ARTÍCULO

Senecio alatopetiolatus (Compositae), a new record for the Colombian flora

JOEL CALVO¹ & FABIO ÁVILA^2,3

¹ Conservatoire et Jardin botaniques de Genève, ch. de l’Impératrice 1, C.P. 71, 1292 Chambésy, Switzerland
² Jardín Botánico de Bogotá “José Celestino Mutis”, av. Calle 63, 68-95, CO-111071, Bogotá, D.C., Colombia
³ Herbario Tropical, cra. 19, 39-31, CO-111311, Bogotá, D.C., Colombia

ORCID iD. J. CALVO: https://orcid.org/0000-0003-2340-7666, F. ÁVILA: https://orcid.org/0000-0002-8225-2548

Author for correspondence: J. Calvo (joel.calvo@ville-ge.ch)

Editor: Núria Garcia-Jacas

ABSTRACT
Senecio alatopetiolatus (Compositae), a new record for the Colombian flora.— Senecio alatopetiolatus is recorded for the first time in Colombia. A discussion of its morphological variability and pictures of living plants are provided.
KEY WORDS: Andes; Asteraceae; Colombia; Ecuador; paramo; South America.

RESUMEN
Senecio alatopetiolatus (Compositae), una nueva cita para la flora colombiana.— Senecio alatopetiolatus se cita por primera vez en Colombia. Se incluye una discusión de su variabilidad morfológica y se aportan fotografías de plantas en su hábitat.
PALABRAS CLAVE: Andes; Asteraceae; Colombia; Ecuador; páramo; Sudamérica.

CONTENIDOS

INTRODUCTIONTop

Within the Americas, the second most diverse family is Compositae with ca. 12,043 species. One of the largest genera is Senecio L., which appears to be the most diverse Compositae genus in Bolivia, Peru, and the Southern Cone (Ulloa Ulloa et al., 2017Ulloa Ulloa, C., Acevedo-Rodríguez, P., Beck, S., Belgrano, M. J., Bernal, R., Berry, P. E., Brako, L., Celis, M., Davidse, G., Forzza, R. C., Gradstein, S. R., Hokche, O., León, B., León-Yánez, S., Magill, R. E., Neill, D. A., Nee, M., Raven, P. H., Stimmel, H., Strong, M. T., Villaseñor, J. L., Zarucchi, J. L., Zuloaga, F. O. & Jørgensen, P. M. 2017. An integrated assessment of the vascular plant species of the Americas. Science 358: 1614–1617. https://doi.org/10.1126/science.aao0398).

In Colombia, Senecio is one of the most diverse plant genera at elevations above 3500 m (Bernal, 2016Bernal, R. 2016. La flora de Colombia en cifras. In: Bernal, R., Gradstein, S. R. & Celis, M. (Eds.), Catálogo de plantas y líquenes de Colombia 1. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá: 115–137.). Ávila et al. (2016Ávila, F., Funk, V. A., Diazgranados, M., Díaz-Piedrahita, S. & Vargas, O. 2016. Asteraceae. In: Bernal, R., Gradstein, S. R. & Celis, M. (Eds.), Catálogo de plantas y líquenes de Colombia 1. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá: 795–908.) recorded 43 species in this country. This number, however, increases when the species treated by these authors under Culcitium Bonpl. (2 spp.) and Lasiocephalus Willd. ex Schltdl. (12 spp.) are included; both genera are currently widely accepted as being part of Senecio (Pelser et al., 2007Pelser, P. B., Nordenstam, B., Kadereit, J. W. & Watson, L. E. 2007. An ITS phylogeny of tribe Senecioneae (Asteraceae) and a new delimitation of Senecio L. Taxon 56: 1077–1104. https://doi.org/10.2307/25065905; Sklenář, 2012Sklenář, P. 2012. Senecio josei and S. superparamensis spp. nov. (Asteraceae: Senecioneae) from the Andes of Ecuador. Nordic Journal of Botany 30: 394–398. https://doi.org/10.1111/j.1756-1051.2012.01183.x; Calvo & Freire, 2016Calvo, J. & Freire, E. 2016. A nomenclator of Senecio group Lasiocephalus (Compositae, Senecioneae): nomenclatural and taxonomic notes and new typifications. Phytotaxa 260: 116–130. https://doi.org/10.11646/phytotaxa.260.2.2; Salomón et al., 2018Salomón, L., Sklenář, P. & Freire, S. E. 2018. Synopsis of Senecio series Culcitium (Asteraceae: Senecioneae, Senecioninae) in the Andean region of South America. Phytotaxa 340: 1–47. https://doi.org/10.11646/phytotaxa.340.1.1). In addition, two new species (Calvo & Ávila, 2016Calvo, J. & Ávila, F. 2016. Senecio piedrahitae (Compositae, Senecioneae), a new species from the Colombian Andes. Phytotaxa 283: 91–95. https://doi.org/10.11646/phytotaxa.283.1.7; Aguilar-Cano & Hind, 2020Aguilar-Cano, J. & Hind, D. J. N. 2020. Senecio scapioides (Compositae: Senecioneae: Senecioniinae): a new species from the Departamento de Boyacá, in Andean Colombia. Kew Bulletin 75: 35. https://doi.org/10.1007/S12225-020-9884-4) and a new record (Buira et al., 2018Buira, A., Velasco, C. A. & Calvo, J. 2018. Taxonomic notes, distribution, and conservation status of two species of Asteraceae firstly recorded for Colombia. Anales del Jardín Botánico de Madrid 75: e074. https://doi.org/10.3989/ajbm.2514) were added after Ávila’s account. On this basis, we estimate that Colombia harbors ca. 60 Senecio species.

