower, El Médano (TF), dry riverbed, June Figure 24. Trichocereus huascha (in the background Cylindropuntia pallida), El Médano (TF), stony slope of ravine, June Figure 23. Tephrocactus articulatus, in flower, Playa de San Juan (TF), stony slope, June Large populations of this species were discovered on a sunny slope near Ayagaures in Gran Canaria in 2015 and in an abandoned quarry in Santiago del Teide in Tenerife in It is also relatively widespread in the Anaga mountains. These records seem to confirm the previous assumption of Marrero et al. (1995). Compared with Opuntia ficus-indica it has oblong to suborbicular, glaucous-pruinose, distinctly flattened cladodes that are always spiny. Molecular data seem to suggest that it probably is nothing else than the wild progenitor of domesticated Figure 25. Cereus hildmannianus, El Médano (TF), dry riverbed, June Photograph by A. González. 69

13 Figure 26. Cleistocactus hyalacanthus, Playa de San Juan (TF), stony slope, June Figure 27. Cleistocactus strausii, Playa de San Juan (TF), stony slope, June Figure 29. Neogriseocereus pruinosus, Playa de San Juan (TF), stony slope, November O. ficus-indica (Labra et al., 2003). Other authors, however, accept it as a species distinct from O. ficus-indica, based on morphometric analyses (Reyes-Agüero et al., 2005). Figure 28. Isolatocereus dumortieri, El Médano (TF), dry riverbed, June Photograph by A. González. Opuntia macrocentra Engelm., Proc. Amer. Acad. Arts 3: (Figures 14 15). Opuntia violacea Engelm. ex B.D. Jacks., Index Kew. 2:

14 var. macrocentra (Engelm.) L.D. Benson, Cacti Arizona (ed. 3): TENERIFE: Guía de Isora: Playa de San Juan, N, W, 48 m.s.m., stony slope next to the sea cliffs, numerous individuals, , F. Verloove; idem, , E. Ojeda-Land et al. Originally native to the southern United States (Arizona, New Mexico, Texas) and Mexico (Chihuahua, Coahuila, Sonora), Opuntia macrocentra is sometimes grown as an ornamental in other warm and dry parts of the world (see for example Hunt, 1989; Sánchez de Lorenzo Cáceres, 2000). Although, with its purple stem segments with spines of up to 12 or even 17cm long (Pinkava, 2003b), it is visually very garden-worthy, this species is less frequent in cultivation than other members of Opuntia series Phaeacanthae Britton & Rose. Opuntia macrocentra has not been recorded outside of cultivation, apparently, although in South Africa the probability of a future naturalisation was envisaged (Walters et al., 2011). In Playa de San Juan in Tenerife, Opuntia macrocentra occurs in numerous subpopulations in a relatively small area where it appears well established. Opuntia violacea Engelm. (1848) is the correct name for this plant if the paper in which it was published by Emory is not to be considered provisional only. Hunt et al. (2006) unilaterally deemed it so, but the Emory paper has never actually been proposed for inclusion in the list of suppressed works (Roy Mottram, personal communication). Opuntia microdasys (Lehm.) Pfeiff., Enum. Diagn. Cact (Figure 16). Cactus microdasys Lehm., Index sem. (Hamburg) New to the flora of Tenerife. Previously reported from Fuerteventura (Verloove & Guiggi, 2013) and La Palma (Mirador del Time) (Salas Pascual, 2010). TENERIFE: Arico: Abades, N, W, 9 m.s.m., barranco N of the village, stony slope close to the Iglesia del Sanatorio de Abades, a single individual, , F. Verloove; Granadilla de Abona: Hoyas de Doña María, Las Arenas-El Médano, N, W, 63 m.s.m., , E. Ojeda- Land et al.; Buenavista del Norte, road to Costa de El Rincón, 28º N, 16º W, m.s.m., , J.A. Reyes-Betancort. A native of Mexico, Opuntia microdasys is widely cultivated as a popular and attractive ornamental. It is often recorded as an escape from cultivation, in Europe at least in France, Italy, Portugal, and Spain (Essl & Kobler, 2008; Novoa et al., 2015). In the Canary Islands it had only been reported before from a single locality in Fuerteventura (Verloove & Guiggi, 2013) and from La Palma where initially there was some doubt with regard to its identity (Salas Pascual, 2010). One of us (J.A. R.