Ponthieva boliviensis Kolan., Baranow & A. Fuentes, 2019

Kolanowska, Marta, Baranow, Przemysław & Fuentes, Alfredo F., 2019, A new species of Ponthieva (Cranichidinae, Orchidaceae) from Bolivia, Phytotaxa 397 (2), pp. 186-192 : 188-191

Ponthieva boliviensis Kolan., Baranow & A. Fuentes , sp. nov. ( Figs. 1 , 2A )

Species similar to P. pilossisima and P. hermiliae but with long ovary neck, ovate basal lip lobes, ovate lip disc with apical part lacking distinct constriction, and different callus.

Type:— BOLIVIA. Dpto. La Paz. Prov. Franz Tamayo. Región Madidi, Sano Domingo, sector Lechemayu, en la Parcela Permanente 49. 14˚46’09” S 68˚37 ’11” W. Alt. 1475 m. 19 Aug 2010. A. Fuentes et al. 17045 (holotype LPB!; isotypes: LPB) .

Epiphytic plants about 37 cm tall. Leaves 2–3, basal, rosulate, petiolate; petiole up to 4 cm long; blade up to 25 cm long, 4.5 cm wide, narrowly elliptic, acute to acuminate, pilose. Peduncle densely pilose, 2–3-sheathed, terminated by a subdensely many-flowered raceme up to 12 cm long. Flowers large, sepals and petals basally suffused with brownishpink, otherwise whitish, lip yellowish-green, gynostemium yellow. Floral bract about 7.3 mm long, ovate, acute, ciliate. Ovary with distinct neck, 38 mm long, densely pilose. Dorsal sepal 14.2 mm long, 3 mm wide, oblong-elliptic, acute, 5-veined, sparsely ciliate. Lateral sepals free to the base, 18 mm long, 4.3 mm wide, obliquely oblong-elliptic, acute, 5-veined, sparsely ciliate.Petals shortly unguiculate; lamina 18.7 mm long, 4 mm wide, narrowly lanceolate, somewhat falcate, obtuse, 5-veined, glabrous. Lip clawed, ca. 7.2 mm long, 4.2 mm wide, more or less ovate-sagittate in general outline, basally with two ovate-triangular, somewhat spread lateral lobes, apex elongate, subobtuse; disc with two, oblong, parallel, close to each other basal calli (the structures are visible on the fresh material only, on the drief flower look like a single thickening), primarily 5-veined, lateral veins branching. Gynostemium 2.5–3 mm long, subsessile, erect, short, somewhat swollen apically.

Etymology:—In reference to the country of origin of the type specimens.

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Distribution and habitat:—Plants were found growing in a flat terrain near to the Lechemayu river a territory part of the indigenous Leco community of Santo Domingo. This area is located in the Madidi region to northwestern of Bolivia, specifically east of the town of Apolo on the outside and between the protected areas of Madidi to the north and Apolobamba to the south ( Fig. 3 ). The species grows in a Yungenian (Rivas-Martínez et al. 2011) mixed forest-palm grove formation of the upper basimontane altitudinal belt with hyperhumid pluvial bioclimate, characterized mainly by the presence of the Andean palm Dictyocaryum lamarckianum (Martius 1838: 188) Wendland (1863: 161) .

Notes:—The new species is similar to Ecuadorian P. pilosissima ( Senghas 1989: 47) Dodson (1996: 110) and Peruvian P. hermiliae Valenzuela Gamarra (2012: 161) but their differences are summarized in Table 1 and Fig. 3 . All these species are characterized by pilose leaves and free lateral sepals. In most representatives of Ponthieva with hirsute/pilose leaves the lateral sepals are more or less connate.

From P. pilosissima ( Fig. 2 ) the new species can be easily distinguished by the shallowly (vs. deeply) concave lip, ovate-triangular (vs. ligulate) basal lip auricles, which are differently oriented (more or less parallel to the claw vs. widely spreading) and ovate lip disc (vs. triangular in outline). Moreover, in P. pilosissima the lip is brownish-yellow, noticeably constricted in the apical part and here it is distinctly thickened. These characters are absent in P. boliviensis . In P. hermiliae the lip is yellowish-green to greenish-white, lanceolate-triangular, lacking basal lobes, concave on the proximal half, with a 6-toothed callus placed horizontally in front of the basal cavity.

In P. vasquezii Dodson (1989: 287) which is also characterized by villose leaves and free lateral sepals the sepals are dissimilar, lateral sepals are broadly ovate, dorsal sepal is oblong-elliptic, petals are distinctly unguiculate, obliquely ovate above the claw and the lip lacks basal lobes.

Figures

FIGURE 1. Ponthieva boliviensis—A—habit, B—floral bract, C—bract, pedicel and ovary, D—dorsal sepal, E—petal, F—lateral sepal, G—lip, front view, H—lip, side view, I–J—gynostemium, various views (A—photograph of the holotype, B–J—drawn from the holotype).

FIGURE 2. Flowers of Ponthieva boliviensis (A; photo by A. Fuentes), Ponthieva pilosissima (B; photo by A. Hirtz), and Ponthieva hermiliae (C; photo by L. Valenzuela Gamarra)

FIGURE 3. Distribution of Ponthieva boliviensis (star), Ponthieva pilosissima (circle), and Ponthieva hermiliae (square). Map prepared with ArcGIS (Esri).