ARTÍCULO

On the identity and status of Desmanthus (Leguminosae, Mimosoid clade) in Macaronesia

F. VERLOOVE¹ & L. M. BORGES²

¹ Botanic Garden of Meise, Nieuwelaan, 38, B-1860 Meise, Belgium

² Departamento de Botânica, Universidade Federal de São Carlos, Rodovia Washington Luís, km 235, BR-13565-905 São Carlos, SP, Brazil

ORCID iD. F. VERLOOVE: http://orcid.org/0000-0003-4144-2422, L. M. BORGES: http://orcid.org/0000-0001-9269-7316

Author for correspondence: F. Verloove (filip.verloove@botanicgardenmeise.be)

Editor: T. Garnatje

On the identity and status of Desmanthus (Leguminosae, Mimosoid clade) in Macaronesia

ABSTRACT
On the identity and status of Desmanthus (Leguminosae, Mimosoid clade) in Macaronesia.— In this paper, the identity and degree of naturalization of Desmanthus (Leguminosae, Mimosoid clade) in the Canary Islands (Gran Canaria, Fuerteventura) and Cape Verde (Santo Antão, São Vicente) are critically re-assessed. The study of morphological features of the plant material sampled allowed to conclude that all specimens must be assigned to D. pernambucanus, instead of D. virgatus as previously thought. Previous records for D. virgatus from Macaronesia still require confirmation but are probably all erroneous. D. pernambucanus is well-established and the number of populations is increasing in the studied area. The species can be classified as an environmental weed or even as a transformer species in natural habitats, often barrancos. The results also show that the distinction between D. pernambucanus and D. virgatus is not always clear-cut and that for an accurate identification the study of living material usually is required.
KEY WORDS: Desmanthus pernambucanus; Desmanthus virgatus; Fabaceae; identification; invasive species.

Sobre la identidad y el estatus de Desmanthus (Leguminosae, clado Mimosoideae) en Macaronesia

RESUMEN
Sobre la identidad y el estatus de Desmanthus (Leguminosae, clado Mimosoideae) en Macaronesia.— En este artículo se reevalúa la identidad y grado de naturalización del género Desmanthus (Leguminosae, clado Mimosoideae) en diversas áreas de las Islas Canarias (Gran Canaria, Fuerteventura) y de Cabo Verde (Santo Antão, São Vicente). El estudio de los caracteres morfológicos del material vegetal permitió concluir que todos los especímenes deben ser asignados a D. pernambucanus, en lugar de a D. virgatus, como se pensaba hasta ahora. Los registros previos de D. virgatus para Macaronesia requieren confirmación, pero posiblemente sean todos erróneos. Desmanthus pernambucanus está bien establecido en la zona estudiada y el número de poblaciones se está incrementando. La especie puede ser clasificada como “mala hierba alóctona” o, incluso, como una especie transformadora en hábitats naturales, especialmente en barrancos. Los resultados también muestran que no siempre está clara la distinción entre D. pernambucanus y D. virgatus y que, generalmente, el estudio de material vivo es necesario para una identificación precisa.
PALABRAS CLAVE: Desmanthus pernambucanus; Desmanthus virgatus; especies invasoras; Fabaceae; identificación.

CONTENIDOS

INTRODUCTIONTop

Desmanthus Willd. (bundleflower) is, in its current circumscription, an exclusively New World genus with 24 representatives (Luckow, 1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ). The center of diversity of the genus seems to be in Mexico where 14 species occur, seven of which are endemic. Several species are grown as cover crops, fodder or pasture species (e.g. Gardiner et al., 2013Gardiner, C., Kempe, N., Hannah, I. & McDonald, J. 2013. PROGARDES: a legume for tropical/subtropical semi-arid clay. Tropical Grasslands 1: 78−80. https://doi.org/10.17138/TGFT(1)78-80. ) and at least one, Desmanthus pernambucanus (L.) Thell., has become a pantropical weed (Mabberley, 2008Mabberley, D. J. 2008. Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge.). This species naturally occurs in the Caribbean (most islands, including Bermuda, Bahamas, Cuba, Hispaniola, Puerto Rico, Virgin Islands, Guadeloupe, Anguilla, St. Kitts, Montserrat, Antigua, Martinique, Barbados, Grenada, Tobago and Trinidad) and is also known from South America (Guyana, Surinam, and in coastal areas in northeastern Brazil). It is widely introduced and naturalized elsewhere, including on islands in the Pacific and Indian Ocean, in South Africa, southeastern Asia and southeastern USA (Florida) (Luckow, 1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ). In its area of origin, D. pernambucanus is usually found along moist roadsides and ditches, in abandoned pastures, coastal thickets and at the edges of marshes (Luckow, 1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ). A very similar species, Desmanthus virgatus (L.) Willd., has an even wider natural distribution and ranges from Texas and Florida in the USA., across eastern and southern Mexico, Central America and the Caribbean to South America. It grows in often heavily disturbed habitats such as railroad tracks, pastures, roadsides, coastal thickets and on beaches (Luckow, 1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ).

