Passiflora nana J. M. MacDougal, 2020

Passiflora nana J. M. MacDougal View in CoL , sp. nov.

TYPE: PERU. Cajamarca: San Ignacio Province, Distrito Huarango, El Triunfo , 05°13’S, 78°43’W, 1500 m, 11 July 1996 (bud, fl, fr), José Campos de la Cruz & Pacifico Díaz 2921 (holotype: MO 6147701 [barcode] MO-1183892 GoogleMaps ; isotype: MO 6147702 [bc] MO-1183893 GoogleMaps ). Figures 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 .

Haec species a congeneris fere omnibus statura minuta saepe minus quam 2 m longa atque androgynophoro minus quam 5 mm longo, a speciebus fere omnibus ad Passifloram subg. Decalobam (DC.) Rchb. pertinentibus planta trichomatibus albis rectis saepe plus quam 2 mm longis in partibus omnibus pilosa distinguitur; quoad flores Passiflorae erythrophyllae Mast. similis, sed ab ea petalorum cum sepalis proportione minore, corona interiore longitudine operculum subaequante atque ovario longipiloso distinguitur.

Diminutive climbing vine 1–2.2 m long, densely long pilose or softly hispidulous throughout with straight slender pellucid white rather stiff trichomes (0.5–)1.5–3.5(–4.8) mm long. Stem with cernuous growing apex, subterete, ca. 2 mm diam., striate, with most trichomes at least 2.0 mm long. Prophyll of axillary vegetative bud 1, lanceolate, long acuminate, ca. 1–1.8 × 0.5–0.7 mm, ovate-lanceolate, long acuminate, with trichomes abaxially, drying reddish brown. Stipules 3.0–6(–8.5) × 0.3–1.0 mm, linear to linear triangular, straight or subfalcate, spreading, green, adaxially glabrous, abaxially lightly pilose. Petioles (1.2--)1.5–3(–3.8) cm, glandless, green or flushed with purplish red; laminas 1.6–4.5 long (central vein length) × 2.0– 6.4 cm wide, depressed to widely depressed obovate in outline, ratio of lamina width/length 1.2–1.6, broadly rounded to rounded slightly cuneate at the base, often flushed with reddish purple beneath, entire, conspicuously ciliate at the entire margin with straight trichomes 1–3 mm long (mostly ca. 2 mm long), very shallowly (2)3-lobed, lateral veins equal to central vein, or slightly longer, ratio of lateral/central vein length 1.0–1.3(–1.8), lateral lobes rounded (rarely subtruncate or slightly retuse), central lobe very broadly or obtuse-rounded to more commonly truncate, occasionally slightly or obscurely retuse, or absent, the angle between the lateral lobes veins (51°–)55°–70°(–74)°, laminar nectary glands (2 to) 4–6 per leaf, 0.3–0.8 mm diam., with 2 in axils of the lateral and central veins, but not completely filling the axils, and 0–4 additional glands between the primary veins in proximal ½ (to 2/3) of the leaf. Peduncles (1)2 per