Pinguicula ombrophila A.J.Perez , Tobar & T.Henning, 2023

Perez, Alvaro J., Tobar, Francisco, Burgess, Kevin S. & Henning, Tilo, 2023, Contributions to Ecuadorian butterworts (Lentibulariaceae, Pinguicula): two new species and a re-evaluation of Pinguicula calyptrata, PhytoKeys 222, pp. 153-171 : 153

Pinguicula ombrophila A.J.Perez, Tobar & T.Henning sp. nov.

Fig. 4

Type.

Ecuador. Zamora-Chinchipe, Cantón Nangaritza, Parroquia Nuevo Paraíso, Reserva Biologica Cerro Plateado , -4.6194445, -78.7830556, 2850-2900 m, 27 Sep 2016, Á.J. Pérez, N. Zapata & W. Santillán 10353 (holotype QCA (fl, fr) barcode: 245582) .

Diagnosis.

Pinguicula ombrophila belongs to Pinguicula sect. Ampullipalatum and is closely allied to the other North Andean species of the section ( P. calyptrata , P. jimburensis and P. rosmarieae ). It differs from P. calyptrata and P. jimburensis in its lithophytic (vs. terrestrial) habit and the combination of broad rosettes with flat leaves (unlike P. jimburensis ) without curled margins (unlike P. calyptrata ). The flowers of P. ombrophila are similar to those of P. calyptrata and a distinct yellow palate - absent in P. rosmarieae and P. jimburensis - is present. It differs from all three other taxa by having very short flower scapes that barely reach leaf-length.

Description.

Lithophyte on sandstone rocky walls, perennial rosette leaved herb with 1 (-3) flowering scapes. Rhizome ~12 mm long, with numerous fibrous roots 1.5-6.5 cm long. Leaves (5-) 6-7, flat on the ground, ± succulent (dried translucent-membranous), (15-) 20-30 (-35) mm long, nearly as long as wide, the blades ovate-obovate-oblong in outline, rounded at the tip, attenuated to the base into a sessile petiole, the margins entire, light green along the midvein and purple-brownish throughout the rest, upper surface of lamina covered with stalked glandular hairs. Hibernacula (winter buds, dormant buds) absent. Scapes 1-2 (-3), erect, (20-) 25 (-30) mm tall, terete, filiform (0.5-1 mm thick), one-flowered, purple-brownish, scattered with stalked glandular hairs. Flowers small, ~10-13 (-15) mm long (including tube-spur-complex). Calyx two-lipped, persistent, purple-brownish, upper surface of sepals scattered with stalked glandular hairs; upper lip deeply divided into three nearly equal-sized oblong lobes, at apex pointed; lower lip deeply divided into two oblong lobes, at apex pointed. Corolla two-lipped, bluish-magenta to bright-violet, scattered with stalked glandular hairs; upper lip two-lobed, lobes obovate, ~5-6 mm long and ~4-6 mm wide, notched at the apex; lower lip larger and longer than the upper lip, with three oblong to obovate-oblong lobes (the median lobe somewhat larger than the two lateral ones), 5-6 mm wide, each distinctly (up to 1/3 of its length) notched. Tube (tube-spur-complex) at the throat funnel-shaped and with dark stripes, proximally getting narrower until the end of the lower calyx lobes and merging relatively abruptly and with a weak angle into the cylindrical stubby, at apex rounded, yellow spur; ~6 mm long; Palate simple, well developed, inserted immediately behind (~1-2 mm) the corollas´ lower-lip middle lobe, yellow, set with short-stalked glandular hairs, proximally elongated into two short ventral hair strips; the corollas´ inner surface covered with small white hairs, stretching proximally along on each side of the inner tube wall. Stamens 2, filaments 1.5-2 mm long, anthers dorsifixed, 0.5 mm, oval, transverse dehiscing. Ovary 1.2 mm, rounded, glabrous, style 1 mm long, stigma 1 mm long, campanulate, sparsely covered with simple trichomes. Capsule 3-4 mm, rounded, glabrous, splitting in 2 valves. Seed numerous, alveolate, ellipsoid, 0.5-0.8 mm long. Chromosome number unknown.

Etymology.

The specific epithet was chosen to point at the particular habitat requirements of the plants. They prefer very wet conditions where they not only receive constant moisture from the surrounding waterlogged paramo-soil, but are also fully exposed to the high amounts of precipitation and fog typical for this area. The name Pinguicula ombrophila signifies “rainloving” from the two latin words “ombros” (rain) and “philos” (that loves/is fond of).

Distribution, habitat and associated vegetation.

