Passiflora rosacea Kuethe & Justiniano, 2023

Kuethe, J. R. & Justiniano, Hermes, 2023, Establishing the true identity of Passiflora nephrodes (Passifloraceae), resulting in Passiflora rosacea, a new species from Santa Cruz, Bolivia, Phytotaxa 600 (2), pp. 84-94 : 88-91

Passiflora rosacea Kuethe & Justiniano sp. nov. ( Figures 1 , 2 , and 4)

Type:— BOLIVIA. Santa Cruz: Ichilo, Buena Vista , 17°26’29.5”S, 063°39’43.7”W, 355 m, 7 February 2021, H. Justiniano et al. 50 (Holotype: USZ! Isotype: MO!) .

Diagnosis: —This new species is closely related to P. nephrodes and P. gardneri , from which it differs by its rose-pink floral colour (opposed to lavender-purple) and vegetative indument (hirsute opposed to glabrescent for P. gardneri to pilose for P. nephrodes ). The flowers of P. rosacea further differ from these abovementioned species by having the inner coronal series reaching less than 3 mm long (opposed to 3–7 mm in length), and the operculum reduced to 2–3 mm long (opposed to 7–8 mm in length).

Description: —Plant sparsely to moderately hirsute throughout, 5 m long or longer. Stem cylindric. Stipules semi-ovate, 1.5–2.0 × 0.5–1.5 cm, aristate, coarsely serrate-dentate. Petioles 3–5 cm long, bearing 2–6 stipitate glands, ca. 1.5 mm long in pairs or slightly alternate along the petiole. Leaves 6.5–16.5 × 7–15 cm, 3-lobed; middle lobe ovate or ovate-lanceolate, up to 10.5 cm long, 2–5.5 cm wide near base, two-thirds the length of the blade, acute or sub-obtuse, the lateral lobes deltoid-ovate, subcordate. Peduncles 2.5–8 cm long, borne singly or in pairs. Bracts borne about ca. 2 mm below the base of the flower, ovate-lanceolate, ca. 0.6 × 0.2 cm, serrate. Flowers rose-pink, 4.5–6.9 cm across. Hypanthium cup-shaped, 5.5–6 mm in diameter, ca. 2 mm in depth, pale green outside and inside. Sepals oblong, 2.6– 3.0 × 0.8–1.0 cm, rose pink internally, light green externally, obtuse, dorsally awned just below apex, nerve dorsally pilose along to the awn, awn 1.5 mm long. Petals linear-oblong, 1.7–2.5 × 0.5–0.9 cm, rose-pink on both sides, slightly shorter and narrower than the sepals. Corona filaments filiform, in 6 series, the outermost series with filaments 2.0– 2.5 cm long, the second ones 1.8–2.1 cm long, both radiate, basally pink turning purple the remaining 2/3, with one or two broader white bands and one narrow white band, turning white distally towards the apex; the third series semi-erect, capitate, ca. 3 mm long inclined outwardly, light rose-pink, the fourth series same colour, slightly shorter, both capitate; the inner two series slightly capitate, ca. 2 mm long, upright, pink basally, white distally. Operculum membranous at base, filamentous above, the filaments 1.5–2 mm long dark pink basally, white distally. Limen membranous, ca. 3 mm high, closely surrounding the base of the gynophore, dark pink, distally clearer. Gynophore 1.0 cm long, speckled light green with dark red spots. Ovary ovoid, glabrous, ca. 5 × 3 mm. Fruit oblong, ca. 7–8 × 3 cm, narrowed at base, aril sweet and eaten by humans. Seeds cordate, pitted on both sides, ca. 4 × 7 mm.

Phenology:— This species has been found in flower between January and June, corresponding to the wet season and beginning of the dry season in southern Bolivia. In cultivation, this species produces flowers year-round, provided there is enough humidity and water available. Observations from both in situ sightings and cultivated plants have shown that the flowers are visited by medium-sized bumblebees and bees.

Etymology:— The specific epithet is derived from the Latin conjunction: “Rosa” and “roseum”, meaning “rose-pink”, referring to the colour of the flower.

