Anthurium mateoi
Terrestrial, scandent; internodes 4-12 cm long, 0.4 cm diam.; cataphylls persisting as scant fibers 2-4 cm. LEAVES 18.6 cm long with slender, weakly sulcate petioles 11-12 cm long, 2 mm diam., C-shaped, drying dark brown; geniculum 1 cm long, faint transverse creases visible microscopically; blades broadly ovate, subcordate, 17-18 cm long, 8 cm wide, 2.1 times longer than broad, 1.5 times longer than petiole, broadest at middle, cuspidate apex, epunctate on upper and lower surfaces, drying grey-green, semi-glossy on upper surface and yellow-brown, matte on lower surface; midvein drying acute and inconspicuous on upper surface, broadly rounded, finely ribbed and darker brown on lower surface; basal veins 2 pairs forming collective veins, the 1st pair free to the base, inconspicuous, running 1-2 mm from margin ending in the lower 1/4, 2ndpair more prominent, loop connecting to primary lateral veins, running 5 mm from margin to the apex; primary lateral veins 8 pairs, departing the midrib at 50°-60° angle, dry weakly raised, sometimes inconspicuous on upper surface, concolorous on lower surface and finely raised, slightly rounded and more prominent on the lower surface; tertiary veins twisted, irregular, inconspicuous. INFLORESCENCES 39.3 cm long with peduncle 35.2 cm long, 3 mm diam., drying dark brown, stipe 5.3 cm long, 2 mm diam.; spathe 4.2 cm long, 2.1 cm wide, spreading at 90° angle from peduncle, clear green, ovate, drying yellow-brown, spadix 4.3 cm long, 3 mm diam., cylindroid, dark purple-violet, drying very dark brown, 4 flowers visible per spiral, 3.4 mm long by 1.8 mm wide, lateral tepals 1.2-1.5 mm long, surface minutely granular, outer margins 2-sided, inner margins broadly rounded, often curved upward at center.
Anthurium mateoi is related to A. monteagudoi Croat and A. valenzuelae Croat, both included in this study, as all three species are members of the Xialophyllium. The latter two species differ by having much more elongated blades whereas A. mateoi has ovate blades 17-18 cm long. In the Lucid Anthurium key, A. mateoi tracks with A. geniculatum Sodiro and A. karstenianum Engl. Anthurium geniculatum is found in Ecuador, has long strap-like blades, is cuneate at the base and has many fine primary lateral veins. Anthurium karstenianum is also found in Ecuador and differs from A. mateoi in having oblong blades, arcuate at the base with the petiole weakly decurrent, 4 basal veins and only 6-8 primary lateral veins.
Anthurium mateoi is endemic to Peru, known only from the type locality in Pasco Department, Oxapampa Province in the Parque Nacional Yanachaga-Chemillen at 2,600 m in a Montane wet forest life zone (Holdridge et al., 1971).