node, 8–20(–30) mm long not including floral stipe, slender, uniflorous; bracts 1 or 2 (rarely 3), 1.3–2.5 × 0.1–0.2 mm, setaceous to linear, drying dark, at or within 3(–8) mm of the apex of the peduncle, the most proximal bract noticeably larger; floral stipe ca. 1.5 mm (to 4 mm in fruit). Flowers ca. 1.5 cm diam., light greenish to pale greenish yellow, with a purple operculum; hypanthium 3.0– 5.7 mm diam., concave 1.2–1.5 mm deep at insertion of stipe; sepals (7–)9–11.5 × (2.0–) 2.5–3.5 mm, narrowly triangular–oblong or lanceolate-oblong, obtuse, sparsely pilose abaxially, very pale yellowish green to near white, completely reflexed at full anthesis; petals ca. 2.5–4.4 × 1–1.5 mm, ovate-oblong to narrowly ovate-oblong, white; coronal filaments in 2 series, the outer ca. 33 in number, (3–)4.5–6.5 × 0.25 mm, filiform, pale greenish yellow basally, pale to light dull yellow distally, united and adnate to sepals at very base, spreading widely and strongly reflexed at full anthesis, slightly curved toward the tips; filaments of the inner series 1.6–1.8 mm long, capilliform, slightly clavate apically, erect and close to operculum, pale purplish; operculum 1.5–2.0 mm high, incised 1/4–1/3 its length, ca. 4.5 mm outside diam., light purple to violet, membranous, plicate, erect, slightly incurved over limen and nectary, the margin minutely fimbriate/ long-papillose, white; limen floor (tissue between limen edge and base of androgynophore) yellowish green, the edge only slightly raised, 2.8–3.3 mm diam., yellow nectary present but raised nectar ring (annulus) absent; androgynophore (3.5–)3.9– 4.2 x 1.0– 1.5 mm, tinged reddish purple near and below middle but yellow-green at base; stamens with filaments (free portions) (2.5–) 4–5 mm long, greenish, unmarked, anthers ca. 1.7–2.0 × 1 mm, greenish, unmarked; ovary ca. (1.5–)3 × (1–) 1.5–1.8 mm, ellipsoid, green, densely white pilose to hispid with white antrorse straight trichomes (2–)2.5(–3) mm long; styles (4–) 5–5.5 mm long including capitate stigmas, glabrous, greenish or with trace of reddish purple distally; stigmas 1.3–1.5 mm diam. Fruit a berry 26 mm long (including a 3–4 mm long stipe) × 13 mm, ellipsoid, acutely tapered at proximal end and with a short conical stipe, conical at apex, lightly pilose, nearly mature fruit yellowish green; seeds 4.0–4.4 × 2.5–2.8 mm, 1.3–1.4 mm thick, obovate, ca. symmetric around long axis, dark brown to nearly black, transversely sulcate with 7 to 8 sulci, the ca. 8 ridges rugulose, micropylar end acute, chalazal end ca. 90°, with a slight antiraphal crest or ridge ca. 0.2 mm wide, number of seeds per fruit ca. 21–25 (n=1).