Although the knowledge of the genus in Colombia has notably been improved during the last decades, especially thanks to the studies by Cuatrecasas (1950Cuatrecasas, J. 1950. Contributions to the flora of South America. Studies on Andean Compositae–I. Studies in South American Plants–II [Fieldiana, Botany 27 (1)]. Chicago Natural History Museum, Chicago. https://doi.org/10.5962/bhl.title.2288, 1951Cuatrecasas, J. 1951. Contributions to the flora of South America. Studies on Andean Compositae–II. Studies in South American Plants–III [Fieldiana, Botany 27 (2)]. Chicago Natural History Museum, Chicago. https://doi.org/10.5962/bhl.title.2414, 1953Cuatrecasas, J. 1953. Neue und bemerkenswerte andine Compositen. Feddes Repertorium Specierum Novarum Regni Vegetabilis 55: 120–153. https://doi.org/10.1002/fedr.19530550203), a solid and comprehensive taxonomy of Senecio is far to be reached. Herein, we record a new species of Senecio for the Colombian flora.

MATERIALS AND METHODSTop

This contribution is the result of bibliographic review, fieldwork in southern Colombia, and the revision of specimens kept at CAUP, COL, HT, JBB, and UDBC; herbarium acronyms follow Thiers (2021Thiers, B. 2021. 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 September 22, 2020, from http://sweetgum.nybg.org/science/ih/).

RESULTS AND DISCUSSIONTop

Senecio alatopetiolatus J. Calvo, E. Freire & Sklenář is recorded for the first time in Colombia (Fig. 1A, B). The species was described in 2016 from Cerro Hermoso in central Ecuador and it was hitherto known only from the type locality (Figs. 1C, D). It is an erect or scandent subshrub up to 2 m long characterized by having triangular to trullate middle cauline leaves with winged petioles broadened towards the base (Fig. 2A), and panduriform to lanceolate upper cauline leaves that become sessile upwards. The synflorescences are cymose-corymbiform composed of discoid, nodding capitula; these have (13–)15–22 involucral bracts, (7–)11–16 supplementary bracts, and 55–75 pale yellow florets (Figs. 2B–E). The immature achenes are glabrous. The stems, leaves, and synflorescences are densely covered by an indumentum composed of glandular-hirsute trichomes mixed with sericeous trichomes (description adjusted from Calvo et al., 2016Calvo, J., Freire, E. & Sklenář, P. 2016. A new species of Senecio (Compositae, Senecioneae) from Ecuador. Phytotaxa 243: 175–179. https://doi.org/10.11646/phytotaxa.243.2.8).