Distribution and habitat:— Passiflora rosacea is a narrow endemic found in the Santa Cruz and Chuquisaca departments of Bolivia. It was found on the east-facing Andean slopes of the premontane Andean region, with specimens seen along the continuous mountain-ridges from Amboro to Vallegrande (Santa Cruz department) and in the Chuquisaca department nearby the townships of Monteagudo and San Pedro de Huacareta. Populations appear to be very small and limited in extent, growing in seasonally humid premontane forest at elevations between 360 m at Buena Vista and 1,200 meters at Monteagudo; and up to about 2,190 meters in the Mairana Valley. Passiflora rosacea is a moderate climber that can be found along the edges of secondary forest next to roads, forest tracks and forest clearings.

Conservation notes:— Passiflora rosacea is a very narrow endemic that was found in a small region in premontane Andean Bolivia. There are only six collections of the species, marking Passiflora rosacea as a relatively rare species with a low abundance in its natural habitat. The populations are somewhat scattered, but a few populations have been found in the Amboro and Inao National Parks or protected reserves. However, the majority of populations are currently found in areas at potentially high risk of habitat fragmentation, where habitat clearing and agricultural development are prominent. From the current collections, the EOO is calculated to be about 3,500 km 2 with a AOO of just 28 km 2. For those reasons, P. rosacea is assigned a preliminary status of EN (Endangered) based on IUCN (2022) criterion EN(B1ab[iii], B3 and C1).

Additional specimens examined:— Passiflora rosacea sp.nov. BOLIVIA. Santa Cruz: Florida , 18°04’13”S 063°55’08”W, 2,190 m, 15 November2004, M.Serrano et al.5,477 ( HSB, MO) ; Vallegrande , 18°46’19”S 063°53’39”W, 1,941 m, 31 March 2006, R. Hurtado 662 ( LPB, MO, USZ) ; Chuquisaca: Hernando Siles , 19°55’43”S 064°13’52”W, 1,598 m, 27 December 2007, J. Villalobos 1,151 ( MO) ; Hernando Siles , 19°50’59”S 064°06’39”W, 1,795 m, 19 April 2008, J. Villalobos et al. 1,622 ( MO) ; Hernando Siles , 20°19’46”S 064°02’32”W, 1,854 m, 26 December 2005, M. Serrano et al. 6,961 ( MO) ; Ichilo , 17°26’29.5”S, 063°39’43.7”W, 355 m, 7 February 2021, H. Justiniano et al. 50 ( USZ) .

CULTIVATED. English National Passiflora Collection, United Kingdon, R.J.R. Vanderplank. PassifloraHoeve, Harskamp, The Netherlands, P. Moerman & A. Lommen. Swiss Passiflora Collection, Switzerland, M. Varga. National Italian Passiflora Collection, Italy, M. Vecchia. In Buena Vista, Santa Cruz, Bolivia, R. Vargas & S. Vargas. In Santa Cruz, Santa Cruz Bolivia, H. Justiniano.

Figures

FIGURE 1. A–C Passiflora rosacea Kuethe & Justiniano sp. nov. A) The fully open flower during anthesis; B) detail of the foliage, pilosity and foliaceous stipules; C) detail of the fruit, note the difference in pilosity of the stems; D–F Passiflora nephrodes Mast. D) The fully open flower during anthesis; E) detail of the foliage, pilosity and foliaceous stipules; F) detail of the fruit, note the dense pilosity of the stems. Photograph courtesy by A) Ramon Vargas; B–C) Hermes Justiniano; D–E) Martin Apaza; F) Alfredo Fuentes.

FIGURE 2. Longitudinal sections of the members of Passiflora subg. Passiflora supersect.Stipulata ser. Menispermifoliae Killip ex Cervi from Bolivia and Brazil.A) Passiflora nephrodes Mast.; B) Passiflora rosacea Kuethe & Justiniano sp. nov.; C) Passiflora menispermifolia Kunth; D) Passiflora gardneri Mast. Photograph courtesy by A) Martin Apaza; B) Hermes Justiniano; C) Miguel Molinari; D) André Cardoso.