Distribution and habitat:— Known only from three locations in the Districts of Huarango and San José de Lourdes, San Ignacio Province, Department of Cajamarca in northern Peru, at the southern end of the Cordillera del Cóndor. The species was found in primary cloud forest at 1500–2000 m. Around Cerro Parcos mountain in the District of San José de Lourdes, Esquerre-Ibañez observed at least 12 individuals.The soil there was described as “muddy clayey dark soil, typical of the understory, full of leaf litter…” and the plants were associated with ferns, mushrooms, Axinaea, Monochaetum, Cavendishia, Condaminea, Gurania , Bromeliaceae , epiphytic orchids (especially Pleurothallidinae), Heliconia , Araceae , Gesneriaceae , Piper , and Peperomia .

Conservation status:— With an extent of occurrence (EOO) of ca. 200 km 2 and an area of occupancy (AOO) surely much less than that, and only three known localities, Passiflora nana can be assigned the conservation status of Vulnerable (VU) according to criteria B1a,b and B2a,b of the IUCN (2013).

Etymology:— From Latin nanus, dwarf, referring to the dwarf stature of the plant and the very small flower.

Discussion:— Passiflora nana is notable for its small stature, small flowers, very conspicuous vestiture, and the reduction of the number of floral bracts to two or even one in some specimens. It is placed in subgenus Decaloba on the basis of its plicate operculum, and in supersection Decaloba ( de Candolle 1822: 435) J. M. MacDougal & Feuillet (2003: 37) section Decaloba on the basis of its grooved seeds, entire-margined leaves, non-marginal laminar nectaries, and cernuous shoot tip. The proportions and color of the parts of the flower suggests that the species is insect-pollinated ( Ocampo & Coppens d’Eeckenbrugge 2017). This small pilose species is not likely to be confused with any other Passiflora even when sterile. Passiflora hirtiflora from Ecuador is somewhat similar in its vestiture, but that species has larger flowers and foliaceous bracts, and a leaf with a much narrower lobe angle and more laminar nectaries. The flower greatly resembles that of P. erythrophylla of Colombia, especially in its small size, coloration, and orientation of the operculum and limen, but that species differs by having petals at least 2/3 the length of the sepals, not less than ½; an inner corona that well exceeds the length of the operculum, not subequal to it; and a glabrous, not long-pilose ovary. Furthermore, the plant body of P. erythrophylla is glabrescent to only microscopically sparsely puberulous, not covered in long white trichomes. The leaves of P. nana resemble those of P. pusilla J. M. MacDougal (1988: 392) of section Xerogona ( Rafinesque 1836: 103) Killip (1938: 26) from Mesoamerica, but that species has no laminar nectaries, a triangular stem, and a long-fusiform dehiscent fruit.

In the type material and in Vásquez et al. 20176 each peduncle has only one or two bracts, but Esquerre’s collections have peduncles with two or three bracts (see Figure 2F View FIGURE 2 ). This is the first report of a reduction in the number of bracts in section Decaloba s. str., which normally has three bracts (or bracteoles) on each peduncle.(Section Decaloba in the sense of clade W in Krosnick et al. (2013), roughly corresponding to Killip’s (1938: 39) invalidly published series “Punctatae.”). Generally, in the floral measurements above, the low ends of ranges represent dried material, and the high ends are from living material.

Fruits are known only from two examples from mid-June to mid-July, both yellowish green with a mix of fully mature and nearly mature seeds (near black vs. brown). Because the seeds in Passiflora mature before the fruit is fully ripe ( MacDougal 1989: 1174), the color of the fruit is not firmly established as yellowish green; nearly all other species in section Decaloba have fruits dark purplish at maturity, and additional observations are needed.

Additional specimens examined (paratypes):— PERU. CAJAMARCA: San Ignacio Province, Distrito San José de Lourdes, Santo Tomas , 04°55’S, 78°50’W, 2000 m, 15 Junio 1995 (bud, fr), R. Vásquez, C. Diaz, & A. Torres 20176 ( MO 6147707 [bc] MO-1183894) GoogleMaps ; Distrito San José de Lourdes, caserío Nuevo Villa Rica, Cerro Parcos , 05°4.26’S, 78°53.177’W, 1772 m, 2 Abril 2017, B. Esquerre 186 ( HUT) GoogleMaps ; 05°04.098’S, 78°53.019’W, 1810 m, 2 Abril 2017, B. Esquerre 187 ( HUT) GoogleMaps ; 05°04.241’S, 78°53.213’W, 1847 m, 2 Abril 2017, B. Esquerre 188 ( HUT) GoogleMaps .

Additional specimens examined:— Passiflora erythrophylla . COLOMBIA. Rio Magdalena, Goudot s.n. [2], (holotype: K [bc] K000323359 image!, photo at NY!; isotype: P). CUNDINAMARCA: Mpio. Caqueza, vereda El Charco , 1800 m, M. Arévalo et al. 23 (COL-429544 image!). Salto de Tequendama , 2500 m. J. Cuatrecasas 92 (COL-08180 image!, F [bc] 1327603!). Between Caqueza and Río Saname , 1600 m, F. Pennell 1329 (NY!). San Fortunato, 2500 m, Triana 2951 [5098] [TYPE of Passiflora erubescens Triana & Planchon (1873: 161) ], (BM, COL-08179 image!, P [bc] P00605734 image!). — Passiflora hirtiflora . ECUADOR. NAPO: Canton Archidona. Carretera Hollín-Loreto, km 25, Sector Challua Yacu, faldas al sur del Volcán Sumaco, 1200 m, Cerón & Hurtado 6426 (AAU, BM, HUA!, JAUM!, L, MO!, QCNE!, US!). Archidona–Loreto road, within a few km of Río Challua, 1060 m, MacDougal 4905 (MO!).