-B.) also knows O. microdasys from Lanzarote where two small populations were naturalised near the road to Playa Quemada and in the village of Nazaret. In Abades in Tenerife a single individual was seen in 2016 where it can hardly be classified as naturalised. However, in El Médano its naturalisation has been observed and it could well become an invader in the future, as is the case in Australia and South Africa (Walters et al., 2011; Novoa et al., 2015). In Buenavista del Norte one individual was observed growing in the inclined ditch of the road. In this locality other species of Opuntia (one individual of O. pilifera, one of O. lindheimeri Engelm., and two of O. lindheimeri var. linguiformis (Griffiths) L.D. Benson) compete with Arundo donax L., colonising the slopes and the water course of the adjacent shallow ravine. None of these, however, can be classified yet as genuinely naturalised in that location. Opuntia microdasys is a variable species. In El Médano two more or less distinct forms are present. In some plants glochids are yellow or whitish, while in others they are reddish-brown. The latter is sometimes distinguished as subsp. rufida (Engelm.) U. Guzmán & Mandujano (syn.: O. rufida Engelm.). However, glochid colour in O. microdasys s.str. is a variable character and genuine O. rufida is a closely related, but quite different species (Pinkava, 2003b). Schumann was the earliest to make the combination O. microdasys var. rufida, with O. rufida Engelm. as its basionym. It was Berger who was the first to apply the name O. microdasys var. rufida to a brown-glochided form of O. microdasys in cultivation at La Mortola, Italy, and explicitly excluding the type of O. rufida Engelm. He therefore created a later homonym of Schumann s name a different entity, and therefore illegitimate. He can, however, be deemed to have established the cultivar name O. microdasys Rufida. The name subsp. rufida (Engelm.) U. Guzmán & Mandujano is validly published, but it is another superfluous synonym of 71

15 O. rufida Engelm. No valid and legitimate botanical name currently exists for the brown-spined form of O. microdasys (Roy Mottram, personal communication). Opuntia monacantha (Willd.) Haw., Suppl. pl. succ (Figure 17). Cactus monacanthos Willd., Enum. pl [1814]. Opuntia vulgaris Britton & Rose non Mill., Cact. 1: Confirmation for the flora of the Canary Islands. TENERIFE: San Cristóbal de La Laguna: Tejina, charcas de Tejina, N, W, 155 m.s.m., talus slope, scattered individuals, , F. Verloove; idem., , J.A. Reyes-Betancort; Puerto de la Cruz, La Montañeta, N, W, 306 m.s.m., rough ground, c individuals, , F. Verloove; Santa Úrsula: La Quinta, close to calle Codeso, N, W, 191 m.s.m., shrubland, small population, , F. Verloove; Tacoronte: Mesa del Mar, calle Mesa del Mar, N, W, 252 m.s.m., small population, , F. Verloove. This South American species (Argentina and Brazil) is widely cultivated as an ornamental, also in the Canary Islands, although it was surprisingly omitted by Sánchez de Lorenzo Cáceres (2000). Acebes Ginovés et al. (2010) do not cite Opuntia monacantha for the Canarian flora. Their citation of O. vulgaris, however, most likely refers to O. monacantha (see Kunkel, 1972). O. vulgaris is a confusing name; according to Leuenberger (1993) it is conspecific with O. ficus-indica, while Hunt et al. (2006) wrongly