The taxonomy of the genus is particularly challenging and this is most notable in the D. virgatus complex. In her monograph of Desmanthus, Luckow (1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ) resolved many taxonomic problems in the genus. The detailed cladistic and morphometric analyses shed new light on species relationships. For instance, it became clear that D. virgatus, the species with the most extensive native distribution in the complex, has widely been confused with D. pernambucanus. Claims of it from the Old World (sub-) tropics turned out to be mostly referable to the latter. Since the publication of Luckow’s monograph, several regional data recording D. virgatus as a weed have been corrected, e.g. in Hawaii (Wagner & Herbst, 1995Wagner, W. L. & Herbst, D. R. 1995. Contributions to the flora of Hawai‘i. IV. New records and name changes. Bishop Museum Occasional Papers 42: 13–27.), Australia and South Africa (Cook et al., 2005Cook, B. G., Pengelly, B. C., Brown, S. D. et al. 2005. Tropical forages. CSIRO, DPI&F (Qld.), CIAT & ILRI, Brisbane.) and China (Wu & Nielsen, 2010Wu, D. L. & Nielsen, I. C. 2010. Mimoseae. In: Wu, Z. Y., Raven, P. H. & Hong, D. Y. (Eds.), Flora of China 10. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis: 50–54.).

Linnaeus (1753Linnaeus, C. 1753. Species plantarum 1. Laurentii Salvii, Stockholm.) distinguished both (as Mimosa pernambucana L. and Mimosa virgata L. respectively) based on stamen number: flowers pentandrous in D. pernambucanus, while decandrous in D. virgatus. However, this is a variable character and both species can have either ten (usually) or five (rarely) stamens (Luckow, 1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ). Moreover, both were shown to be only remotely related (Luckow, 1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ). Species of the D. virgatus group [Desmanthus glandulosus (B. L. Turner) Luckow, Desmanthus pubescens B. L. Turner and D. virgatus] were characterized by upward nyctinastic pinnae movements while pinnae move downward in D. pernambucanus. The latter belongs to the Desmanthus acuminatus group, along with D. acuminatus Benth., Desmanthus paspalaceus (Lindman) Burkart—probably its closest relative—and Desmanthus tatuyhensis Hoehne. A synapomorphic trait of this group is seen in the fruits in which sutural ridges roll back longitudinally over the valves; after dehiscence the valves are thus slightly concave. Molecular data presented by Pengelly & Liu (2001Pengelly, B. & Liu, C. 2001. Genetic relationships and variation in the tropical mimosoid legume Desmanthus assessed by random amplified polymorphic DNA. Genetic Resources and Crop Evolution 48: 93−101. https://doi.org/10.1023/A:1011234913710. ) are congruent with the findings of Luckow (1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ). Out of 284 accessions representing 11 species, D. pernambucanus was the only species with representatives from regions other than the Americas, suggesting that this species has the capacity to colonize new regions. They concluded that many of the reports of D. virgatus in extensive regions of the tropics may be D. pernambucanus.

