BLADES SIMPLE, NON-CORDATE, EITHER OBLONG OR OVATE; SUBCORDATE TO CORDULATE AT BASE.
1a. Plants vines or at least with internodes much longer than broad. If not
VINES OR SCANDENT: INTERNODES MUCH LONGER THAN BROAD; BLADES OVATE
4b. Blades less than 10 cm wide; peduncles less than 7 cm long.
more than 15 cm long; blades ca. 2 times longer than wide, drying brown,
with up to 2 obscure primary lateral veins; Costa Rica, Río Chirripó
del Pacífico, San José Prov., 1,000 m.
P. chirripoense Croat & Grayum
3b. Blades with the primary lateral veins more than 2 and each much more prominent than the minor veins.
petioles and inflorescences glabrous; major veins on lower surface glabrous;
Panama (Coclé, Veraguas), 770-1,200 m.
P. ligulatum var. ovatum Croat
6b. Blades narrowly ovate to oblong-elliptic, usually more than 2 times longer than wide.
9a. Blades lacking distinct primary veins at base of blade; primary lateral veins very obscure or lacking.
10a. Blades drying gray-green; primary lateral veins not at all apparent; Panama (San Blas), near sea level.9b. Blades with one or more distinct primary veins at base of blade; primary lateral veins distinct.
P. ubigantupense Croat
10b. Blades drying reddish brown or blackened; primary lateral veins 3-6, obscure but still visible.
11a. Blades drying blackened, usually more than 25 cm long; spathe green tinged dull red within; Panama (Bocas del Toro and Chiriquí), 780-1,400 m.
P. correae Croat
11b. Blades drying reddish brown, usually less than 25 cm long; spathe dark maroon or red within; Costa Rica (100-900 m) to Panama, 900-1,420 m.
P. bakeri Croat & Grayum
12a. Petioles encircled with a dark purplish (or dark green) ring at apex separating the petiole and the blade.13a. Blades with posterior lobes usually narrowly rounded and somewhat spreading or broader than long, rarely and about as long as broad; inflorescences 1-3 per axil; Panama, 100-970 m.
P. annulatum Croat
13b. Blades with posterior lobes about as broad as long and held closely near the petiole; inflorescence usually solitary, (sometimes 2 in P. immixtum).14a. Blades drying typically greenish to greenish brown; spathe tube red to violet-purple within at base; Panama to Colombia, 0-140 m.
P. immixtum Schott
14b. Blades drying typically blackened; spathe tube white within, tinged violet-purple near the base; Nicaragua to Colombia, 0-1,200 m.
P. ligulatum Schott, var. ligulatum
12a. Petioles lacking a dark purple ring at the apex.
1b. Plants appressed-climbing or sometimes terrestrial but with the internodes typically broader than long or only slightly longer than broad.15a. Blades less than 10 cm wide; stem minutely pale granular-puberulent at high magnification; pistil with a funnel-shaped stigma (type E); ovules 1 per locule; Panama (Darién), 75 m.
P. granulare Croat
15b. Blades usually more than 15 cm wide (rarely to as little as 10 cm wide in P. heleniae); stems smooth to irregularly ridged or folded at high magnification (sometimes minutely warty but not pale granular-puberulent); pistil with a flat style apex (type B); ovules 3 or more per locule.16a. Blades drying coriaceous, lacking secretory ducts; inflorescences greenish white to white outside, more than 12 cm long; Costa Rica to Panama, 670-1,800 m.
P. lentii Croat & Grayum
16b. Blades drying subcoriaceous, with conspicuous secretory ducts; inflorescences red, mostly less than 10 cm long; Panama and Ecuador, mostly 100-1,040 m.
P. heleniae Croat
17a. Cataphylls deciduous. If persistent
thick-drying; sinus oblong to parabolic or arcuate but with blade tissue
not at all decurrent onto petiole; Panama, 100-970 m.
P. annulatum Croat
20a. Largest leaf blades more than 50 cm long.
21b. Blades less than 30 cm wide; petioles typically much shorter than the blade.
22b. Blades drying dark gray-green to blackened, usually less than 4.3 times longer than wide; petiole with a purple or green ring at the apex.
sharply D-shaped with slender wings on the adaxial margins; Panama, Darién,
P. ligulatum var. heraclioanum Croat
24b. Blades drying yellow-brown or brownish, gray-brown to reddish brown, moderately coriaceous.
17b. Cataphylls persistent.
epiphytic to hemiepiphytic, not rosulate; petioles as thick as broad; blades
linear to oblanceolate or oblong-elliptic, sometimes weakly cordate to
cordulate at base.
oblong-elliptic to narrowly ovate, obtuse to subcordate at base; primary
lateral veins arising at 60-75E angle; cross-veins very conspicuous on
drying; sap not colored, or if so not white; Costa Rica to Colombia, 0-1,200
P. scalarinerve Croat & Grayum
subterete; blades narrowly cordulate at base, less than 1.8 times longer
than petioles; southwestern Costa Rica, Pacific lowlands, 0-1,200 m.
P. auriculatum Standl. & L.O. Williams