Research Article |
Corresponding author: Nicolás Lavandero ( nglavand@uc.cl ) Academic editor: Peter de Lange
© 2020 Nicolás Lavandero, Benito Rosende, María Fernanda Pérez.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Lavandero N, Rosende B, Pérez MF (2020) Leucheria cantillanensis (Nassauvieae, Asteraceae), a new species endemic to Central Chile. PhytoKeys 169: 99-117. https://doi.org/10.3897/phytokeys.169.57532
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A new species, Leucheria cantillanensis sp. nov., endemic to the coastal mountain range of Central Chile, is described. By using both nDNA and cpDNA, phylogenetic relationships of the new species were investigated. This new species belongs to the acaulescent/subacaulescent clade of Leucheria, which is congruent with the morphology of the species. A detailed description, distribution map, insights about its habitat, conservation status, and illustrations are provided. An updated key for acaulescent/subacaulescent species of Leucheria from Central Chile is also given.
Asteraceae, Cantillana, Leucheria, rupicolous flora, taxonomy
The ecosystems found in central and southern Chile are one of 35 world biodiversity hotspots, owing to their combination of great diversity and high levels of endemism, and a past and ongoing loss of habitat and biodiversity (
The genus Leucheria comprises 49 species (
In the context of the ongoing taxonomic revision of the genus, unusual specimens of Leucheria were collected at the Reserva Natural Altos de Cantillana (MMA 2018). The locality is known as one of the 72 priority sites for the conservation of biodiversity in Chile and the top in priority within the Metropolitan Region (
During the austral summer of 2019, a botanical exploration was made to the coastal mountain range of the Metropolitan Region of Chile, specifically to the Reserva Natural Altos de Cantillana (Fig.
The assessment of the conservation status of the species was made using the International Union for Conservation of Nature (
DNA sequences for nDNA (ITS), as well as cpDNA intergenic spacers (rpl32-trnL and trnF-trnL) were obtained from GenBank (www.ncbi.nlm.nih.gov/Genbank) for all species of Leucheria recognized in the phylogenetic reconstruction of the genus (
Total genomic DNA was extracted from silica-dried material collected in the field from the type specimen using the Qiagen DNeasy Plant Mini Kit (QIAGEN, Santiago, Chile) following the manufacturer’s instructions. Genomic DNA was used to amplify by PCR the internal transcribed spacer region (ITS) and the chloroplast trnL-trnF (
The assembled sequences were aligned using the ClustalW algorithm in Geneious Prime 2019.1.1 (https://www.geneious.com). Phylogenetic analyses were carried for both Maximum-likelihood (ML,
The DNA matrix contained 2962 nucleotide characters (782 ITS, 1224 rpl32-trnL and 956 trnL-trnF), representing 44 ingroup and 4 outgroup accessions. BI and ML analyses yielded congruent topologies. The topology of the phylogenetic tree constructed in this study is congruent with the three major clades within the genus found by
Phylogeny of Leucheria resulting from Bayesian analysis of the combined nuclear ITS and plastid rpl32-trnL and trnL-trnF dataset. Numbers above and below the branches represent the Posterior probabilities from the BI analysis and bootstrap values from the ML analysis, respectively. Nodes with <0.5 PP were collapsed to polytomies. The new species, Leucheria cantillanensis is highlighted in bold.
Leucheria cantillanensis is similar to L. salina but differs in its flat lamina and chartaceous texture (vs. foliar segments perpendicular or oblique to the lamina axis and leathery texture) (Figs
Chile. Región Metropolitana: Provincia de Melipilla, entre el límite de Alhué y Melipilla, Reserva Natural Altos de Cantillana, 33°54'54.24"S, 70°58'43.57"W, 2007 m., 27 December 2019, fl. And fr., Lavandero 700 (holotype: CONC!; Isotype SGO!).