The Cerro Plateado Biological Reserve is one of the governmental protected areas along the Cordillera del Cóndor range in Ecuador, protecting around 26 000 ha of mature forest from 850 to 3100 m in the province of Zamora-Chinchipe. The Cordillera del Cóndor runs 150 km north-south along the border of Ecuador and Peru. This mountain range is isolated from the main Andean chain and is geologically distinct, formed with an intermixture of limestone, quartzitic sandstone, and igneous rock of the Hollin Formation ( Gregory-Wodzicki 2000; Neill 2005). The geology of these mountains is similar to the tepuis of the Guyana shield in northwest South America. In fact, a number of angiosperm genera once thought to be endemic to the tepuis of the Guyana shield have also been found along the Cordillera del Cóndor ( Berry et al. 1995; Schulenberg and Awbrey 1997).

Pinguicula ombrophila , together with P. calyptrata (Neill et al. 17467, ECUAMZ; Pérez et al. 10170, 11711, QCA; Figs 2 , 3 ), were collected during the first botanical expedition to the Cerro Plateado led by Dr. David A. Neill in 2012 and later in 2016 and 2021 by the first author of this paper. Both species were collected at the summit of this Andean tepui, very close to the Peruvian border, that correspond to the highest sandstone plateau of the Cordillera del Cóndor, growing as a lithophyte on exposed quartzitic sandstone rocks with acidic and nutrient poor soils and in an extremely wet environment (Figs 2 , 3 ). The vegetation is paramo-like, dominated by the grass Chusquea cf. nana and the bromeliad Vriesea sp. along with scattered shrubs of Clethra concordia D.A.Neill, H. Beltrán & Quizhpe, Diplostephium sp., Gaultheria lanigera Hook. and Valeriana plateadensis sp. nov. Á.J. Pérez, C. Persson & J.N. Zapata ( Persson et al. 2023).

Conservation status.

Only one population with ca. 15 mature individuals of this species was discovered at the type locality at the summit of the Cerro Plateado. It is an isolated area and difficult to access; nevertheless, climate change could affect the environmental requirements of this species. According to the IUCN Red List criteria ( IUCN Standards and Petitions Committee 2022) this species is assessed as Vulnerable (VU, Criterion D2).

Affinities.

P. ombrophila is superficially very similar to P. rosmarieae with which it shares the wide leaves without involute margins and the resulting large and relatively flat rosettes. Interestingly, both P. ombrophila and P. rosmarieae are lithophytic (the latter rarely epiphytic) plants that prefer the wettest of all non-submerse locations available in the generally very moist paramo habitats. The rosette morphology likely is an adaptation to that and might be subject to environmental constraints. P. rosmarieae shows, however, a different flower morphology with a peculiar box-like corolla-spur complex and the lack of a yellow palate. The flowers of P. ombrophila are more similar to P. calyptrata and the three species are obviously closely related to each other. P. ombrophila is furthermore characterized by a very short flower stalk compared to all other north-Andean taxa. The flowers barely exceed the tips of the freshly developing leaves, a character so far only known and typical for, for example, the south-Andean P. nahuelbutensis ( Gluch 2017).

Additional specimens examined

(paratypes). Ecuador. Zamora-Chinchipe. Cantón Nangaritza, Reserva Biológica Cerro Plateado, Herbaceous páramo-like vegetation on broad, gently sloping summit area of Cerro Plateado , 04°37'10"S, 078°46'59"W, 2915 m, 24 Aug 2012 (fl), D. Neill et al. 17465 (ECUAMZ); ibid, colecciones en la cima de la meseta, vegetación paramuna, -4.6194445, -78.7830556, 2900 m, 23 Sep 2016 (fl, fr), Á.J. Pérez et al. 10145 (QCA, barcode: 245583); ibid, 8 Aug 2021 (fl, spirit collection), Á.J. Pérez et al. 11712 (QCA, barcode: 245580) .

Figures

Figure 2. Habitats of the new species and associated P. calyptrata A-C Lagunas Negras de Jimbura A swampy areas between rocks next to the Lagoons where P. jimburensis is found B neighboring stand of P. calyptrata C flower of P. calyptrata, frontal view D-G Reserva Biologica Cerro Plateado D small stand of P. ombrophila growing on a vertical rock face E single plant on top of a rock overhang F rosette of sympatric P. calyptrata G ditto, flower in frontal view. Photos: A-C by Kabir Montesinos; D-G by Alvaro J. Perez.

Figure 3. Map showing the distribution of Pinguicula spp. in Ecuador and illustrating the morphological spectrum of P. calyptrata observed from north to south. The yellow circles mark the respective localities sampled (locality name in italics). The two new species (P. jimburensis = red star, P. ombrophila = green star) are both found at the southern end of Ecuador near the border to Peru and well within the Amotape-Huancabamba Zone (dashed line).

Figure 4. Pinguicula ombrophila A, B flowering plant in fronto-lateral view in the natural habitat in the Reserva Biologica Cerro Plateado C flower, frontal view D ditto, lateral view E freshly collected specimen, note the angled spurs with the blunt apices F young capsule. (A-F from A. J. Perez et al. 10353). Photos by Alvaro J. Perez.