Passiflora Supersect. Cieca (Medic.) J. M. MacDougal & Feuillet. Passiflora 13(2): 37. 2003 [2004]. Basionym: Cieca Medic. Malvenfam. 97. 1787.

A selection of flowers from supersection Cieca, all presumed to be pollinated by small insects except P. viridiflora, which is pollinated by hummingbirds. Photo: J.M. MacDougal

A selection of insect-pollinated flowers from species of supersection Cieca showing absence of petals and variation in corona. Photo: J.M. MacDougal

The strange flower of Passiflora xiikzodz subsp. itzensis has no floral nectary, the ovary is basically sessile, and pollen is presented upwards. The pollinator is unknown. Photo: J.M. MacDougal

Passiflora juliana, sister to the long-tubed species P. viridiflora, inhabits coastal southwestern Mexico. Photo: J.M. MacDougal

Small to medium-sized climbing or procumbent vines with annual or perennial stems from woody perennial rootstocks or taproots, antrorsely appressed puberulent more or less throughout, with unicellular, curved or occasionally erect trichomes, and sometimes sparsely to densely pubescent with longer unicellular, rarely multicellular, curved trichomes. Stems terete to somewhat compressed and two-edged, the shoot apex erect. Leaves simple, commonly bearing nectaries on the petiole (except in P. eglandulosa and P. mcvaughiana); petioles sometimes canaliculate, biglandular (rarely eglandular or with only a single gland) with opposite, subopposite or alternate, discoid, cupulate, obconical or capitate extrafloral nectaries; laminas unlobed or 2- to 3-lobed (rarely 5-lobed), often exhibiting heterophylly, sometimes cordate at base, entire (very rarely crenate), venation pinnate or usually palmate, variegated or not, peltate or not, sometimes bearing small abaxial disciform or crateriform nectaries present ± submarginally between the major veins (very rarely associated with leaf crenations). Stipules setaceous to foliaceous, persistent, narrowly to widely ovate, rarely oblong or obovate, symmetrical or sometimes asymmetrical, entire, not glandular. Tendrils simple, lacking adhesive disks, straight or slightly curved during development at shoot apex. Inflorescences sessile in leaf axils, the pedicels solitary or paired, collateral with tendril, articulate, the articulation generally several mm below the flower; secondary inflorescences sometimes present as condensed axillary or usually terminal shoots, determinate or usually indeterminate; bracts 1 or 2 or lacking, narrowly ovate to entire. Flowers erect or rarely ± horizontal, greenish yellow sometimes with purplish to reddish markings, or red, hypanthium usually shallow, occasionally the calyx basally connate into a conspicuous floral tube; sepals ovate-triangular, not corniculate, greenish yellow or red; petals absent; coronal filaments in 2 series (rarely 1 or 7 series), greenish yellow, sometimes with yellow and/or purple to red markings, or purple to red, linear, often subcylindrical in cross-section, inner filaments usually capitate; operculum connate, membranous, plicate (very rarely denticulate), incurved or rarely semierect and laying against androgynophore; nectary trough-shaped or rarely absent, commonly lacking a low annular ridge (nectar ring); limen adnate to floor of hypanthium or rarely absent (in P. viridiflora the limen present as a shallow cup around base of androgynophore), recurved or sometimes erect to inclined toward operculum. Staminal filaments with the free portions actinomorphic; anthers extrorse at anthesis with their axes maintained parallel to the filament or rarely only moving slightly from the original introrse position to dehisce distally (upwards); pollen ellipsoid to spherical, 6-syncolporate. Ovary ellipsoid or globose, rarely slightly ovoid, obovoid or fusiform, glabrous or rarely densely pubescent with curved, unicellular or rarely multicellular trichomes; styles slender, less than 1.5 mm in diameter; stigmas capitate, depressed-ovoid. Fruit a few to many-seeded purple or very dark purple berry, arils pale-translucent covering approximately 3/4 of the seed. Seeds more or less compressed, often beaked at chalazal apex, reticulate-foveate. Germination epigeal. Chromosome numbers: n=6 (12, 18). Commonly lacking C-glycosylflavones and usually containing flavonol 3-O-glycosides.

Supersection Cieca is a monophyletic group of herbaceous to woody climbers found in subtropical and tropical regions of the world from latitude 34°N to latitude 34°S. The 19 species recognized here (three still undescribed) are primarily distributed in the southern United States, Mexico, Central America, South America, and the Caribbean. Two species, P. suberosa L. and P. pallida L., also occur in various regions of the Old World, likely as a result of naturalization.

Supersection Cieca belongs within subgenus Decaloba on the basis of having flowers with the corona in a few series, a plicate operculum, secondary opercula on the pollen grains, and a base chromosome number of six. The species of the supersection are easily recognized by their small, apetalous, usually greenish flowers with the filaments of the corona mostly in two series. Several factors enhance the biological significance of Passiflora supersection Cieca. Of the four pollination syndromes commonly reported for Passiflora, supersection Cieca exhibits three: melittophily (pollination by bees), sphecophily (pollination by wasps), and ornithophily (pollination by birds). The species of the supersection are also utilized as larval hosts by both primitive and advanced genera of the subfamily Heliconiinae (Agraulis, Dione, Dryandula, Dryas, Euptoieta, Heliconius, and Philaethria). Four of the 16 named species are listed as endangered or threatened in the 1997 IUCN Red List of Threatened Plants. One species, P. clypeophylla Mast., may be extinct and is represented by only a single herbarium specimen. The status of another species, P. macfadyenii C.D. Adams, is uncertain, because it has not been found in its native habitat in Jamaica since 1998.