Araceae
Anthurium riograndicola Matuda
SUMMARY
Terrestrial; stems 2 cm diam. or larger; cataphylls triangular, drying reddish-brown, weathering into moderately thin longitudinal fibers. LEAVES with petioles to 50 cm long, 7-9 mm diam., bluntly sulcate adaxially; geniculum 1.5 cm long, thicker than petiole, obtusely and narrowly sulcate; blades coriaceous, narrowly ovate, acute at apex with short apiculum, deeply lobed at base, to 35 cm long, 22.5 cm wide, broadest just below point of attachment; the anterior lobe 25.5 cm long; the posterior lobes 12.5 cm long from apex of sinus to tip of lobe; sinus obovate, rounded at apex; upper surface semiglossy, with sparse glandular punctuation's, lower surface semiglossy with dense glandular punctations (the punctae irregular, to 0.4 mm diam.); the midrib prominently raised above, diminished and sunken at apex, sharply raised below; basal veins 5-6(7) pairs, the 4-5(6)th coalesced ca. 3.5 cm; posterior ribs slightly curved, the outer margin curled up and inward; the primary lateral veins 4-5 per side, scarcely visible, departing midrib at 50° angle, curved to the collective vein, raised below, interprimary veins scarcely less prominent than primary lateral veins; collective vein arising from one of the basal veins, 2-10 mm from margin. INFLORESCENCE erect-spreading (?); peduncle to 69 cm long, 7 mm diam., terete, longer than petioles; spathe subcoriaceous, green tinged with purple, oblong-lanceolate, to 11.5 cm long, to 1.2 cm wide, broadest just above the base, meeting on peduncle at ca. 90° angle; spadix sessile, to 17.5 cm long, to 1 cm diam. at base, to 4 mm diam. At apex; flowers rhombic, 3.7-4 mm long (dry), 2.7-3 mm wide (dry), the sides straight to sigmoid; 8-10 flowers visible in the principal spiral, 6-7 flowers visible in the alternate spiral; lateral tepals ca. 2 mm wide (dry), the inner margins concave; pistils weakly emergent; the stigma ellipsoid, 1 mm long; stamens exserted just above edge of tepals; anthers held at edges of pistil, 0.5 mm long (dry), 0.7 mm wide; thecae broadly elliptic, scarcely divaricate; pollen not seen. INFRUCTESCENCE not seen.