Perennial caulescent herb 15–30(–40) cm tall, decumbent, forming clumps of 5–6 aerial stems arising from the apex and nodes of the distal end of the rhizome. Rhizome dark brown, round, 10–15 mm wide, oblique to creeping, leafless below, but with remnants of dry leaf petioles, roots arising from the internodes. Roots dark brown, ca. 2 mm wide, round in cross-section. Stems purplish at the base, green at the top, 1.0–5.5 mm wide, simple or branching, round in cross-section, internodes up to 4 cm long, densely covered by glandular, capitate, (87–)115–180 µm long, multicellular (6–12-celled) trichomes with clear resin, fragrant, with pungent citric scent (same indumentum up to the corolla tube). Leaves dark green, alternate; basal leaves petiolate, semi-densely arranged at the base; petiole compressed, winged, vaginate, 2–2.5(–3.5) cm long; upper leaves sessile, amplexicaul, loosely arranged, gradually reduced in size towards the capitulescences. Lamina obovate, (10-)50–100(–140) × (5–)20–25(–35) mm; base attenuate, amplexicaul, apex mucronate; margin serrate, texture chartaceous, densely glandulous on both surfaces; pinnatisect to entire towards the tip; segments at the base entire, rarely 1(–2)-dentate, apex mucronate; segments in the middle (3–)4–6(–7)-dentate; apical segments fused, doubly dentate; venation conspicuously prominent, with the secondary and tertiary veins forming a raised pattern on both sides of the lamina, pinnate, semicraspedodromous, with primary vein ending in apical mucro, secondary veins either ending in second-order teeth or joining other distal secondary veins. Capitulescences a corymbiform cyme. Capitula 1–6 per stem, pedunculate, (0.5–)1.2–2.8(–3.6) cm long, homogamous, discoid. Involucres hemispheric 7.0–7.2 × 8.2–8.3 mm, two-seriate, alternate. A third series of Middle involucral bracts with intermediate characters between outer and inner Middle involucral bracts rarely present. Receptacle slightly convex, epaleate, glabrous. Outer Middle involucral bracts 5–6, green, lanceolate, concave on the inner face, 6.6–7.6 × 1.10–1.21(–1.36) mm, with 3 dark-green longitudinal stripes (including the midrib), apex ciliate, margin entire, texture leaf-like, abaxial lamina and margins densely covered by glandular trichomes, adaxial lamina glabrous. Middle involucral bracts rarely present, 1–2, green, lanceolate, concave to flat, with 6.5–7.0 × 1.08–1.19 mm, with 3 dark-green longitudinal stripes (including the midrib), apex ciliate, texture leaf-like to hyaline towards the margins, margin ciliate, rarely glandular, central portion of the abaxial lamina covered by glandular trichomes, hyaline lamina glabrous. Inner Middle involucral bracts 5–6(–8), green, lanceolate, concave to flat 6.2–7.1 × 1.06–1.25(–1.51) mm, with 3 dark-green longitudinal stripes (including the midrib), apex acute, texture leaf-like to hyaline-membranaceous towards both lateral margins, margin ciliate, cilia (0.11–)0.17–0.21(–0.24) mm long, central portion of the abaxial lamina densely covered by glandular trichomes, hyaline lamina glabrous, adaxial lamina glabrous. Flowers isomorphic, bisexual, 27–30 per capitulum. Corollas bilabiate, white, before anthesis pinkish-white, tube 3.7–4.0 mm long, 0.5–1.1 wide; corolla tube sparsely covered by glandular trichomes. Outer lip oblanceolate, 3.6–3.9 × 2.0–2.2 mm at its widest, apex 3-toothed, teeth equal, 4-veined, glabrous. Inner lip bifid, lacinae linear, 2.7–2.8 × 0.24–0.37 mm at its widest, connivent, glabrous. Stamens 5, 3.8–4.0 mm long, glabrous. Anthers sagittate, 3.25–3.29 mm long; apical appendages purple, lanceolate, 1.19–1.23 mm long, apex acute; tails long, lanceolate, ca. 0.6 mm long, apex acute, smooth to ciliate. Styles white, 4.2–5.0 mm long, cleft into two truncate branches, branches 0.54–0.73 mm long, with stigmatic papillae on internal surface. Cypselae dark-brown, 1.0–1.2 × 2.4–2.5 mm, obovoid, strigose; trichomes transparent, cylindric, terete, (150–)167–170(–180) µm, ascending, unicellular, subtended by two globose exocarpic cells. Pappus uniseriate, fused at their bases into a ring, deciduous; bristles 19–20, white, capillary, sub-plumose, 4.5–5 mm long; pectines long, filiform, 0.21–0.35(–0.46) mm long, laterally inserted.
Leucheria cantillanensis Lavandero, sp. nov. A habit B capitulum C detail of flower D fruit E basal leaf F leaf trichome G stem trichome H inner Middle involucral bract I middle Middle involucral bract J outer Middle involucral bract K ciliate margin of inner Middle involucral bract (detail). Illustrations by Benito Rosende.
Leucheria cantillanensis seems to be endemic to the Cantillana Mountain Range, which is part of the coastal mountain range of central Chile. It grows in shaded crevices of rocky outcrops near 2000 m a.s.l. with SW orientation (Fig.
Collected flowering and fruiting in December.
The specific epithet refers to the coastal mountain range where the species was found, Altos de Cantillana.
