Mikania betancurii J. Aguilar-Cano & S. Díaz, 2015
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publication ID |
https://doi.org/ 10.11646/phytotaxa.208.3.5 |
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persistent identifier |
https://treatment.plazi.org/id/127A87DA-FF93-FFA2-FF3E-F932FD3CFC15 |
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treatment provided by |
Felipe |
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scientific name |
Mikania betancurii J. Aguilar-Cano & S. Díaz |
| status |
sp. nov. |
Mikania betancurii J. Aguilar-Cano & S. Díaz View in CoL , sp. nov.
Type: — COLOMBIA. Antioquia, municipio de Urrao, vereda El Chuscal “on trail to finca La Quince, above Urrao, 6°30´N, 76°10´W, 2500–2800 m, 21 November 1988, G. McPherson, F. J. Roldán & J. Betancur 13239 (holotype COL!, isotypes HUA!, MO).
Diagnosis: — Mikania betancurii is superficially similar to M. flabellata Rusby ex Robinson (1920: 14) and M. lloensis Hieronymus ex Sodiro (1901: 18) as they all have corymbiform synflorescences with strongly elongate peduncles and larger heads. The new species resembles M. flabellata in the overall shape and size of the heads and in the pappus with capillary bristles in 2 or more series; however, M. betancurii possesses hypocrateriform corollas, subcordate leaf blades, which are densely papillose below, and larger (13.8–15 × 3–3.4 mm) phyllaries (vs. narrowly infundibuliform corollas, leaves puberulent to glabrescent below, with rounded bases, and phyllaries 8–11 × 2 mm in M. flabellata ). The habit and the leaf and corolla shape of the new species resemble those found in M. lloensis ; however, the new species has larger heads, up to 17 mm high (vs. heads 12–14 mm high), reddish corolla lobes with a conspicuous midvein (vs. white lobes with conspicuous submarginal veins in M. lloensis ), filaments inserted at the mid-level region of the corolla tube (vs. stamens inserted at the apex of the corolla tube in M. lloensis ), and the retuse apical appendages of the anthers (vs. acute apical appendages; Fig. 2 C–D View FIGURE 2 ).
Description: —Vines with yellowish stems; internodes up to 13 cm long, fistulose, terete, striate to sulcate, scarcely pilose, nodes with a transverse ridge, densely puberulous, hairs multicellular, uniseriate, up to 0.6 mm long. Leaves opposite, petiolate; petioles 1.7–2.5 cm long, slender, swollen at the base; blades membranaceous, ovatetriangular, 5.6–9.9 × 3–3.5 cm, with three or five main veins, base subcordate, apex acuminate to long-acuminate, margins revolute, crenate to undulate, remotely dentate towards the proximal portion, above scabridulous, with scattered multicelular uniseriate strigose hairs, 0.2–0.3 mm long, below densely covered with papillae 0.1–1.15 mm long, each papilla brown at the base and white at the apex. Synflorescences terminal and lateral, 17.5–35 × 4.5–8.5 cm, corymbiform, with first order branches 1–1.4 cm long, opposite to subopposite; peduncle 13–25 cm long, sulcate, puberulous, hairs multicellular, uniseriate, up to 0.6 mm long. Heads grouped in clusters of 3 (triads), each head up to 17 × 5 mm, pedicellate and with a bract at the base of the triad (hereafter called the central bract); lateral heads subtended by a subinvolucral bract 1–1.5 mm below the base of the head and to 90° with respect to the central bract, elliptic-lanceolate to spathulate, up to 9 × 2 mm, base attenuate to pseudopetiolate, less than the length of the involucres, apex acute, with three main veins, membranaceous, glabrous; involucral bracts four, decussate, lanceolate, the outer bracts slightly larger (14.4–15 × 3.2–3.4 mm) than the inner bracts (13.8–14.2 × 3–3.2), dull red, glabrous, striate, apex acute and shortly ciliate. Flowers with corollas whitish, dull red on lobes, glabrous, hypocrateriform, 10.4–11 mm long, tube up to 7.4 mm long, with groups of 8–10 multicelular, moniliform, uniseriate trichomes on the outside of the commisures between the corolla lobes, throat reduced, lobes linear-lanceolate, 2.9–3 × 0.9–1 mm, with a medial vein, apex papillate inside; anthers 2.5–2.8 mm long, totally exserted at maturity, base shortly emarginate, apical appendage oblong-ovate, retuse, up to 0.4 × 0.3 mm, anther collar 0.4–0.5 × 0.2–0.3 mm, filament 4.2–5.6 mm long, inserted in the middle level of the corolla tube; pistil 18 mm long; style to 5.6 mm long, smooth and glabrous at the base, nectary up to 0.6 × 1 mm; stigmatic branches up to 11 mm long, broadening to the apex, appendage 2 mm long, densely covered with short papillae. Achenes 8–10 ribbed, dull brown, 6–6.2 mm long, glabrous; pappus of ca. 112–128 slender capillary bristles in 2 series, gradually narrowed toward tips, 8–9.4 mm long.
