Philodendron callosum K.Krause

Stem abbreviated. LEAVES: Petiole robust, somewhat flattened on the upper surface, and rather deeply canaliculated, 28-35 cm long, 1.5-2 cm thick at the base, somewhat attenuating upwards, the lower ? or 1/4 narrowly sheathed; Blade rigid, thickly coriaceous, rather glossy above, lanceolate or oblong-lanceolate, apex shortly oblique, cuspidate-acuminate, gradually narrowing towards the base, the extreme base somewhat obtuse, 30-50 cm long, 12-16 cm wide. Lateral veins all subequal, very numerous and very dense, departing the midrib (which is 6-9 mm wide, narrowing upwards) at an obtuse or very obtuse angle, arcuate-ascending towards the margin, distinctly prominent on both sides. INFLORESCENCE: Peduncle terete, moderately robust, 8-10 cm long, 8 mm thick. Spathe externally white or green towards the base, internally pale purplish, tube broadly ovoid, 3.5 cm long and almost equal-sided, blade ovate-oblong, apex shortly apiculate, 4.5-5 cm long, 4 cm wide. Spadix subtended by a 6-8 mm long stipe, female zone cylindric, 1.5-2 cm long, 1 cm thick, male zone claviform, apex obtuse, 5-6 cm long, equally thick as the lower, female zone or somewhat thicker, narrowing upwards. Pistil ovoid-oblong, stigma small round-raised, ca. 2 mm long, 1.5 mm thick, many locules [Mayo observed 2 locules], locules with few ovules. Male flowers 2-4 androus.