Leaf morphology and habit of acaulescent/subacaulescent Leucheria from Central Chile A Leucheria scrobiculata (NL433, CONC), inset: Habit B Leucheria candidissima (Lavandero, Santilli & Ossa 36, CONC), inset: Habit C Leucheria salina (Lavandero & Abello 40, CONC), inset: Habit D Leucheria cantillanensis (NL700, CONC), inset: Habit. All photographs by Lavandero.
Leucheria cantillanensis is assessed here as Critically Endangered (CR) under the IUCN categories and criteria B2ab(i,ii,iii). Criterion B2 was selected because its Area of Occupancy is <10 km2 (4 km2). Criterion “a” was selected because it is known to exist at only a single location, with only one subpopulation. Criterion b(i,ii,iii) was selected because we expect a continuing decline of suitable area for the species to exist in since it is only found at the highest elevations within the mountain coastal range with very specific soil types and exposition. The quality of its habitat has also been deteriorating over time. The overall precipitation and snow cover in the Cantillana plateau has decreased dramatically over the past 20 years, affecting not only the Andean relict flora but all the vegetation in the area. Fog events which compensate for the drought over the summer, are not as common as before. Leucheria cantillanensis is present in the private reserve “Reserva Natural Altos de Cantillana”.
Leucheria salina (A, D, G, J) (Valle Nevado, Región Metropolitana, Chile), Lecheria runcinata (B, E, H, K) (Reserva Natural Altos de Cantillana, Región Metropolitana, Chile), and Leucheria cantillanensis (C, F, I, L) (Reserva Natural Altos de Cantillana, Región Metropolitana, Chile) A–C habit D–F capitula G–I abaxial side of leaves J–L belowground structures. All Photographs by Lavandero.
Habitat of Leucheria cantillanensis in Central Chile A southwest facing rock outcrops, ca. 2000 m elevation B rock outcrops in Cantillana, general view C general view of rock outcrops among Nothofagus macrocarpa (A.DC.) F.M. Vázquez & R.A. Rodr. forests in the Cantillana plateau D Leucheria cantillanensis, detail of the plant growing between rock crevices. Photographs A, D by Lavandero, B, C by Fabiola Gamboa.
The caulescent herbs with lignified taproots and annual species are excluded. It is important to observe the belowground structures in fresh and dry specimens in order to correctly assign the species to this group. For the habit, please refer to the insets in Figure
1 | Plants densely tomentose, greyish; Corolla pink | L. candidissima |
– | Plants not densely tomentose, glabrous or glandulous; Corolla white to bluish | 2 |
2 | Plants caespitose, up to 8 cm tall, glabrous to glabrescent | L. scrobiculata |
– | Plants erect or decumbent, taller than 8 cm, densely glandulous | 3 |
3 | Lamina with foliar segments perpendicular or oblique to the axis of the lamina, non-prominent venation; flowers 40–60 per capitula, anther apical appendages greenish-yellow; Andes of Chile and Argentina above 3000 m.a.s.l. | L. salina |
– | Lamina flat with foliar segments on the same axis of the lamina, conspicuously prominent venation; flowers 27–30 per capitula; anther apical appendages purple. Coastal Cordillera of Chile near 2000 m.a.s.l. | Leucheria cantillanensis |
The ability to establish infrageneric relationships using classic chloroplast markers and ITS within Leucheria is demonstrated in the present study. We were able to corroborate our initial conjectures about the phylogenetic position of Leucheria cantillanensis within the genus. Based on belowground structures (rhizome and roots), we assumed this species belonged to the acaulescent/subacaulescent group found by
From the biogeographic point of view, it is interesting to note that the closest species of L. cantillanensis are mainly found at high elevations in the Andes range (except for L. suaveolens, which is endemic to the Falkland Islands). Although we do not have a time-calibrated phylogeny for Leucheria, it is possible to hypothesize, based on
Leucheria cantillanensis is an exclusively rupicolous species. Plant communities on rocky places are characterized by having high levels of endemism caused by the high specialization that plants require to thrive in these specific habitats (