In parts of Macaronesia, a collection of four archipelagos in the North Atlantic Ocean off the coast of the continents of Europe and Africa, a species of Desmanthus was formerly introduced for forage and subsequently became naturalized. It has usually been referred to as D. virgatus (e.g. Hansen & Sunding, 1993Hansen, A & Sunding, P. 1993. Flora of Macaronesia. Checklist of vascular plants (4th revised edition). Sommerfeltia 17: 1−295.; Vidigal, 1996Vidigal, M. P. 1996. Mimosaceae. In: Paiva, J. (Ed.), Flora de Cabo Verde. Plantas vasculares 43. Praia, Lisboa.). However, one of the earliest introductions from the Americas in the Jardín de Aclimatación de la Orotava in Tenerife, Canary Islands, was named as “Mimosa pernambucana”, the basionym of Desmanthus pernambucanus (A. Reyes-Betancort, pers. comm., January 2017). Although Desmanthus was already considered an annoying weed in plant nurseries in Gran Canaria in the 1970’s (e.g. in Tafira and Santa Lucía, see Kunkel, 1972aKunkel, G. 1972a. Novedades en la Flora Canaria: VI. Adiciones y nuevas descripciones. Cuadernos de Botánica Canaria 26: 39−45.; sub D. virgatus) it long remained localized and restricted to anthropogenic habitats, mostly as a garden weed. In the Canary Islands it was also reported from Fuerteventura (Kunkel, 1972bKunkel, G. 1972b. Nuevas adiciones florísticas para las Islas Orientales. Cuadernos de Botánica Canaria 26: 27−38., 1977Kunkel, G. 1977. Las plantas vasculares de Fuerteventura (Islas Canarias), con especial interés de la forrajeras (Naturalia Hispanica, 8). ICONA, Madrid. ; Scholz et al., 2013Scholz, S., Reyes-Betancort, J. A. & Wildpret de la Torre, W. 2013. Adiciones a la flora vascular de Fuerteventura (Islas Canarias). III. Botánica Macaronésica 28: 99−116.). It was not included in a list of naturalized and potentially invasive species in the Canary Islands (Sanz-Elorza et al., 2005Sanz-Elorza, M., Dana, E. D. & Sobrino, E. 2005. Aproximación al listado de plantas vasculares alóctonas invasoras reales y potenciales en las islas Canarias. Lazaroa 26: 55−66. https://doi.org/10.5209/LAZAROA.10201.), while Hohenester & Welss (1993Hohenester, A. & Welss, W. 1993. Exkursionsflora für die Kanarischen Inseln. Verlag Eugen Ulmer, Stuttgart.) accepted it as an escape of cultivation. In this paper the distinguishing features of both species are critically discussed. In addition, the current status of Desmanthus in Macaronesia is re-assessed.

MATERIALS AND METHODSTop

Numerous herbarium specimens of Desmanthus pernambucanus and D. virgatus were examined from the following herbaria: BR, LG, LPA, ORT, SPF and SPSC (herbarium acronyms according to Thiers, 2017Thiers, B. 2017. Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. The New York Botanical Garden, New York. Retrieved August, 2017, from http://sweetgum.nybg.org/science/ih/). These included specimens collected in the study area as well as from various other regions of the world, several of them cited by Luckow (1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ) in her monographic study of the genus.

Field work was conducted by the first author in Gran Canaria in 2011, 2012, 2015 and 2017. In order to accurately assess seedling type and nyctinastic leaf movements, seeds obtained in the field in Gran Canaria were grown in the laboratory.

RESULTS AND DISCUSSIONTop

According to Luckow (1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ), Desmanthus pernambucanus differs from D. virgatus in several respects. However, as shown in Table 1, most of the distinguishing features that can be observed in herbarium specimens, such as stipules indumentum or number of pinnae pairs per leaf, overlap or do not clearly separate the two species. Also, leaflet base shape usually can be used to set D. pernambucanus and D. virgatus apart, but particularly in specimens of D. pernambucanus, square-oblique and rounded-oblique bases are sometimes seen on the same individual [e.g. Brace 4325 (SPSC), from Bahamas]. Habit also appears to be variable in both species (Table 1). Among features that are observable on pressed specimens, the particular morphology of fruiting valves during dehiscence (valves slightly concave vs. rather convex; Table 1) remains as a marked difference between D. pernambucanus and D. virgatus.

All individuals seen from the Atlantic islands are homomorphic: plants are relatively robust with usually erect stems up to 2 m tall; stipules are nearly always markedly pubescent; extra-floral nectaries are very conspicuous, the largest wider than the petiole on which they sit; petioles of mature leaves are distinct, the longest up to 20+ mm long, leaflets have square-oblique bases and fruiting valves tend to become concave at maturity. In addition, based on plants grown from seed collected in the Canary Islands (Gran Canaria) some other important traits were observed: the hypocotyl elongates markedly in seedlings and at night pinnae move downward while petioles remain stationary. All these features, except for leaflet base shape, are characteristic of D. pernambucanus. Seedling morphology and nyctinastic leaf movement patterns were decisive in excluding D. virgatus as occurring in Macaronesia.

