Passiflora gigantifolia Harms, 1894

Kuethe, J. R., Cornejo, Xavier, Garzón-Suárez, Henry X., Jiménez, Marco M., Wettges, Martin, Magdalena, Carlos, Mejía-Pazos, Nicanor, Flores, Juan Carlos Espín & Decoux, Jose, 2025, Passionflower trees of Ecuador: revising the presence of Passiflora subg. Astrophea (Passifloraceae) and including resolution to the P. putumayensis and P. macrophylla taxonomic complexes, Phytotaxa 697 (2), pp. 147-165 : 155

3. Passiflora gigantifolia Harms in Engler & Prantl (1893: 88) ( Figure 3b,d,f )

Type:— ECUADOR. Bolívar : Babahoyo municipality,near Pisagua and Balsabamba, 01°04’S 79°14’W, 550 m, October 1888 (fl.), Lehmann 4837 (holotype: B, destroyed; lectotype: K 00323442 !, designated here; isolectotype: F 0077873 !; photo: F ( B) F 0 BN016531 !) .

Description:—Large wooded and scandent shrub, sparingly branched, 1.5 to 4 meters high, without tendrils, glabrous to glabrescent throughout, except for the ovary. Stems and branchlets subterete to terete, wooded. Stipules absent or very soon deciduous, when present triangular, scale-like, 1 mm, green, coriaceous. Petioles 3–7 cm long, very sturdy, glaucous to glabrescent; with a single pair of scarlike glands positioned at the base of the blade. Leaves enormous, oblong-obovate or oblong, 70–170 cm long, 30–70 cm wide, sharply acuminate at apex, rounded to cordulate at base, penninerved, texture membranous when young, becoming thick coriaceous when mature, glabrous on both sides, a deep green above, glaucous beneath. Inflorescence axillary, pendent, bearing a single peduncle with multiple branching pedicels totalling up to 12 flowers per node. Peduncles twice dichotomous, pendent, the common peduncle up to 15 cm long, the bifurcated part up to 5–7 cm long. Flowers pendent, greenish-white with pale yellow corona, 8–10 cm wide measured from tip to tip, weakly scented; hypanthium cylindric, 5–6 cm long, 7–10 mm in diameter when measured at midsection, base distinctly globose, rounded, stretching to about 15–16 mm wide, greenish white on the outside, green within; sepals linear to linear-oblong, 3.2–4.5 cm long, 7–9 mm wide, obtuse to rounded at apex, slightly concave, ecorniculate, subcoriaceous, greenish without, greenish-white within, fleshy; petals subequal to the sepals, 3.0– 4.4 cm long, 7–8 mm wide, slightly more membranous, whitish green; corona filaments in two series, very pale yellow to greenish yellow, erect and outfacing throughout; the outer series conspicuous, 2.5–3.3 cm long, slightly widened towards the apex, flattened in cross-section, straight, pale yellow becoming whitish towards the base; the inner series tuberculate to very shortly filamentose, 0.8–1 mm long, falciform, erect, darker yellow with a green base; operculum borne just above the base of the swelling, membranous, erect, laciniate to below the middle, cleft upwards surrounding the base of the androgynophore, white with a yellow tip; limen cupuliform, white; nectar chamber slightly chambered into 5–6 segments, yellowish-white; androgynophore stout, green, 6 cm long; ovary white-tomentose, ellipsoid. Fruit oblong-obovate to pyriform, green when mature with a sturdy pericarp, mesocarp whitish grey.

Distribution:—Unlike its dry-coastal counterpart, Passiflora gigantifolia was found in wet premontane cloud forests at elevations between 800 and 1600 m. Its distribution appears to be restricted to the west-facing Andean foothills of El Oro and Los Ríos Provinces, Ecuador, with noticeable populations seen in the Buenaventura and Jocotoco reserves north-west of Cisna and due east from Machala. The treelets are seen growing as a partial understory shrub, where it appears to prefer steep slopes under a broken canopy that permits partial sunlight to penetrate through. Additionally, it was observed that the large umbrifellous foliage acts as a “parasol” to protect the flowers from direct sunlight or harsh rain fall. This foliar habit could also aid to regulate a moister temperature for an optimal floral physiological work.

Conservation status:—Three field-verified populations of Passiflora gigantifolia were examined during the 2022 expedition, and two additional populations verified from georeferenced material (field photographs) to calculate an EOO and AOO measure of 10,840 km 2 and 62 km 2, respectively. This classifies this species as VU-EN (Vulnerable to Endangered) in accordance with the geographical criteria, B2ci,ii,v, C2aii,b and D.

Notes:—For long, Passiflora gigantifolia was considered a synonym for P. macrophylla , two species known for their low scandent habit with disproportionately large leaves ( Holm-Nielsen et al. 1988, Ulmer & MacDougal 2004, Hilgenhof 2013, 2017). However, their origin and subsequent treatment has remained separate for some time. Originally described by Hermann Harms in the Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 18 (pp. 46): 1. 1894, the material collected by F.C. Lehmann was from near Pisagua in the sub- Andean province of Bolívar, Ecuador. In 1938, monographer Elsworth Killip maintained P. gigantifolia based on the elongated hypanthium with a globular base and its lesser corona series ( Killip 1938), though the distinction of his noted diagnostic traits weren’t always as clear. In 1988, Holm-Nielsen et al. synonymized P. gigantifolia for P. macrophylla based on their similarity in scandent habit with gigantean leaves, extending the habitat for P. macrophylla further south and up several stratigraphic levels of elevation opposed to the otherwise exclusively lowland (and coastal) P. macrophylla .

In 2012, Rich Hoyer took photographs of a “ Passiflora macrophylla ” from the Jocotoco reserve in Andean Ecuador, exhibiting a rather unusual floral orientation where the flower corollas, bearing a corona of a pale yellow in colour, were distinctly pendent opposed to the otherwise subhorizontal to horizontal orientation the corolla of P. macrophylla was well-known for. In addition, the corona appeared straight throughout instead of diagnostically undulate and lacked the warm yellow-orange colour consistently seen in accessions of P. macrophylla . The long hypanthium, with its distinctly globose calyx base, further matched Killip’s 1938 descriptions for his P. gigantifolia , suggesting valid circumscription of both species as separate taxa. This hunch was solidified following additional collections of both P. macrophylla and P. gigantifolia by the authorial team over December 2022, assessing material collected from Esmeraldas (coastal Ecuador) and Buenaventura reserve (Andean-cloud forest, southwestern Ecuador) in the El Oro and Bolívar provinces. Other differences include the size of the flower (8–10 cm), which is substantially larger than the relatively small (5–6 cm) flowers of P. macrophylla ; the length and structure of the inner corona (one additional series of 1 mm long vs. 2 additional series of 3–4 mm long); the orientation of the inflorescence (pendent vs. upright); and fruit (pyriform with sturdy [glabrous] pericarp vs. ellipsoid with a glabrescent pericarp). Vegetatively the two species are much similar, though the foliar texture (coriaceous vs. chartaceous) and apices (sharply acuminate vs. rounded to emarginate) bear additional differences for identification.

Figures

FIGURE 3. Direct comparison between Passiflora macrophylla (A,C,D) and the newly restored P. gigantifolia (B,D,F). Detailing the upright vs. pendent inflorescence (A,B); the longitudinal with the difference in hypanthium (C,D); and the flower structure (E,F). All photos taken by J.R. Kuethe.