Anthurium chamulense ssp. oaxacanum Croat, ssp. nov.

TYPE: Mexico. Oaxaca: along road from Teotitlan del Camino lo Santa María Chilchotia, 4.4 mi beyond tumoffto Huatia de Jimenez, elev. 1,980 m, steep slopes with huge boulders, Croat 48389 (MO-2682519, holotype; F, K, MEXU, SEL, US, isotypes:
Live at MO).

Anthurium chamulense ssp. oaxacanum a ssp. chamulense laminis tenuioribus, nervis lertiaribus supra vix impressis subtus manifestis differt.

Epiphyte; stems narrow, 1.5 cm diam.; leaf scars 1.2 cm wide; roots thick, brown; cataphylls subcoriaceous, 4-7 cm long, drying medium brown (B & K Yellow 4/10), persisting as reticulate fibers.

LEAVES erect-spreading; petioles 22-30 cm long, 4-6 mm diam., D-shaped, bluntly sulcate, the margins sharper near base of blade; geniculum 1-1.3 cm long, sometimes tinged red-violet; blades subcoriaceous, triangular, 24-48 cm long, 8-13 cm wide, broadest 1-2 cm from base, gradually acuminate at apex, obtuse to truncate at base; anterior lobe 23.5-27 cm long, the margins straight; posterior lobes 4-5.5 cm long, directed upward; sinus arcuate to arcuate with petiole decurrent, rounded at apex; upper surface glossy, lower surface matte: midrib bluntly raised at base, sunken to flat at apex above, raised below; basal veins 3-4 pairs, the second to fourth coalesced 1-1.5 cm, prominulous above and below; posterior ribs naked, the outer margins rolled up; primary lateral veins 3-6 per side, departing midrib at 30°-45° angle, sunken above, raised below, straight to collective vein; lesser veins scarcely visible; collective vein arising from the first or second basal vein, running to the apex, 3-5 mm from margin, sunken above, raised below.

INFLORESCENCE spreading, shorter or as long as leaves; peduncle terete, green, tinged with red-violet, 30-32 cm long, 3-4 mm diam.;
spathe green, subcoriaceous, ± triangular, ca. 3 cm long, 1 cm wide; spadix violet-purple, tan at anthcsis, 4.5-5 cm long, 5-6 mm diam. at base, 3-4 mm diam. al apex; flowers rhombic, 3 mm in both directions, the sides straight to weakly sigmoid; 3-6 flowers visible in the principal spiral, 4-8 flowers visible in the alternate spiral;tepals matte, weakly punctate, minutely papillate, lateral tepals ca. 1.5 mm wide, the inner margin convex; pistils weakly emergent; stigma linear; stamens emerging from base, laterals first, preceding alternates by 3-4 spirals, held over pistil in tight cluster; anthers white; thecae ellip-soid, not divaricate; pollen white lo cream.

INFRUCTESCENCE pendent; berries pale orange, truncate at apex, trapezoidal in side view, ca. 10 mm long, 8-11 mm diam.; mesocarp juicy, fleshy with numerous, whitish raphide cells; seeds 2, greenish white, obovate, depressed at apex, round at base, flattened, ca. 7 mm long, 6 mm wide, 3.1-3.4 mm thick, enveloped in a thin, sticky substance, slightly longer on ends than at sides of seeds. Figs. 33 and 39.

Anthurium chamulense ssp. oaxacanum is known only from the type locality in northern Oaxaca in "selva alta perennifolia" at nearly 2,000 m. The taxon is recognized by its relatively thinner, usually truncate, narrowly triangular leaves, sulcate petiole, green spathe and short, usually stipitate, violet-purple spadix. It is a member of section Belolonchium. The subspecies oaxacanum is not confused with any other taxon from that part of Mexico. It is separated from A. chamulense ssp. chamulense by having thinner leaf blades with less conspicuously impressed tertiary veins on the upper surface but with the tertiary veins on the lower surface clearly visible. In subspecies chamulense the tertiary veins on the lower surface
are scarcely visible. In addition the subspecies oaxacanum occurs in much wetter forest ("selva alta perennifolia") than ssp. chamulense ("bos-que pino-encino").

Mexico Chiapas: 1820 m.,, 16 July 1956, Kaplan 106 ch 56 (LL). Mexico Oaxaca:, , Thomas B. Croat 48389 (F, K, MEXU, MO, SEL, US).