Passiflora yolandae Kuethe & Montesinos, 2023

Kuethe, J. R., Montesinos, Kabir, Garzón-Suárez, Henry X. & Jost, Lou, 2023, A large new species of Passiflora, supersect. Laurifolia, ser. Quadrangulares (Passifloraceae) from the sub-Amazonian forests of Ecuador, with notes on its taxonomic alliance and distribution, Phytotaxa 619 (4), pp. 277-284 : 278-282

Passiflora yolandae Kuethe & Montesinos sp. nov. ( Figures 1–3 )

Type: — ECUADOR. Tungurahua province: cantón Baños de Agua Santa, parroquia Río Negro, Vía Puyo—Baños , km 66, 1°24’42.1”S, 78°11’14.1”W, 1185 m, 26 July 2023, H. Garzón & J. Mendonza 222 ( HT: HUTPL) .

Diagnosis: —This new species is similar to Passiflora alata and P. quadrangularis , from which it differs by its long (> 10 cm) pendent inflorescences (vs semi-horizontal to short semi-pendent), the number and position of the petiolar nectaries (apical 4–5 vs scattered 6–8 in P. quadrangularis or scattered 2–4 in P. alata , the lavender pink-purple colour of the flowers (vs. red to reddish purple), the near perfect globular shape of the buds during the early budding stage (vs. oblong to ovate), and the reflexed bracts during the budding stage (vs. down facing).

Description: — Large liana, with trailing branches 5–10 m long, glabrous throughout. Stems sturdy, green, deeply triangular, intermediate and older stems weakly wooded. Tendrils green, strong. Stipules 10–12 × 2–3 mm, foliaceous, lanceolate to narrow lanceolate, acute at apex, green, margins entire. Internodal distance 7–17 cm. Petioles 7.8–8.5 cm long, caniculate to terete, with 2 pairs of opposite glands present in the upper half of the petiole, upper pair borne 3–7 mm below the base of the blade, occasionally a fifth gland present borne asymmetrically 2–3 mm below the lower pair, pairs present 10–14 mm apart; glands 2–3 mm in diameter, cup-shaped, sessile, green to greenish-black. Leaf blade 20–25 × 12–14 cm on older stems, 14–16 × 7–8 cm on flowering branches, ovate, thick coriaceous, acute to acuminate at apex, cuneate at base, deep green on both surfaces, margins entire, veins elevated on the lower surface. Inflorescence axillary on younger branches, showy, singular, with long pendent flowers. Peduncles 10.5–12 cm long, pendent, articulated 13–15 mm below the base of the flower. Bracts 28–30 × 22–24 mm, ovate to cordate when flattened, foliaceous, recurved and facing upright with the margins folded inwards giving them a concave appearance, green. Buds round to oblong, green, smooth. Flower 10–10.5 cm in diameter, very showy, purple to lavender, sweetly scented. Hypanthium 25–26 mm wide, 4–5 mm high, shallow campanulate, green without, white within; sepals 34–36 × 18–20 mm, oblong, fleshy, rounded at apex, purple to lavender internally, green externally, ecorniculate, white and spongy when broken; petals subequal to sepals, 35–36 × 13–15 mm, oblong to narrowly oblong, membranous, rounded at apex, purple to lavender on both sides. Corona arranged in 4–5 series, the outer two series the most pronounced, white with purple bands; the two outer series subequal in length, 36–38 mm long, liguliform, wavy at apex, with 7–8 purple bands equally distributed across its length; the two inner series 2–2.5 mm long, filiform, white with a purple tip, erect; innermost series slightly longer, 2.5–3 mm, facing inwards towards the androgynophore; operculum distinct, 9–10 mm long, thick, formed from the fusion of linear segments presenting 5 wall-like structures, strongly facing inwards forming a physical barrier around the androgynophore, white with 2 purple bands, purple at apex. Trochlea present, 8–9 mm wide, forming a swollen center with a purple membrane, white at base. Limen 5–6 mm long, recurved upwards forming a membranous barrier, purple to black, white to translucent at base, margin serrulate; nectar chamber creamish-yellow, partially divided into 2 chambers; androgynophore 13–14 mm tall, white with reddish specks on the anthers. Ovary 8 × 5 mm, oval, glabrous, yellowish; stigmas 11–12 mm, stamen 2-parted, 6 mm long; filaments green with red speckles; anthers creamy white. Fruit (immature), oval, green. Seeds not seen.

Phenology: —This species has been observed with flowers between December and February, and expected to carry its fruits from December into March. Large bumble bees and carpenter bees were seen visiting the flower, though it is not confirmed whether those are the effective pollinators.

Distribution and habitat: — Passiflora yolandae is endemic to the sub-Amazonian transitional forests of east-central Ecuador. Here it was found in the premontane cloud forests of the provinces of Napo, Tungurahua, Morona-Santiago and Pastaza, which are marked by dense primary vegetation adapted to metamorphosed igneous clays and soils. Noteworthy populations were seen in the Mera region, where it was found growing along the road from Puyo to Baños; the small track to Cuevas del Río Anzu; the track between Río Anzu and Río Chóferes; and the road between Finca de la Vaca and Finca Durán. Additional populations were seen near the city of Tena, and in the Narupa Reserve south of the Sumaco volcano, Napo province (see Fig. 3 ). In the Sumaco location, it was found growing in a riparian ravine next to a waterfall in dense, sub-Amazonian forest. This species is generally found growing on the east-facing slopes at elevations between 1100 and 1500 m, where it was seen dominating the forest canopy, trailing down long branches at roadsides, forest clearings and riverbanks.

