Epiphyte; stem elongate, ca. 1 cm diam.; roots thick; cataphylls persisting intact, overlapping at base, drying yellow-brown.

LEAVES spreading; petioles broadly sulcate, rounded to 3-ribbcd abaxially, 7-12 cm long, 6-7 mm diam.; blades narrowly oblanceolate, subcoriaceous, 40-80 cm long, 5-11.5 cm wide, narrowly attenuate at base, long-acuminate at apex; primary lateral veins 10-12 per side, raised above and below (dry), departing midrib at 40°-45° angle, weakly arched to collective vein; the collective vein arising from the base or one of the lowermost primary lateral veins, 1-4 mm from margin.

INFLORESCENCE shorter than leaves; peduncle 29-32 cm long; spathe lanceolate-ovate, green, 5-7.7 cm long, 2-2.6 cm wide, clasping at base; spadix creamy white, oblong to clavate, 4.5-6 cm long, 0.8-1 cm diam. at base, 9 mm diam. at apex; 10-12 flowers visible in the principal spiral; tepals matte, longer than wide; stamens exsertcd, emerging in a somewhat irregular fashion in a complete sequence, the leading stamens 1-2 spirals ahead of the third and fourth; pollen yellow, faintly aromatic at anthesis.

INFRUCTESCENCE with spadix to 13 cm long; 1.5-1.7 cm diam.; berries bright red, obovoid, ca. 4.6-7 mm long, 4-5 mm wide; seeds 2, 2.7-2.9 mm long, 1.5-1.7 mm wide. Figs. 67 and 68.

The species is found in Costa Rica in tropical wet forest formations from sea level to 800 m elevation. Until recently it was known only from the Osa Península and the adjacent Golfo Dulce region, but now it has been collected in San José Province on the road to Purrita.

Anthurium eximium can be distinguished by the oblanceolate, epunctate leaves, the persisting cataphylls, the clasping, lanceolate spathe, the cylindrical to clavate spadix, and the bright red berries. The species resembles A. spathiphyllum, which is restricted to the Atlantic slope, in spadix and leaf characters, but can be distinguished by the persisting cataphylls. In his monograph, Engler (1905) cited A. eximium as a synonym of A. consobrinum. The leaf shapes in both species are very similar. However, Schott's illustration of A. consobrinum clearly shows a long, slightly tapering spadix with pistils and berries greatly exceeding the tepals. Anthurium consobrinum is a common species of the Atlantic lowlands and numerous collections are consistent with Schott's drawing. The berries of A. consobrinum are white with purple, pink or orange apices as opposed to the solid bright red berries of A. eximium. In addition, the pistils of A. consobrinum are early long-exserted and are held at about the level of the stamens at anthesis. Anthurium eximium is a member of section Pachyneurium despite certain features it shares with section Calomystrium, including the thick, persistent, intact cataphylls and the presence of linear raphide cells on both blade surfaces.

