Anthurium tysonii Croat

Usually terrestrial; stems 10 cm or more long, ca. 2 cm diam., leaf scars ca. 1 cm wide, mostly obscured by cataphylls; roots moderately thick, green, descending; cataphylls subcoriaceous, 15-24 cm long, acute at apex with minute subapical apiculum, drying brown (B & K. Yellow 4/5-4/7.5), persisting intact. LEAVES with petioles erect-spreading, 26-58 cm long, 5-7 mm diam., narrowly sulcate, the margins acute, sometimes several ribbed abaxially; geniculum 2-3 cm long; blades moderately thick, ovate, acuminate at apex, deeply lobed at base, (16-)28-49 cm long, (11-) 22-36 cm wide, broadest at point of petiole attachment or just above; anterior lobe (15-)23-34 cm long, the margins rounded, posterior lobes (4.2-)9-13 cm long, from apex of sinus to outermost point; sinus triangular to hippocrepiform, usually acute at apex; upper surface semiglossy with conspicuous round raphide cells; lower surface glossy; midrib acutely raised from base to middle, flat to weakly sunken toward apex above, acutely raised below; basal veins (3-)5-6 pairs, free to the base, sunken above, raised below, posterior rib absent; primary lateral veins 3-6 per side, departing midrib at 40-45° angle, sunken above, raised below, more or less straight to collective vein; interprimary veins weakly sunken above, obscure below; collective vein arising from the first or second basal vein, 3-5 mm from margin, sunken above, raised below. INFLORESCENCE erect, shorter than leaves; peduncle 10-24 cm long, 4-6 mm diam., one-half to one-third as long as petiole; spathe subcoriaceous, pale green, ovate to broadly lanceolate, 6-10 cm long, 2-4.5 cm wide, broadest near the base, long-acuminate to cuspidate at apex, rounded, more or less clasping at base; spadix pale green to creamy white, turning violet purple at anthesis, scarcely tapered at apex, (4.5-)6-10 cm long, 8-10 mm diam. near base, 6-8 mm diam. near apex; flowers rhombic, 1.7-1.9 mm long, 1.8-2.1 mm wide, the sides sigmoid, 6-9 flowers visible in the principal spiral, 11-15 flowers visible in the alternate spiral; lateral tepals ca. 1.1 mm wide, the inner margin convex; pistils scarcely emergent; stigmas linear; stamens emerging in a scattered manner, laterals usually emerging throughout before alternates emerge; anthers held at edge of tepals; thecae ovate. INFRUCTESCENCE erect; spathe usually reflexed; spadix 8-10 cm long, 2-2.3 cm diam.; immature berries rounded at apex, white to pale purple.