consider it a synonym of O. humifusa (Raf.) Raf. (see above). In Tenerife, Opuntia monacantha was observed in several localities in the northern part of the island, usually in small numbers and in the vicinity of houses. Most populations probably represent relics of former cultivation, or are established from discarded garden waste. The species seems much less vigorous than the superficially similar, but much larger-growing, O. ficus-indica. However, it is one of the most widely spread invasive cacti worldwide (Novoa et al., 2015). For instance, it is a serious invader in Australia, India, Madagascar, Mauritius, South Africa, and Sri Lanka, although, at least in some countries, it has decreased since the introduction of a cochineal species, Dactylopius ceylonicus (Walters et al., 2011). Opuntia monacantha is easily separated by its rather thin, pliable, and shiny cladodes. It often has a somewhat drooping appearance, doubtlessly as a result of the large fruits. Opuntia pilifera F.A.C. Weber, Dict. Hort (Figure 18). GRAN CANARIA: San Bartolomé de Tirajana: San Agustín, N, W, 48 m.s.m., urbanización Colegio Arenas Sur, dry stony slope, a large clone, , F. Verloove; San Bartolomé de Tirajana: Bahía Feliz, N, W, 10 m.s.m., roadside GC-500, a single clone (cultivated in central reservation,), , F. Verloove; TENERIFE: Buenavista del Norte: Costa de El Rincón, 28º N, 16º W, 15 m.s.m., , E. Ojeda-Land et al.; idem, , J.A. Reyes-Betancort. Opuntia pilifera is a Mexican species that has been reported from Puebla and Oaxaca. Outside of its native distribution range it is widely cultivated as an ornamental in warm-temperate parts of the world, also in southern Europe, although it is surprisingly omitted by, for instance, Hunt (1989) and Sánchez de Lorenzo Cáceres (2000). It has been reported in the wild from France (Tison & de Foucault, 2014), Italy (Manni & Guiggi, 2015), Spain (Guillot & Lodé, 2009; Sánchez-Gullón et al., 2014) and Malta (see: It is here reported for the first time from the Canary Islands. In Gran Canaria single clones were encountered in two nearby localities, while in Tenerife six clones have become established on the slope of a ravine, as escapes from the adjacent living fence of a cactus nursery. Opuntia pilifera is a characteristic species. Its glabrous cladodes are obovate to suborbicular, and large (up to 35cm long); the areoles are covered with whitish or yellowish, silky trichomes; and its flowers are pinkish, turning purplish (Arias et al., 2012). Opuntia robusta J.C. Wendl., Cat. Hort. Herrenh (Figure 19). Confirmation for the flora of the Canary Islands. TENERIFE: Puerto de la Cruz, SW of calle Sarasate, N, W, 127 m.s.m., rough ground, a single large clone of c. 20 m², and , F. Verloove; 72

16 Figure 30. Pilosocereus pachycladus, Playa de San Juan (TF), stony slope, November Figure 31. Thelocactus hastifer, Playa de San Juan (TF), stony slope, November Figure 33. Trichocereus peruvianus, Puerto de la Cruz (TF), roadside slope, January Figure 32. Trichocereus bridgesii, Chayofa (TF), vacant lot in residential area, November Granadilla de Abona: Hoyas de Doña María, Las Arenas-El Médano, N, W, 62 m.s.m., , E. Ojeda-Land et al.; Buenavista del Norte: Costa de El Rincón, 28º N, 16º W, 15 m.s.m., , J.A. Reyes-Betancort. This Mexican species has been reported from Gran Canaria, La Palma, and Tenerife in the Canary Islands (Acebes Ginovés et al., 2010). However, it is rather rarely grown as an ornamental Figure 34. Trichocereus vollianus, Playa de San Juan (TF), stony slope, November

