Triolena vasquezii Michelang. & R.Goldenb., 2018

Michelangeli, Fabián A. & Goldenberg, Renato, 2018, New and noteworthy Melastomataceae from the Yanachaga-Chemillén National Park and surrounding areas in Oxapampa, Pasco, Peru, Phytotaxa 374 (3), pp. 185-210 : 203-206

6. Triolena vasquezii Michelang. & R.Goldenb. sp. nov. ( Figures 12–13 )

Diagnosis:—Differs from Triolena pustulata Triana (1871: 81) due to the shorter trichomes in the adaxial surface (0.5–1 mm vs. 1.5–3 mm long in T. pustulata ) and stamens with two ventral appendages (vs. three in T. pustulata )

Type:— PERU. Pasco: Province of Oxapampa, Dist. Pozuzo, Parque Nacional Yanachaga-Chemillén, sendero Pan de Azúcar , ca. 4 km al sur del puesto de control Huampal, 1145 m, 10°11’48.8”S, 75°35’15.2”W, 18 March 2016, F. A. Michelangeli et al. 2705 (Holotype: USM!; Isotype: NY!) .

Rhizomatose herbs 20–40 cm tall. Stems terete, densely covered with 0.3–2.5 mm long, unbranched, appressed trichomes, the larger ones slightly flattened. Leaves opposite, strongly anisophyllous to subisophyllous, when anisophyllous the big leaf in each pair with petioles 10–34 mm long, blade 8–15 × 2–5.5 cm, the small leaf in each pair with petioles 1–3 mm long, blade 4–6.7 × 1.6–2.4 cm, when subisophyllous similar to either the big or the small ones described above; leaves always lanceolate to elliptic-lanceolate, the apex long acuminate, base acute to narrowly rounded or even narrowly cordulate, often asymmetric, margins denticulate-ciliolate to serrulate-ciliolate, acrodomous nerves 5 to 7, sometimes with an additional, thin, submarginal pair, suprabasal (the inner pair of secondaries joining the midvein 3–16 mm above the base), midvein, secondaries, tertiary veins and reticulation impressed on the adaxial surface and prominent on the abaxial surface; adaxial surface deep green, with a lighter-green to whitish stripe along the midvein, bullate and with sparse to moderate (mostly right on the bullae), 0.5–1 mm long, unbranched, appressed trichomes, plus similar, but denser and larger, 1–5 mm long trichomes on the nerves; abaxial surface purple with a greenish stripe along the midvein, foveolate, moderately covered with trichomes similar to those on the branches, mostly on the nerves and reticulation (and absent inside the foveolae). Uniparous cymes 5–8 cm long, 7–10-flowered, apical, turning lateral due to development of axillary branches, the axis reddish, covered with the same indument as the branches; bracteoles lacking. Flowers on short pedicels ca. 1 mm long, 5-merous. Hypanthium 2.3–2.9 × 2.7– 3.1 mm, campanulate, green but densely covered with reddish trichomes, similar to the ones on young stems and inflorescences, inside glabrous, torus glabrous. Calyx tube 0.4–0.6 mm long, greenish, covered with the same reddish trichomes as the hypanthium; sepals internal laminae 0.9–1.1 mm long, widely triangular, the apex broadly acute, margins entire; sepals external projections 1.8–2.3 mm long (setula included), longer than the laminae, triangular, the apex acute and tipped with a setula 1.3–1.6 mm long. Petals 5.9–6.2 × 2.7–2.9 mm, obovate to oblanceolate, apex acute to obtuse or broadly acuminate, margin crenulate-serrulate (but entire near the apex), glabrous, white and pink tipped. Stamens dimorphic, yellow; antesepalous with filaments 3–3.2 mm long, glabrous, anthers 1.1–1.3 mm long, oblong, the pore ca. 0.2 mm diam., apical, connective barely prolonged below the thecae, ventraly projected into two very long appendages, 2.3– 2.6 mm long, erect (but slightly bending backwards), filiform, apex rounded, glabrous; antepetalous with filaments 2.4–2.6 mm long, glabrous, anthers 1–1.1 mm long, widely oblong, the pore ca. 0.2 mm diam., apical, connective barely prolonged below the thecae, ventraly projected into two short appendages, 0.4–0.6 mm long, erect, narrowly triangular, acute, glabrous. Ovary 3-locular, ½–completely inferior, the apex with a collar around the base of the style 0.7–1 mm tall, glabrous; style 4.4–5.3 mm long, straight but slightly curved at the apex, glabrous, stigma rouded and long-papillose. Fruits capsular, triquetrous, 5–6 × 5.7–6.7 mm.