Map of Mesoamerican specimens with coordinates

Costa Rica Puntarenas: Parque Nacional Corcovado, 744 m, 8.31.30N 83.28.00W, 4 August 1990, Abelardo Chacón 967 (MO).
Costa Rica Puntarenas: 120 m, 08.40.00N 83.12.30W, 12 December 1988, Michael Grayum & Gerardo Herrera 9229 (MO).
Costa Rica Puntarenas: Dos Brazos de Río Tigre, 400-744 m, 08.30.35N 83.28W, 30 Aug 1990, Herrera & Fallas 4181 (CR, MO, CR).
Costa Rica Puntarenas: Osa Península, 60 m, 08.34N 83.25W, 4 March 1985, Croat & Grayum 59823 (MO).
Costa Rica Puntarenas: 450 m, 8.41.20N 83.35.40W, 16 June 1990, Herrera 3956 (CR, MO, CR).
Costa Rica Puntarenas: Parque Nacional Corcovado, 0 m, 08.28N 83.35W, 22 Nov 1981, Knapp 2192 (MO, PMA).
Costa Rica Puntarenas:, , Allen 5211 (US). Costa Rica Puntarenas: 30-40 m, 09.47N 84.37W, 11 January 1985, Michael Grayum 4764 (MO).
Costa Rica Puntarenas: Río Piro, 400 m, 08.25N 83.18.50W, 29 Oct 1990, Herrera 4538 (MO, CR).
Costa Rica Puntarenas: 100 m, 8.27N 83.33W, 16 August 1988, C. Kernan 821 (MO).
Costa Rica Puntarenas: 100 m, 8.36N 83.44W, 25 March 1989, C. Kernan & Pamela Phillips 1003 (MO).
Costa Rica Puntarenas: Rancho Quemado, 230 m, 08.41.05N 83.33.50W, 13 Aug 1991, Marin 121 (MO).
Costa Rica Puntarenas: Parque Nacional Corcovado, 2 m, 08.29N 83.36W, 1 Oct 1990, Saborio et al. 84 (MO).
Costa Rica Puntarenas: Parque Nacional Corcovado, 0-150 m, 08.27N 83.33W, , Kernan 70 (MO, CR, F, K).
Costa Rica Puntarenas: Rincón, 200 m, 08.42.45N 83.31.35W, 22 Sep 1990, Herrera 4347 (MO, CR).
Costa Rica Puntarenas:, , Pittier 6768 (BR, CR).
Costa Rica Puntarenas: Osa Península, 0-200 m, 08.29N 83.36W, , Liesner 2846 (MO).
Costa Rica Puntarenas: Osa Península, 0-5 m, 08.29N 83.36W, 6 July 1977, Liesner 2996 (MO).
Costa Rica Puntarenas: 100-200 m,, , Thomas B. Croat 35121 (MO). Costa Rica Puntarenas:, , Tonduz 6768 (BR).
Costa Rica Puntarenas: Osa Península, 50-200 m, 08.42N 83.31W, 9-12 Jan 1970, Burger & Liesner 7286 (MO, NY).
Costa Rica Puntarenas:, , Tonduz 7260 (BR, CR, US).
Costa Rica Puntarenas: Osa Península, 20-300 m,, , Liesner 1934 (MO). Costa Rica Puntarenas: 60 m, 8.36N 83.04W, 15 Sept 1987, Croat 67622 (MO).
Costa Rica Puntarenas: 300 m, 8.41.40N 83.33.35W, 16 December 1991, Reinaldo Aguilar 757 (MO).
Costa Rica Puntarenas: 08.30N 83.35W, 19 August 1984, Al Gentry & Pedro Acevedo 48690 (MO).
Costa Rica Puntarenas: 160 m, 8.40N 83.34W, 3 May 1988, Barry Hammel R. Robles & J. Marín 16812 (MO).
Costa Rica Puntarenas: 200 m, 8.38N 83.25W, 1 October 1990, Fco. Quesada 228 (MO).
Costa Rica Puntarenas: P.N. Corcovado; Península de Osa, 10 m, 08.28N 83.35W, 11 October 1993, Reinaldo Aguilar 2455 (CR).
Costa Rica Puntarenas: Fila Costeña, 900-1000 m, 08.49.02N 83.11.25W, 7 December 1993, Michael Grayum, B. Hammel, R. Aguilar & D. Gómez 10574 (CR, MO).
Costa Rica Puntarenas: R.F. Golfo Dulce; Península de Osa, 600 m, 08.43.50N 83.33.10W, 24 January 1991, Gerardo Herrera 4859 (CR, MO).
Costa Rica Puntarenas: R.F. Golfo Dulce, 1-100 m, 08.42.40N 83.45.50W, 20 July 1994, Saborio, J.C. 103 (MO).
Costa Rica Puntarenas: 50 m, 08.42.01N 83.30.48W, 11 September 1996, Thomas B. Croat & Dylan Hannon 79230 .
Costa Rica Puntarenas: 200-300 m, 08.42.00N 83.12.30W, 12 September 1996, Thomas B. Croat & Dylan Hannon 79292 (CM, MO).
Costa Rica Puntarenas: P.N. Corcovado, 200 m, 08.34N 83.31W, 2 June 1994, Aguilar, R. 3313 (INB).
Costa Rica San José: 320 m, 09.42.00N 84.23.30W, 14 May 1987, Michael Grayum, G. Herrera, G. Umaña & N. Zamora 8339 (MO).
Costa Rica San José: 460-520 m, 09.45.00N 84.33.30W, 26 June 1985, Michael H. Grayum, Richard Warner & Pam Sleeper 5478 (MO).
Costa Rica San José: 800 m, 09.44N 84.23W, 1 January 1985, Michael Grayum & Mel Baker 4694 (MO). Costa Rica San José:, , Croat 55204 (MO).
Costa Rica San José: Z.P. La Cangreja; Cerros de Puriscal, 500 m, 09.43.10N 84.23.20W, 10 Sep 1992, J.F. Morales 621 (CR).
Costa Rica San José: Z.P. La Cangreja; Cerros de Puriscal, 300 m, 09.41.50N 84.23.45W, 30 Sep 1992, J.F. Morales 726 (CR). Costa Rica San José: ca. 620-640 m, 09.43.30N 84.13.30W, 28 January 1997, M. H. Grayum, B. Hammel & F. Morales 11187 .