17 and most claims may refer to O. ficus-indica f. amyclaea (syn.: O. megacantha) and other forms of this species. The authors have only seen it in three naturalised populations in Tenerife. Compared with O. ficus-indica, cladodes in O. robusta are larger and very glaucous, almost orbicular and its areoles are widely scattered and somewhat depressed. In the El Médano locality, some clones of a putative O. robusta hybrid have also been observed. Opuntia robusta is an invasive weed in several countries, including Australia, Botswana, and South Africa (Walters et al., 2011; Novoa et al., 2015). In Europe it is only rarely reported in the wild. Guiggi (2014) provides details for Italy. Oreocereus pseudofossulatus D.R. Hunt, Bradleya 9: (Figures 20 21). = Cleistocactus fossulatus Mottram, Chileans 13(43): [non Pilocereus fossulatus Labour., Rev. Hort. ser. 4 4(2): ; Oreocereus fossulatus (Labour.) Backeb., Kakt.-Freund 3(2): = Oreocereus celsianus (Salm-Dyck) Riccob.] TENERIFE: Granadilla de Abona: Hoyas de Doña María, Las Arenas-El Médano, N, W, 54 m.s.m. to N, W, 50 m.s.m., , , , , E. Ojeda-Land et al. As mentioned above the presence of Oreocereus pseudofossulatus in El Médano arose from an abandoned, not well delimited cultivation experiment. Birds that feed on the fleshy fruits could enhance its expansion, although, at present, it is only locally naturalised. Oreocereus pseudofossulatus is not known as an invasive species (Novoa et al., 2015), nor has it been reported before from Europe (Essl & Kobler, 2008). It is often grown for ornament. Tephrocactus articulatus (Pfeiff.) Backeb., Cactus (Paris) 38: (Figures 22 23). Opuntia articulata (Pfeiff.) D.R. Hunt, Bradleya 5: f. papyracanthus (Phil.) Guiggi & Verloove comb. nov. Basionym: Opuntia papyracantha Phil., Gartenflora 21: Synonym: Tephrocactus articulatus (Pfeiff.) Backeb. var. papyracanthus (Phil.) Backeb., Cactus (Paris) 38: TENERIFE: Guía de Isora: Playa de San Juan, N, W, 48 m.s.m., stony slope next to the sea cliffs, numerous individuals, , F. Verloove; idem., , E. Ojeda-Land et al. Tephrocactus articulatus, which is native to Argentina, is sometimes grown as an ornamental in warm and dry areas of the world. Outside of its native area it has been reported as an invasive alien in South Africa and Namibia (Walters et al., 2011). In Playa de San Juan numerous individuals of Tephrocactus articulatus are found growing on bare, sun-exposed slopes close to the sea cliffs. Its stem segments easily detach, which enables rapid vegetative dispersal. The species is well established at this location. Tephrocactus articulatus, the most widely grown species of this genus, is very variable and several varieties have been described. The plants found in Tenerife have long, distinctly flattened spines, a feature of T. articulatus var. papyracanthus (Phil.) Backeb. (see for example Kiesling, 1984). Although most recent workers refrain from using any infraspecific names (e.g. Gilmer & Thomas, 1998; Gorelick & Mahr, 2013), this particular variation may merit at least forma status, for which a new combination is established here. The generic limits of Tephrocactus and other opuntoid cacti have long been under debate. Molecular data, however, have shown that its members form a distinct subclade (Nyffeler & Eggli, 2010; Ritz et al., 2012). Trichocereus huascha (F.A.C. Weber) Britton & Rose, Cact. 2: 142f (Figure 24). Echinopsis huascha (F.A.C. Weber) Friedrich & G.D. Rowley, I.O.S. Bull. 3(3): TENERIFE: Granadilla de Abona: Hoyas de Doña María, Las Arenas-El Médano, N, W, 60 m.s.m. to N, W, 54 m.s.m., , , , , E. Ojeda-Land et al. A native of Argentina, this attractive ornamental species was found in a dry riverbed in El Médano in Tenerife, apparently as a relic of an abandoned cultivation experiment. The species looks rather prolific and now also occurs on the surrounding rocky slopes. 74