Etymology: —This species is dedicated to the late Yolanda González Montesinos; the mother of the second author, whose pure spirit resembles the purity and beauty of this Passiflora .

Conservation notes: — Passiflora yolandae is presently known from just 9 collections (from four to five distinct populations), all restricted to the east-facing slopes of the east-central Ecuadorean Andes. Three of the unvouchered collections (from georeferenced photographs) were found within the peripherals of National Parks or biological reserves, being the frontal Andean ranges of the Parque National Antisana, Sumaco-Napo-Galeras and the peripheries of the Llanganates, respectively. Most of the vouchered collections were found along the forested road between Baños and Puyo, which is not protected as a reserve per se, although the steep topography of the region would make agricultural development unlikely. This area between Baños and Puyo has been recognized as an important center of plant and animal endemism and was declared a “Gift to the Earth” by the World Wildlife Fund ( Jost & Shepard 2011, Jost & Iturralde 2017, Reyes-Puig et al. 2022, Arias-Gutierrez et al. 2023). Plotting those georeferenced points in GeoCat software gives a total Area of Occupancy (AOO) of about 36 km 2 and an Extent of Occurrence (EOO) of 1228 km 2, classifying Passiflora yolandae as EN (Endangered) for both categories in line with the IUCN (2017) criteria adhered to by the software. This is further supported by the IUCN (2021) criterion B1a quantifying a 5,000 km 2 threshold; and criterion C2a quantifying an estimated total population of less than 2,500 mature individual plants and a decline caused by its fragmented distribution and habitat disappearance.

Its restricted endemic distribution to the fertile eastern slopes of the Ecuadorean Andes poses a potential risk for its long-term conservation. However, Ecuador is taking steps towards becoming more ecologically conscientious, encouraging eco-tourism companies, and allocating regions for biological preservation. Being found close to areas of great touristic potential (the cities of Baños, Tena and Puyo), should further encourage the preservation of its surrounding forests, which includes a large proportion of the range of P. yolandae . Finally, given its taxonomic association to the widely cultivated P. alata and P. quadrangularis , the fruit and ornamental value of P. yolandae are likely to yield further benefits for local growers, and can potentially provide new genetoic material to improve the commercially cultivated species.

Paratypes:— P. yolandae : ECUADOR. Napo: Sumaco Napo-Galeras National Park, Reserva Narupa, Río Hollin , next to a small waterfall, 1294 m, 22 December 2018, Montesinos s.n. ( HA); Tena region, road towards Reserva Colonso Chalupas , 1000 m, 12 December 2022, Kuethe, J.R., Molinari, M., Bernal, H.D. s.n. ( QCA); Tena region, near Laguna Verde Sacha Ursay, small road from Tena to Ramicocha , 770 m, 12 December 2022, Kuethe, J.R., Molinari, M., Bernal, H.D. s.n. ( QCA); Río Quile, Mera-Cashurco, 1100 m, date unspecified, Asplund 19330 ( S); Mera , 1160 m, date unspecified, Harling 3788 ( GB, S, UPS); Mera , road from Puyo to Baños , 1450 m, 13 December 2022, Kuethe, J.R., Molinari, M., Bernal, H.D., s.n. ( QCA); Mera, the small track to Cuevas del Río Anzu 1150 m, 14 December 2022, Kuethe, J.R., Molinari, M., Bernal, H.D. s.n. ( QCA); Mera, the track between Río Anzu and Río Chóferes 1450 m, 13 December 2022, Kuethe, J.R., Molinari, M., Bernal, H.D. s.n. ( QCA); Pastaza: the road between Finca de la Vaca and Finca Durán , just across the bridge over the Río Pastaza 13 December 2022, Kuethe, J.R., Molinari, M., Bernal, H.D. s.n. ( QCA); Tungurahua: Road Baños—Mera, Cashurco , 1300 m, 14 February 1984, Knapp & Mallet 6275 ( US) .

Figures

FIGURE 1. Passiflora yolandae sp.nov., here seen in the Río Anzú region. A) Habit showing the long pendent peduncles; B) detail of the large flower; C) the globular pendent buds with reflexed bracts; D) detail of the leaf; E) flower in longitudinal section; F) detail of the petiolar nectaries; G) detail of the lanceolate stipules. Compiled from the photographs taken by J.R. Kuethe.

FIGURE 2. Direct comparison between Passiflora yolandae sp.nov. (A); P. carajasensis (B); P. alata (C); and P. quadrangularis (D). Note substantial difference in length, floral colour, shape of the buds and petiolar nectaries. The material for P. yolandae taken from Narupa Reserve—Ecuador. The material for P. alata taken from a cultivated plant in the Latacunga region. Photographs of P. carajasensis and P. quadrangularis taken in Brazil. Photo courtesy by Kabir Montesinos (A), J.R. Kuethe (C) and André Cardoso (B and D).

FIGURE 3. Distribution and collection sites of Passiflora yolandae sp.nov. A possible lateral distribution based on contiguous habitat and elevation indicated in red. Inset showing the position within Ecuador. Note how this species is restricted to the eastern Andes of Central Ecuador.