Passiflora lorenziana Mezzonato & Bernacci, 2016

Mezzonato-Pires, Ana Carolina, Gonçalves-Esteves, Vania & Bernacci, Luís Carlos, 2016, A new species of Passiflora subgenus Astrophea (Passifloraceae) from the Brazilian Amazon, Phytotaxa 288 (1), pp. 77-84 : 78-83

Passiflora lorenziana Mezzonato & Bernacci , sp. nov. ( Fig. 1 )

Type: BRAZIL. Amazonas: São Gabriel da Cachoeira, estrada para Cucuí , km 32, em beira de mata, 94 m, 00º01’02.3”N, 66º53’52.3”W, 03 July 2002, H. Lorenzi 3330 (holotype, HPL!) .

New species (section Pseudoastrophea ), with widely elliptical to widely ovate leaf blade, cylindrical-campanulate hypanthium, resembling P. mansoi (Mart.) Mast (1871: 629) from which it is distinguished by auriculiform enlargement at the base of the leaf blade, corona with 4 well-defined series of filaments, more numerous undefined series, and discoidal-undulating trochlea.

Woody liana with tendrils slender, spines absent ( Fig. 2a ). Branches 3.92 mm wide, cylindrical, striated, yellowishbrown, slightly puberulous. Stipules not seen. Petiole 17.49–19.04 × 1.11–1.30 mm, slightly puberulous; two glands 1.26–1.66 × 0.78–0.95 mm, elliptical-obovate, margin yellow, center dark, abaxial, in an auriculiform enlargement, 2.38–2.96 × 1.38–2.45 mm, at blade base. Leaf blade 9.51–11.80 × 7.40–9.50 cm, broadly elliptical to broadly ovate, cartaceous-membranous, apex attenuated, base rounded to slightly cordate, glabrous; with many glands, 0.66–0.73 × 0.32–0.41 mm, throughout margin; 8–12 veins, arched. Peduncle 6.50–7.67 mm. Bracts 1.30–1.38 × 0.80–1.11 mm, setaceous. Pedicel 5.93–6.54 mm. Flowers solitary, cylindrical-campanulate, hypanthium 5.02–7.57 mm wide, trichomes yellow; sepals 2.46 × 0.66 cm, abaxial green, adaxial white, glabrous, apex rounded, linear-oblong; petals sub-equal, white, glabrous, apex rounded, linear-oblong. Corona with four well-defined series of filaments, more numerous undefined series, insertion of corona up to 10.72 mm from base of hypanthium; filaments of first series 19.50 × 2.55 mm, linear, margin entire to half or two-thirds, thereafter densely verrucose and eventually bifurcated, yellow with vinaceous-brown blotches for entire length; filaments of the second series 1.70 × 0.62–0.68 mm, ligulate, apex slightly verrucose, yellow; filaments of the third series 1.50 × 0.19 mm, linear, yellow; filaments of the fourth series 0.08 × 0.33 mm, linear-tuberculate, yellow; filaments more interior linear or tuberculate, with margin slightly verrucose. Operculum 2.61–3.50 mm long, 3.98 mm from hypanthium base, filamentous up to or very close to point of insertion, apex clavate with irregularly cutting margin, nectariferous ring 0.89 mm from hypanthium base. Androgynophore 22.69 mm long, whitish, trochlea 0.38 × 2.50 mm, discoid undulate, vinaceous-brown to 10.83 mm from base, beyond which are whitish trichomes ( Fig. 2b ). Filaments 6.01 × 0.88 mm, glabrous, brownish. Anthers 6.52 × 2.92 mm. Ovary 4.85 × 3.10 mm, obovate, densely velutinous, trichomes yellow. Style 4.98 × 0.84 mm velutinous, base greenish, apex mottled brown. Fruit not seen.

Palynology

Pollen grains medium-sized, polar diameter 42.5–47.5 μm, equatorial diameter 35.0–40.0 μm ( Fig. 2c ); shape subprolate; polar area small, 0.45 μm; amb subcircular, 6-colporate, ectoaperture long, 31.2 μm long and 1.6 μm wide; endoaperture lalongate ( Fig. 2d ) 8.4 μm long and 13.2 wide. (one pollen grain had two endoapertures, 8 μm long and 3–5 μm wide); pontoperculum 10.8 μm wide, the pontopercula decrease in width in the apocolpium ( Fig. 2e, 2f ); sexine reticulate, heterobrochate, walls 1.2 μm wide, simplicolumellate, straight, without high collumellae, not apparent, ceiling with the most superficial part curved, lumina 3.1 μm in diameter, not ornamented ( Fig. 2g ). No difference in diameter of lumina of apocolpium and mesocolpium. Sexine (1.9 μm) thicker than nexine (1.3 μm).

