Plants mostly epiphytic. Old stems woody at base, often terete; branches usually flattened and leaflike, or 3-winged, with stout midrib, margins crenate, coarsely serrate, or lacerate, sometimes horny. Areoles seated between crenations of stem margins, woolly when young, setose in juvenile growth. Leaves and spines absent. Flowers nocturnal, borne in lateral areoles, solitary, sessile, funnelform or salverform, usually large. Receptacle tube elongate, with scattered scales. Perianth spreading to rotate; segments usually linear-lanceolate. Petaloids white; outer ones often recurved, sometimes cream or pinkish. Stamens numerous; filaments inserted in receptacle tube and perianth throat; anthers exserted. Placentas parietal; style elongate; stigmas numerous, exserted, linear. Fruit green, red, or purplish, globose to cylindric, usually fleshy, with low ridges bearing scales, usually splitting along one side when ripe. Seeds numerous, ovate-reniform; testa glossy black, minutely wrinkled or spotted.
Arbustos epífitos o bejucos, tallos colgantes a erectos o escandentes, leñosos en la base, las partes superiores aplanadas, con márgenes undulados, crenados o lobados; aréolas desnudas o con tricomas y cerdas en los brotes juveniles. Hojas como escamas diminutas. Flores grandes, nocturnas o raramente diurnas; tubo receptacular alargado, con escamas; partes del perianto patentes o rotáceas, mayormente blancas. Frutos globosos u oblongos, carnosos, frecuentemente separándose a lo largo de un lado, rojos exponiendo una pulpa blanca con negro; semillas lustrosas.
Género con ca 15 especies distribuidas desde México hasta Argentina y Paraguay, la mayoría en Centroamérica; 3 especies se conocen en Nicaragua.
Shrubs, epiphytic or rarely epipetric, erect to pendent, many branched. Roots diffuse or adventitious along stems. Stems segmented, green, segments leaflike, narrowly elongate-oblanceolate, terete or 3-angled in narrow proximal portion, broadly flattened and bladelike distally, with prominent midvein-like axis, [30-]50-120+[-500] × [1.5-]4-5[-12+] cm, glabrous; ribs 2 or, on proximal portion and on juvenile stems, 3, rib margins (crests) crenate-undulate to shallow lobed [serrate to pinnatifid in other species]; areoles only in sinuses along rib margins (ca. 2-7 cm apart along rib), circular, woolly, stiff spines absent, sometimes fine, hairlike bristles present; areolar glands absent; cortex and pith mucilaginous. Spines usually absent from adult stems, present and slender on terete and juvenile stems. Flowers nocturnal [diurnal in 2 species], lateral on stem in marginal areoles, with long tube, salverform to funnelform, 8-38 cm; flower tube straight or strongly curved to 90°; outer tepals greenish [to yellow, white, or dull red] often tinged with red, 3-10 cm, margins entire; inner tepals white [to yellow], 3-10 cm, margins entire; ovary scaly, spineless, spiny, or with bristles or hairlike spines; scales small; stigma lobes 8-21, white, extending beyond stamens, ca. 10 mm. Fruits dehiscent along 1 side when mature, light green, red, or purple, smooth [to ridged or angular], ellipsoid to ovoid, [20-]40-100 × 20-50 mm, fleshy, spineless, spiny, or with bristles or hairlike spines; pulp white or slightly pinkish; floral remnant persistent. Seeds black, reniform, 2-3 × 1-2.5 mm; testa cells shiny or dull when minutely pitted. x = 11.
Succulent shrubby plants, usually epiphytic root-climbers; stems phylloid and jointed, usually of two intergrading types: the primary terete or subterete, usu- ally rooting, the secondary (flowering) flattened and leaf-like, lobed or undulate, the areoles marginal, naked or rarely minutely puberulent. Leaves lacking. Flow- ers nocturnal or ephemeral, sessile, borne singly at the areoles; perianth usually large, infundibuliform, the segments very numerous, the outer progressively shorter and less petaloid than the inner, reflexed or spreading, the tube relatively slender, usually longer than the segments, bearing usually few and sparse, inconspicuous bracts, usually without definite areoles; stamens very numerous, the filaments somewhat shorter than the perianth and united at progressively deeper levels to the hypanthium; ovary frequently cylindric-ovoid, with few to numerous naked or rarely minutely puberulent areoles; style filiform, somewhat longer than the stamens. Fruit a fleshy berry with numerous seeds.
|Climbing cactus [Greek epi, upon, and phyllon, a leaf, referring to flowers borne on leaves, actually phylloclades, leaflike stems]|