Paraypes:— PERU. Pasco: Province of Oxapampa, Distrito Pozuzo, Parque Nacional Yanachaga-Chemillén , Sector Huampal , Pan de Azúcar , 1000–1100 m, 10°11’05”S, 75°34’51”W, 22 July 2006 (fl, fr), L. Cardenas & V. Flores 600 ( HOXA!, MO!, USM!) ; cerca de la quebrada Pan de Azúcar , 1100 m, 10°11’05”S 75°34’51”W, 8 August 2007 (fl, fr), L. Hernani & A. Peña 217 ( AMAZ, HOXA!, HUSA, HUT, MO, USM!) ; carretera Huancabamba-Pozuzo , 12–13 km al N de Tunquí, 10.1961°S 75.5877°W, 1175 m, 23 July 2017 (fl, fr), F. A. Michelangeli et al. 2916 ( HOXA!, NY!, USM!) ; carretera Huancabamba-Pozuzo, sendero Pan de Azúcar , 1175 m, 10.1878°S 75.5877°W, 16 February 2018 (fl, fr), F. A. Michelangeli et al. 2928 ( HOXA!, NY!, USM!) ; Puesto de Control Huampal , 1100 m, 10°11’S 75°34’W, 12 August 2003 (fl, fr), R. Rojas 1234 ( HOXA!, HUT, MO, MOL, USM) ; camino a Pozuzo , remanentes de bosque, 1200–1480 m, 10°04’02”S 75°32’59”W, 2 June 2004 (fl, fr), R. Rojas et al. 2508 ( HOXA!, MO, NY!) ; Estación Biológica Huampal, trocha Pan de Azúcar , parte baja, 1056 m, 10°11’42”S 75°35’17”W, 26 April 2012 (fl, fr), R. Rojas et al. 7971 ( HOXA!, HUT, MO, MOL, NY!, USM). Distrito Palcazú, atras camino al convento, 375–635 m, 10°09’30”S 75°19’34”W, 9 September 2008 (fl, fr), L. Valenzuela et al. 11984 ( HOXA!, HUT, MO!, MOL, NY!, USM!) ; trocha Robin Foster, Pan de Azúcar , 18 August 2009 (fl, fr), 1189 m, L. Valenzuela & J. L. Mateo 13331 ( HOXA!, HUT, MO, NY!, USM) ; puesto Huampal, bosque remanente en borde de carretera, 1148 m, 10°10’59”S, 75°34’26”W, 10 August 2007 (fl, fr), R. Vásquez et al. 32650 ( AMAZ, HOXA!, HUT, MO!, MOL, NY!, USM). Palcazú valley, Rio San José in the Rio Chuchurras drainage, 600m, 12 May 1983 (fl, fr), D. N. Smith 3981 ( MO!, USM!) .

Distribution, ecology, and phenology:— Triolena vasquezii grows along cliffs and rocks in shaded and moist areas in river canyons at 375–1200 m elev. ( Figure 11 ). It has been found flowering and fruiting throughout the year.

Conservation Status:— Triolena vasquezii is known from three areas, two along the Huancabamba River and one in the Chuchurras River drainage. It has an EOO of 197.12 km 2 and an AOO of 16 km 2. Given the specific habitats where it grows, the number of populations known, and the fact that two of these localities are outside of the National Park in areas under a severe logging pressure, we recommend that this species is considered as Endangered ( IUCN 2001; IUCN Standards and Petitions Subcommittee 2017).

Etymology:—It is an honor to dedicate this species to Rodolfo Vasquez, who has for over 30 years made an incredible contribution to the knowledge of the flora of Peru through his collections and education, and who has spearheaded the study of the plants of the Yanachaga-Chemillén National Park.

Comments:— Triolena vasquezii mostly resembles T. pustulata Triana (1871: 81) , a species found in Ecuador and northern Peru, due to the leaves with bullate adaxial surfaces. However, the leaves of T. vasquezii have shorter trichomes on the adaxial surface (see diagnosis above) and the leaves tend to be proportionally narrower (2.7–3.3 times longer than wide in T. vasquezii vs. 1.8–2.5 times longer than wide in T. pustulata ). In most specimens, the bullae in T. vasquezii are smaller and denser than in T. pustulata . Lastly, the flowers are very similar in appearance and size, but notably, T. vasquezii antesepalous anthers have two ventral appendages, while T. pustulata has three. This would mean that these two species, in spite of their similarities, would have been placed in different genera under the old generic limits, with the species described here placed in Diolena .

Figures

FIGURE 11. Distribution of Triolena rojasae, Triolena vazquezi and Wurdastom ecuadorense (in Peru).

FIGURE 12. Triolena vasquezii. A. Plant. B. Inflorescence apex. C. Flower bud. D. Petals, adaxial surface. E. Flower, longitudinal section, petals and four stamens removed. F. Hypanthium plus ovary, apical view (left), longitudinal section (right). G. Stamens, from left to right, antesepalous—lateral view, antepetalous—lateral view, antesepalous—dorsal view. antepetalous—dorsal view, antesepalous— ventral view, antepetalous—ventral view. H. Young fruit, longitudinal section. I. Fruits, apical view. A. Valenzuela 11984 (NY); B–I. Michelangeli 2705 (NY, spirit collection).

FIGURE 13. Photos of Triolena vazquezi in the field. A. Fertile plant. B. Leaf, abaxial surface. C. Inflorescence apex. D. Flower, apical view. E. Fruits. A, C. Michelangeli 2916. B, D–E. Michelangeli 2705.