Desmanthus pernambucanus (L.) Thell., Fl. Adv. Montpellier: 296 (1912) (Fig. 1, Fig. 2, Fig. 3, Table 1).

≡ Mimosa pernambucana L., Sp. Pl.: 1: 519 (1753Linnaeus, C. 1753. Species plantarum 1. Laurentii Salvii, Stockholm.).

Figure 1. General habit of Desmanthus pernambucanus. Stems are erect and foliage green, not glaucous (Maspalomas, April 2017; photograph: F. Verloove). [View full size] [Descargar tamaño completo]

Figure 2. Detail of flowers of Desmanthus pernambucanus (Maspalomas, April 2017; photograph: F. Verloove). [View full size] [Descargar tamaño completo]

Figure 3. Legumes of Desmanthus pernambucanus in a vegetation with Cyperus involucratus and other invasive species (Arguineguín, November 2011; photograph: F. Verloove). [View full size] [Descargar tamaño completo]

Description (mostly based on specimens seen from Macaronesia): A subshrub, 0.5–1(2) m tall. Stems slender, erect or decumbent, few branched, glabrous or more often slightly hairy, somewhat angular (especially when young). Leaves greenish (not glaucous), alternate, bipinnate, with 2–4(6) pairs of pinnae, each pinna 1–2.5(5) cm long, with 6–21 pairs of leaflets; leaflets linear-oblong to obovate, 4–7 × 0.7–1.6(2) mm, apex abruptly acute, base truncate (square oblique), asymmetric; stipules 3–7 mm long, puberulent, linear; petiole (3.6)4.8–16(20+) mm long, glabrous or hairy, with a nectar gland between the lowest pair of pinnae, this round or elliptic cup-shaped, 1–2.6 mm across. Inflorescence a fascicle of axillary, pedunculate heads, each ca. 7–10 mm across, peduncule 1–4.5 cm long; each head with (4)8–13(30) florets; bracteoles ovate, 1–2 mm long; florets sessile, white-green; calyx tubular, with 5 lobes, 2–2.5 mm long; petals 5, free, ovate, apex acute, 3–4 mm long; stamens 10 (rarely 5), free, white, filaments 5 mm long, anthers 1 mm long; ovary linear-oblong, about 2 mm long; style 2.5–3 mm long; stigma truncate. Fruit a dehiscent, linear, flat, erect to very slightly curved, red-brown pod, 4–8.5(11) × 0.3–0.4 cm, the margins thickened with sutural ridges curling back over the valves (valves slightly concave at maturity), the apex beaked. Seeds ca. 10–20+ per pod, rhomboid, 2.4–3.2 mm long, reddish brown to nearly black, striate (a very detailed description is provided by Luckow, 1993Luckow, M. 1993. Monograph of Desmanthus (Leguminosae: Mimosoideae) (Systematic Botany Monographs, 38), American Society of Plant Taxonomists, Ann Arbor. https://doi.org/10.2307/25027822. ).

Distribution (see also Appendix): In the Canary Islands collections were seen from Gran Canaria and Fuerteventura. In the Cape Verde Islands its presence is here confirmed from Santo Antão and São Vicente. Claims of Desmanthus virgatus from São Nicolau, Boavista, Maio, Santiago and Brava (Vidigal, 1996Vidigal, M. P. 1996. Mimosaceae. In: Paiva, J. (Ed.), Flora de Cabo Verde. Plantas vasculares 43. Praia, Lisboa.; Diniz et al., 2002Diniz, M. A., Duarte, M. C., Martins, E. S., Matos, G. C. & Moreira, I. 2002. Flora das culturas agrícolas de Cabo Verde. Instituto de Investigação Científica Tropical, Lisboa.) require confirmation; all are probably also referable to D. pernambucanus. A picture of a seedling in Diniz et al. (2002Diniz, M. A., Duarte, M. C., Martins, E. S., Matos, G. C. & Moreira, I. 2002. Flora das culturas agrícolas de Cabo Verde. Instituto de Investigação Científica Tropical, Lisboa.) shows an elongated hypocotyl and clearly refers to D. pernambucanus, not to D. virgatus. It is worth mentioning that, also in the Macaronesian Region, there are two recent citations of “Desmanthus virgatus” from Madeira in the GBIF database (https://www.gbif.org/occurrence/921427717, https://www.gbif.org/occurrence/921468911). These claims should be critically re-assessed. Desmanthus was not yet reported from Madeira in recent floras and checklists (Press et al., 1994Press, J. R., Short, M. J. & Turland, N. J. 1994. Flora of Madeira. Natural History Museum, London.; Silva Vieira, 2002Silva Vieira da, R. M. 2002. Flora da Madeira: Plantas vasculares naturalizadas no arquipélago da Madeira. Museu Municipal do Funchal, Funchal.; Borges et al., 2008Borges, P. A. V., Abreu, C., Aguiar, A. M. F. et al. (Eds.). 2008. Listagem dos fungos, flora e fauna terrestres dos Arquipélagos da Maderia e Selvagens. Direcção Regional do Ambiente da Madeira and Universidade dos Açores, Funchal & Angra do Heroísmo.) and probably is a recent introduction there.