Figure 1. Senecio alatopetiolatus: (A), stem upper part; (B), synflorescence; pr. Cascada del Bedón, Puracé, Cauca, Colombia (photographs: J. Calvo, 2017). (C), stem upper part; (D), synflorescence; Cerro Hermoso, Tungurahua, Ecuador (photographs: P. Sklenář, 2010). [View full size] [Descargar tamaño completo]

Figure 2. Senecio alatopetiolatus: (A), cauline leaf shape variability; (B), capitulum; (C), florets; pr. Cascada del Bedón, Puracé, Cauca, Colombia (photographs: J. Calvo, 2017). (D), capitulum; (E), florets; Cerro Hermoso, Tungurahua, Ecuador (photographs: P. Sklenář, 2010). [View full size] [Descargar tamaño completo]

The Colombian population was found in a shrubby paramo between the San Rafael Lagoon and El Bedón Falls in the Cauca Department (southern Colombia). Plants from this population are slightly smaller (up to 1 m tall) and they have an erect or leaning habit rather than the typically scandent habit of the plants from the type locality. They also differ from those of Ecuador in having the style branch apices ornamented with a crown of trichomes of different lengths instead of with a central tuft of longer trichomes (penicillate). We found no work revealing intraspecific variability of this character in Senecio, however, interspecific variability is well documented (Pelser et al., 2007Pelser, P. B., Nordenstam, B., Kadereit, J. W. & Watson, L. E. 2007. An ITS phylogeny of tribe Senecioneae (Asteraceae) and a new delimitation of Senecio L. Taxon 56: 1077–1104. https://doi.org/10.2307/25065905; Salomón et al., 2016Salomón, L., Hernández, M. P., Giuliano, D. A. & Freire, S. E. 2016. Floral microcharacters in South American species of Senecio s. str. (Asteraceae) with considerations on the circumscription of this genus. Phytotaxa 244: 1–25. https://doi.org/10.11646/phytotaxa.244.1.1). Indeed, Salomón et al. (2016) concluded that this character provides scarce taxonomic information because some species display intermediate states that difficult the characterization of the style branch apices as penicillate or not. Since all other characters perfectly match each other, we resolve that the difference in this character by its own does not support the recognition of more than a single taxon. The aforementioned differences concerning the habit are also unworkable for discriminating purposes and they expand only the variability encompassed by S. alatopetiolatus.

Senecio alatopetiolatus J. Calvo, E. Freire & Sklenář in Phytotaxa 243 (2): 177. 2016.

Ind. loc.: “ECUADOR. Tungurahua: near laguna at the western side of Cerro Hermoso, 1° 13ʹ 51ʺ S, 78° 18ʹ 04ʺ W, 3870 m, 3 Dec 2010, P. Sklenář 13100”.

Holotype: Ecuador, Tungurahua, near laguna at the western side of Cerro Hermoso, 1° 13ʹ 51ʺ S, 78° 18ʹ 04ʺ W, 3870 m, 3-XII-2010, P. Sklenář 13100 (PRC 405860!; isotypes: MO s.n., QCA 215788!).

Distribution and habitat: Colombia (Cauca), Ecuador (Tungurahua). It grows in humid shrubby paramos at elevations of 3100–3870 m. Some species observed in the habitat of the Colombian population are Azorella crenata Pers. (Umbelliferae), Baccharis L. (Compositae), Oreopanax Decne. & Planch. (Araliaceae), Rubus coriaceus Poir. (Rosaceae), Senecio involucratus (Kunth) DC. (Compositae), and Vaccinium floribundum Kunth (Ericaceae).

Additional specimens examined: Colombia, Cauca: Puracé, vía hacia el Parque Nacional Natural Puracé, 3100 m, VIII-2011, Ávila et al. 2005 (UDBC 028149); ibid., 3-I-2017, Ávila 3400 (HT 06810, JBB s.n.); Puracé, alrededores de la cascada del Bedón, 2º 21ʹ 18ʺ N 76º 18ʹ 49ʺ W, 3300 m, páramo arbustivo, 9-XII-2017, Calvo 7678 (CAUP s.n.); Puracé, Parque Nacional Natural Puracé, laguna de San Rafael, 3370 m, 15-II-2000, Ramírez 12818 (CAUP 014678, COL 000101061).

ACKNOWLEDGEMENTSTop

We are very grateful to our colleague Petr Sklenář (Charles University in Prague) for sharing the pictures of S. alatopetiolatus from Ecuador.

REFERENCESTop