The discovery of this new species, which is restricted to mountain tops in the Cantillana Mountain Range in Central Chile, highlights the importance of this site in terms of its unique biodiversity. Cantillana harbours several taxa endemic to the Mediterranean region of Chile (
Leucheria salina. CHILE. Atacama: Huasco, Quebrada Cantarito, 28°39'S, 69°50'W, Feb 1981, Kalin 81614 (CONC); Coquimbo: Limarí, Cordillera de Ovalle, Río Mostazal, 30°46'S, 70°30'W, Feb 1956, Jiles 2971 (CONC); Cordillera de Ovalle, San Miguel, 30°51'S, 70°31'W, Jan 1954, Jiles 3638 (CONC); Gordito, 31°04'S, 70°23'W, Jan 1954, Jiles 2546 (CONC); Valparaíso: Los Andes, entre estero Caracoles y Cristo Redentor, 34°00'S, 70°06'W, Apr 1933, Looser 67007 (CONC), Caracoles, 32°50'S, 70°07'W, Jan 1964, Marticorena & Matthei (CONC); Portillo 32°50'S, 70°08'W, Feb 1951, Ricardi 1207 (CONC); Región Metropolitana: Santiago, Cordillera Santiago ad limit nivis perpet, Feb 1854, Philippi s/n (SGO); SN Yerba Loca, Cuenca Estero La Leonera, 33°16'S, 70°15'W, Feb 2000, Kalin et al. 201451 (CONC); Subida al Portezuelo de El Cepo, 33°18'S, 70°12'W, Mar 1956, Schlegel 1087 (CONC); Farellones, La Parva, 33°19'S, 70°16'W, Jan 1991, Ruthsatz 6995; Farellones, Laguna Piuquenes, 33°19'S, 70°15'W, Feb 2019, Lavandero & Abello 1890 (SGO); Cerca de la Parva, 33°18'S, 70°17'W, Jan 1979, Muñoz & Meza 1372 (SGO); Río Colorado, 33°28'S, 70°00'W, Jan 1930, Behn s/n (CONC); San Ramón, 33°28'S, 70°25'W, Jan 1967, Zoellner 1430 (CONC); El Volcán, 33°48'S, 70°10'W, Feb 1947, Gunckel 20683 (CONC); Maipo, Cajón del Maipo, 33°48'S, 70°44'W, Jan 1980, Niemeyer s/n (CONC); Santiago, Parque Nacional El Morado, 33°49'S, 70°05'W, Jan 1991, Teillier et al. 2402 (CONC, SGO); Cercanías glaciar La Paloma, Feb 2014, Medina 2616 (SGO).
Leucheria runcinata. CHILE. Valparaíso: Nogales, Cordillera El Melón, Estero Garretón 32°39'S, 71°02'W, Nov 2010, Flores-Toro s/n (SANT); Quillota, Cerro La Campana, sector La Gotera, 32°58'S, 71°08'W, Jan 1937, Garaventa 3253 (CONC); Cerro La Campana, 32°57'S, 71°08'W, Nov 1962, Weisser 395 (CONC); Cerro La Campana, Trayecto Placa Darwin a Mina, 32°57'S, 71°08'W, Dec 1981, Villagrán & Meza 3174 (SGO); Quillota, Cerro Vizcachas, 33°05'S, 71°02'W, Nov 1973, Stebbins 8912 (SGO); Región Metropolitana: Chacabuco, Altos de Chicauma, sector Tranque, 33°10'S, 70°58'W, Jan 2003, García & Faúndez 3637 (CONC); Melipilla, Reserva Natural Altos de Cantillana, sendero camino a cerro Horcón de Piedra, 33°53'S, 71°00'W, 27 Dec 2019, Lavandero 753 (SGO).
We are grateful to the curators and staff of CONC and SGO herbaria. We thank Gioconda Peralta and Loreto Carrasco of the Plataforma de Secuenciación y Tecnologías Ómicas, Pontificia Universidad Católica de Chile for laboratory support and expert capillary electrophoresis analysis (CONICYT–FONDEQUIP EQM150077). We would like to thank Prof. Sergei Mosyakin and one anonymous reviewer for the helpful comments on the submitted manuscript. Thanks to Fabiola Gamboa for providing photos of Altos de Cantillana. We are indebted to Martin Gardner (RBGE), who carefully revised the manuscript. We would like to thank Sebastian Teillier for his helpful comments on the manuscript and his keen interest in the flora of the Metropolitan Region. We would like to thank the logistic support from “Proyecto GEF 5135” MMA and ONU Medio Ambiente, that invited us to participate in their floristic survey in their permanent plots of flora in Altos de Cantillana, part of the SIMBIO RMS. Herbarium and lab work were funded by the Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) from the Government of Chile (Fondecyt grant 1171369). Special thanks to Corporación Altos de Cantillana for the logistic support in the field and all the hard work they do to keep this Natural Reserve preserved.
Table S1. GenBank accession numbers used in this study
Data type: molecular data
Explanation note: GenBank accession numbers for the ITS, trnL-trnF and rpl32-trnF sequences used in this study. GenBank accessions in bold are new to this study.