Habitat (Fig. 4): In the Canary Islands it is found in anthropogenic (roadsides, gardens, etc.) as well as natural (seasonally dry, gravelly river beds) habitats. In the Cape Verde Islands it is mostly recorded on stony slopes and as a weed in agricultural fields and pastures (Vidigal, 1996Vidigal, M. P. 1996. Mimosaceae. In: Paiva, J. (Ed.), Flora de Cabo Verde. Plantas vasculares 43. Praia, Lisboa.).

Figure 4. Habitat invaded by Desmanthus pernambucanus in Gran Canaria (Arguineguín, November 2011; photograph: F. Verloove). [View full size] [Descargar tamaño completo]

Status in Macaronesia: In recent years Desmanthus pernambucanus was found in Gran Canaria on many occasions and in several different parts of the island, in the arid south as well as in the more humid northern regions. It is particularly common in the seasonally dry, gravelly river bed of the barranco de Arguineguín, at least between Arguineguín and Los Peñones, a stretch of about 12 kilometers in a relatively remote, little disturbed area. It forms dense, often nearly monospecific stands or is accompanied by invasive aliens such as Acacia farnesiana (L.) Willd., Cyperus involucratus Rottb., Dysphania anthelmintica (L.) Mosyakin & Clemants or Pennisetum setaceum (Forssk.) Chiov. Other aliens found in close proximity are: Ageratina adenophora (Spreng.) R. M. King & H. Rob., Argemone ochroleuca Sweet, Cladium jamaicense Crantz, Datura inoxia Mill. and Symphyotrichum squamatum (Spreng.) G. L. Nesom. At least in this area and in the sense of Richardson et al. (2000Richardson, D. M., Pyšek, P., Rejmánek, M., Barbour, M. G., Panetta, F. D. & West, C. J. 2000. Naturalization and invasion of alien plants: concepts and definitions. Diversity and Distributions 6: 93−107. https://doi.org/10.1046/j.1472-4642.2000.00083.x.), Desmanthus pernambucanus can be classified as an environmental weed or even as a transformer species (a taxon that has clear ecosystem impacts, for instance as an excessive user of resources such as water and light). Similar stands, but on a more local scale, have been observed in other barrancos in southern Gran Canaria, for instance in Barranco del Negro near Maspalomas. A future expansion into other suitable habitats is predicted. In Fuerteventura, its presence in the Jandía area has been confirmed recently, although until now it seems to be restricted to disturbed habitats.

In the Cape Verde Islands the oldest collections cited by Vidigal (1996Vidigal, M. P. 1996. Mimosaceae. In: Paiva, J. (Ed.), Flora de Cabo Verde. Plantas vasculares 43. Praia, Lisboa.) date from the 1950’s but it was certainly introduced long before that. At the time of Schmidt (1852Schmidt, J. A. 1852. Beiträge zur Flora der Kapverdischen Inseln. Heidelberg.) it was probably already cultivated for forage, but Coutinho (1914Coutinho, A. X. P. 1914. Herbarii gorgonei universitatis olisiponensis catalogus. Arquivos Universidade da Lisboa 1: 265−334.) reported its first occurrence in the wild. Two decades later Chevalier (1935Chevalier, A. 1935. Les Iles du Cap Vert. Géographie, biogéographie, agriculture. Flore de l’Archipel. Revue de Botanique Appliquée et d’Agriculture Coloniale 15: 733−1090. https://doi.org/10.3406/jatba.1935.5553) reported it as already present on several different islands and, today, it is a naturalized invasive species in pastures and on rocky slopes (Vidigal, 1996Vidigal, M. P. 1996. Mimosaceae. In: Paiva, J. (Ed.), Flora de Cabo Verde. Plantas vasculares 43. Praia, Lisboa.). Moreover, it is a noxious weed in agricultural fields, for instance in crops of maize (e.g. Jansen, 1993Jansen, A.-E. 1993. Erhebungen zur segetalflora des regen- und bewässerungsfeldbaus der Insel Santiago, Kapverden. Courier Forschungsinstitut Senckenberg Series 159: 15−23. ; Diniz et al., 2002Diniz, M. A., Duarte, M. C., Martins, E. S., Matos, G. C. & Moreira, I. 2002. Flora das culturas agrícolas de Cabo Verde. Instituto de Investigação Científica Tropical, Lisboa.).