Distribution and Habitat

This new species is known only from the type locality of São Gabriel da Cachoeira in the state of Amazonas. It occurs near the edge of a forest at 94 m elevation.

Phenology

Collected in flower in the month of July.

Etymology

The name of the species is a tribute to the botanist and specimen collector Harri Lorenzi.

Features and affinities

Passiflora lorenziana is inserted in the section Pseudoastrophea (Harms) Killip (1938: 31) for being a shrub or woody liana with peduncles solitary or paired, simple and short, hypanthium campanulate, cylindrical-campanulate or tapered, smaller than the sepals, and corona not plumose. It is easily recognized by its widely elliptical or ovate leaf blades, with auriculiform enlargement at the base where two glands are located on the abaxial surface, and its corona with four well-defined series of filaments, followed by numerous irregular series in addition to discoidal, undulating trochlea ( Table 1 ).

Passiflora lorenziana exhibits leaf morphology similar to that of P. mansoi Mast. and P. rhamnifolia Mast. (1872: 575) , which have broad leaf blades. However, the two glands present in P. lorenziana are the most differentiated, being positioned on the abaxial surface, in an extension on the base of the leaf blade, which easily distinguishes it from other species of the subgenus Astrophea . Although, P. phaeocaula Killip (1927: 430) also has glands on the abaxial surface, these are located in a narrow extension of the leaf blade, resulting in the petiole, and not in an auriculiform enlargement confined to the base of the leaf blade as in P. lorenziana ( Table 1 ).

Among the species most similar to P. lorenziana ( Table 1 ), only P. mansoi possesses a cylindrical-campanulate hypanthium, while P. rhamnifolia possesses trochlea. However, the trochlea of P. lorenziana is discoidal-undulate and not fusiform as in P. rhamnifolia . The new species and P. candida (Poeppig & Endlicher) Masters (1871: 629) , both posses a corona with numerous irregular series of filaments., but they differ in that the most external filaments of P. lorenziana are linear, while those of P. candida are liguliform, although they are verrucose on the margin to the apex in both cases. The coloration of the corona also differs between these two species, being yellow with large brownish-wine colored blotches in P. lorenziana and yellow speckled with red in P. candida . Lastly, the hypanthium is funnel-shaped in P. candida and cylindrical-campanulate in P. lorenziana .

The pollen grains of P. lorenziana are of pollen type IV, among the five described by Mezzonato-Pires et al. (2016, no press). Type IV pollen is characterized by having a semitectate exine; presence of continuous walls; sexine simplicolumellate; small lumina (0.8–8.6 μm) and the presence or absence of bacula, and is shared with P. mansoi , P. phaeocaula and P. rhamnifolia . Among the most similar species to P. lorenziana compared here, only P. candida has pollen grains of type III, which are characterized by semitectate exine, presence of continuous or discontinuous walls; sexine simpli or duplicolumellate; large lumina (11.3–24.5 μm) and the presence of pila and/or bacula.

Passiflora chlorina L.K. Escobar (1989: 132) was the last species of subgenus Astrophea described in Brazil, and so P. lorenziana is the first species of this group to be described in 27 years.

Despite occurring next to a road and not within a Conservation Unit, the region where the species was collected is surrounded by five Indigenous Lands and is a few kilometers from the Parque Nacional do Pico da Neblina. Thus, P. lorenziana was considered by the Centro Nacional de Conservação da Flora-National Center for Plant Conservation (2016), as belonging in the category Least Concerned (LC), based on the criteria of the IUCN (International Union for Conservation of Nature).

Figures

FIGURE 1. Passiflora lorenziana sp. nov. (A) habit, (B) leaf, (C) glands, (D) flowers, (E) outer filaments, (F) inner filaments, (G) operculum, (H) apex detail operculum, (I) trochlea. Illustrated by Monique Goes.

FIGURE 2. Morphology and palynology of Passiflora lorenziana. (A) Branch detail, (B) flower detail, arrow indicates the trochlea, (C) pollen grains in polar view, general aspect (SEM), (D) pollen grains in equatorial view, optical section, arrow indicates endoaperture (LM), (E) pollen grains in equatorial view, apertures detail, arrow indicates pontoperculum (SEM), (F) pollen grains in equatorial view, mesocolpium (SEM), (G) ornamentation detail (SEM). Scale bar: A. 2 mm, B. 10 mm, C–F. 10 μm, G. 2 μm. SEM = scanning electron microscopy, LM= Light microscopy. (Photos A and B by H. Lorenzi; C, D, E, F, G by A.C. Mezzonato.)