Distribution: — Mikania betancurii has only been collected in its type locality north of Frontino municipality, in the department of Antioquia, on the Western Colombian Cordillera, at elevations between 2500 and 2800 m ( Fig. 3 View FIGURE 3 ). It appears that the coordinates on the label of the type specimen are inaccurate, as the exact location has the following coordinates: 6°27.55’N – 76°4.59’W (J. Betancur, personal communication).
Habitat: — Mikania betancurii occurs in a very narrow belt of cloud forests dominated by Quercus humboldtii Bonpland in Humboldt & Bonpland (1809: 155–156), at elevations of 2500–2800 m, near the páramo of Frontino. This páramo is likely an area of endemism, as several species of plants (cf. Idárraga & Callejas 2011) and animals are restricted to it. Examples of plant species are Hyospathe frontinensis Henderson (2004: 963) ( Arecaceae ), Microchilus frontinoensis Ormerod (2008: 75–75) ( Orchidaceae ), Clibadium frontinoense Díaz & Arriagada (1992: 301) , Diplostephium frontinense Cuatrecasas (1991: 123) and Espeletia praefrontina Cuatrecasas (1980: 10–12) of Asteraceae , and Miconia frontinoana Cogniaux & Gleason (1932: 117) ( Melastomataceae ). Animal taxa restricted to the páramo of Frontino are the frogs Pristimantis lasalleorum ( Lynch 1995) and P. satagius ( Lynch 1995) and the reptile Bolitoglossa hypacra ( Brame & Wake 1962).
Comments: —The length of the heads in the new species ( Figs 1D View FIGURE 1 , 2B View FIGURE 2 ) matches that in Mikania chimborazensis Hieronymus ex Sodiro (1901: 15–16) , a species known from northern Ecuador to northern Peru ( Holmes & McDaniel 1982; Robinson & Holmes 2008). These two species possess the longest heads of the genus. A close examination of the type specimen and the original description of M. chimborazensis (Sodiro 767; B (fragments) and F (photograph) shows that the heads of this species are shorter than those described in the monographs of Mikania of Ecuador and Peru ( Holmes & McDaniel 1982, Robinson & Holmes 2008). In addition, the conspicuous midvein on the corolla lobes of the new species ( Fig. 1E View FIGURE 1 ) occurs only in M. ollgaardii Robinson & Holmes (2002: 891–894) . Additional diagnostic characters that distinguish M. betancurii from M. flabellata and M. lloensis include the groups of 8 to 10 multicellular, moniliform, uniseriate trichomes below the commisures on the outside of the corolla tube ( Fig. 1H View FIGURE 1 ), and the retuse apical appendages of the anthers ( Fig. 2C View FIGURE 2 ). Flowers in both, M. flabellata and M. lloensis lack multicellular hairs on the outside of the commisures of the corolla lobes, and the apex of the anther appendages is obtuse or acute ( Fig. 2D View FIGURE 2 ; Robinson & Holmes, 2008).
Pruski & Funston (2011) cited the type specimen of Mikania betancurii (McPherson 13239) as the voucher specimen of M. lloensis (from Colombia and Ecuador) in the Catalogue of the Vascular Plants of the Department of Antioquia ( Colombia). For this paper we examined specimens of the latter species collected in Cundinamarca (Pérez- Arbeláez 6618, COL), Cauca (Ramírez 10174, 9707, PSO) and Antioquia (Roldán 2541, 2542, 3977, HUA). These two species differ in that the new species has longer (up to 17 mm long) heads (vs. heads 12–14 mm long), filaments inserted at the mid-level region of the corolla tube (vs. stamens inserted at the apex of the corolla tube in M. lloensis ), midvein conspicuous (vs. submarginal vein conspicuous in M. lloensis ) and flowers whitish with dull red lobes. This latter character was based on the description of the type specimen.
Similarly, examination of Colombian specimens of Mikania flabellata (Cuatrecasas 12840, COL; García-Barriga 18773, COL; Sanchez 417, COL, HUA; Uribe-Uribe 5573, COL) shows that it differs from the new species in the following characters: narrowly infunfibuliform corollas, leaves puberulent to glabrescent below, with rounded base, and phyllaries 8–11 × 2 mm.
Etymology: —The name of this species is dedicated to Julio Betancur, a Colombian botanist at the Instituto de Ciencias Naturales ( Colombia), and a member of the collecting team of the type specimen.
Conservation: — Mikania betancurii has only been found in the type locality, despite the fact that the area surrounding it has extensively been collected. Thus, it might be considered as restricted to an area less than 100 km 2. Furthermore, that locality is drastically altered due to increasing habitat destruction, grazing and mining. In the absence of populational observations, according to the criteria of IUCN (2013) this species should be considered as belonging to the category of Data Deficient (DD).
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