ACKNOWLEDGEMENTSTop

Field work in Gran Canaria by the first author in March and April 2017 was granted by COST Action - Alien Challenge TD 1209. Dr. A. Reyes-Betancort (Jardín de Aclimatación de La Orotava, Tenerife) is thanked for his assistance in the herbarium (ORT) and for providing useful information on the genus Desmanthus in the Canary Islands. Dr. A. Marrero Rodríguez (Jardín Botánico Viera y Clavijo, Gran Canaria) is acknowledged for sending on loan relevant herbarium specimens from LPA. Finally, two anonymous reviewers substantially improved an earlier version of this paper and Dr. E. Dana (Sevilla, Spain) helped with the preparation of the Spanish abstract.

APPENDIX. Specimens examined from the study area.Top

Desmanthus pernambucanus (L.) Thell.: Cabo Verde, Santo Antão: Ribeira de Torre, cumbres de Ribeirinha Curta, Delgadin – bordes del Pedregal, 750−800 m.s.m., 25°05′00′′ O − 17°08′50′′ N, riscos y bordes de carretera, 11.07.2004, A. Marrero and R. Almeida (LPA 8004); Caibros, chemin, alt. 250 m, 04.03.2007, J. Bouharmont 35501 (BR). São Vicente, Monte Verde (massif culminant de l’île), bord de chemin, en bordure d’un groupement frutescent sur lave, près du sommet, alt. env. 720 m, 20.08.2008, J. Lambinon 08/CV/21 (BR, LG). Spain, Canary Islands: Fuerteventura, El Matorral (Jandía), borde de paseo maritimo, 21.08.2008, S. Scholz (ORT 40540); Pájara, Saladar de Jandía, 3 m, 25.04.2014, C. Samarín and E. Ojeda-Land (ORT 46203). Gran Canaria, Las Palmas de Gran Canaria, confluencia Barranquillo Don Zoilo con Paseo del Chil, UTM 28R DS 578 104, 30 m.s.m., espontáneo en parterres, 03.07.2009, A. Marrero (LPA 26637, LPA 26639); Las Palmas de Gran Canaria, laderas del Parque Doramas a Altavista, UTM 28R DS 577 105, 65 m.s.m., espontáneo en laderas ajardinadas, 03.07.2009, A. Marrero (LPA 26641, LPA 26642); San Agustín, Playa del Águila, plantation weed, 06.11.2011, F. Verloove 9971 (BR); San Agustín, dry talus slope, common, 06.11.2011, F. Verloove 9972 (BR); Arguineguín, barranco de Arguineguín, GC500 +/- km 5−6, dry gravelly riverbed, very invasive weed, 10.11.2011, F. Verloove 9969 (BR); Arguineguín towards Soria, barranco de Arguineguín, GC500 km 4-8, dry gravelly riverbed, very invasive, 12.11.2012, F. Verloove 9910 (BR, LPA 30177, LG); Las Palmas de Gran Canaria, Vega de San José, plantation weed, 15.11.2015, F. Verloove 12070 (SPSC); Pedrazo, barranco del Negro, dry river bed, invasive weed, 17.11.2015, F. Verloove 12095 (SPSC); Maspalomas, Av. Touroperator Tjaereborg, dry rough ground, common, 30.03.2017, F. Verloove 12793 (BR); Maspalomas, right bank of barranco de Fataga N of Av. Alejandro del Castillo, river bank, ruderal, common, 2.04.2017, F. Verloove 12801 (BR); Pasito Blanco, close to the entrance of camping, roadside, ca. 20 fruiting individuals and many seedlings, 03.04.2017, F. Verloove 12807 (BR).

REFERENCESTop