Lepanthopsis bennettii Rykaczewski, Baranow, Kolan., 2017

Rykaczewski, Max, Baranow, Przemysław & Kolanowska, Marta, 2017, A new species of Lepanthopsis (Orchidaceae, Pleurothallidinae) from Peru, Phytotaxa 311 (3), pp. 225-234 : 225-227

Lepanthopsis bennettii Rykaczewski, Baranow, Kolan. , sp. nov. ( Figs. 1–2 )

Type:― PERU. Amazonas: Cloud forest. Ex cult . Peruflora sub Rykaczewski et al. 44 (holotype, UGDA! (dried specimen: fragment of plant with flowers); isotypes UGDA!—flowers in alcohol, dried specimen, photographs and drawings, USM!—dried specimen, photographs, drawings) .

Diagnosis:―Species similar to L. trulliformis but distinguishable by long-connate, non attenuate lateral sepals, broadly ovate dorsal sepal, the ovate (vs trullate) petals and the large lip basal lobes.

Small, about 9 cm tall, epiphytic, densely caespitose plant. Roots slender. Ramicauls 2.5‒5.5 cm long, erect, nonproliferating, enclosed by 4‒6 tubular, lepanthiform sheaths. Leaf 1.5–3 × 0.5‒1 cm, oblong-elliptic, acute, thick. Inflorescence 11 mm long, single-flowered. Flower dark purple. Floral bracts 2‒3 mm long, tubular. Pedicel 3 mm long. Ovary 2 mm long. Dorsal sepal 4‒4.2 × 1.8‒2.3 mm, broadly ovate, acute, acuminate, margins entire, glabrous, 3-veined. Lateral sepals 3.5‒3.8 × 2 mm, connate together to 2/3 of their length, synsepal 3.8 mm wide, broadly ovate, shortly acuminate, margins entire, glabrous, 2-veined. Petals 3.2 × 1.7‒2 mm, trullate, acute, shortly acuminate, margins entire, glabrous, 1-veined. Lip 2‒2.3 × 1.5‒2 mm, suborbicular-cordate in outline, apex rounded with basal lobes surrounding the gynostemium, lobes rounded, as long as the middle lobe, disc 3-veined. Gynostemium 0.5 mm long, footless, stout, terete. Anther apical. Stigma entire, apical. Pollinia 2, narrowly oblong-obovoid, apically attenuate.

Etymology:―Dedicated to David E. Bennett (1923‒2009) co-author of Icones Orchidacearum Peruviarum.

Comments: ―The new species resembles Bolivian L. trulliformis from which it differs in the lateral sepals connation (connate to 2/3 vs 1/5 of their length), the broadly ovate dorsal sepal (vs ovate-triangular, long-attenuated towards the apex), the large lip basal lobes which are subequal in length to the middle lobe (vs shorter than the middle lobe) and shorter (3.2 vs 4.5‒5 mm) petals which are about twice longer than wide (vs 3 times longer than wide) and short acuminate (vs long-attenuated towards the apex). From two other representatives of Lepanthopsis subgen. Microlepanthes with single-flowered inflorescence, widely distributed L. apoda and Colombian L. dewildei , the new species is easily distinguishable by the petals form (trullate vs ovate) and large lip lateral lobes. The comparative morphology of all species belonging to Lepanthopsis subgen. Microlepanthes characterized by the presence of single-flowered inflorescence and their floral characters are illustrated in Fig. 3 .

Habitat, ecology and distribution:―This species is known exclusively from the Peruvian Andes. The type collection was prepared based on the plants purchased from Peruflora. The information about habitat of this species was verified during field studies conducted in northern Peru. It was found in high-montane cloud forest edge at the elevation of 3363 m growing sympatrically with species of Stelis Swartz (1799b: 239) and Pachyphyllum Kunth (1816: 338-339) . Flowering in natural habitat occurs in February.

Figures

FIGURE 1. Lepanthopsis bennettii sp. nov. A. Habit. B. Flower, front view. C. Flower, back view. D. Dorsal sepal. E. Lateral sepals. F. Petals. G. Lip. Drawing by Przemysław Baranow.

FIGURE 2. Lepanthopsis bennettii sp. nov. A. Leaf with a flower. B. Flower, front view. C. Flower, side view. D. Lip. Photos by Marta Kolanowska.

FIGURE 3. Comparison of floral segments and habit of the single-flowered species of Lepanthopsis. 1. L. apoda 2. L. dewildei. 3. L. trulliformis. 4. L. bennettii sp.nov. A. Dorsal sepal. B. Lateral sepals. C. Petal. D. Lip. Redrawn from Luer 1994, figs 33 & 38 (permission granted by Missouri Botanical Garden Press, St. Louis). Drawings by by Przemysław Baranow.