2b. Leaf blades with 3 or more lobes, free to the base......... Section Daclylophyllium Schott

1b. Leaf blades entire or nearly so, sometimes with the anterior lobe markedly constricted at the base but never distinctly 3-lobed. 3a. Leaf blades conspicuously dark glandular-punctate at least on the lower surface.

4a. Leaf blades cordate, hastate or otherwise with usually definite posterior lobes; most basal veins usually merging with the margin of the blade before the middle of the blade..........Section Belolonchium Schott (A. verapazense alliance)

5a. Leaf blades with several pairs of basal veins sharply arcuate-ascending, extending to or almost to the apex; primary lateral veins numerous, distinct, parallel, and extending more or less straight between all the basal veins giving the leaf blade the appearance of a melastomataceous blade; number of ovules and seeds per locule unknown..........Section Digitinervium Sodiro

7a. Vernation of leaf blades involute (i.e., with both margins rolled inward toward the midrib in bud); plants frequently with a "bird's nest" habit (i.e., short stems and rosulate leaves); blades often thick, frequently more or less oblanceolate or obovate to elliptic; the primary lateral veins (at least the lower ones) joining the margins..........Section Pachyneurium Schott

7b. Vernation of leaf blades supervolute (i.e., with one margin rolled inward toward the midrib but with the alternate margin rolled around the midrib and the rolled up opposite margin, giving the "crosssectional" view a cochleate appearance); plants usually lacking a "bird's nest" habit; leaves various; the primary lateral veins frequently joining into a collective vein before reaching the margin.

8a. Stems scandent and wiry; internodes elongate, usually less than 3 mm thick, with numerous, short adventitious roots scattered along their length; flowering branches bearing 1-6 leaves; 1-ribbed cataphylls lacking; pollen inaperturate, gemmate..........Section Polyphyllium Engl.

A. flexile Schott

9a. Roots white, bearing a velamen; blades thin, narrowly oblanceolate, the primary lateral veins numerous and scarcely more prominent than the interprimary veins, stems rarely more than 1 cm diam. with persistent reddish brown, intact cataphylls: spadix with no more than 3 flowers visible per spiral (from any angle); chromosome numbers In = 40 or 60...........Section Leptanthurium Schott

9b. Roots usually greenish, lacking velamen; blades various, usually with the primary lateral veins conspicuously more prominent than the interprimary veins; stems various; cataphylls usually weathering (except section Calomystrium with cordate blades): number of flowers visible per spiral various but usually more than 3 per spiral; chromosome numbers mostly In = 30.

10 a. Leaf blades velvety, usually metallic green or blackish green in color; the epidermal cells papillate or otherwise elevated; petioles frequently ribbed; B-chromosomes present..........Section Cardiolonchium Schott

11a. Stems bearing conspicuous, thick, intact, persistent, reddish brown cata-phylls; leaf blades usually thick; the minor veins usually not prominently raised; the upper blade surface usually with linear raphide cells visible;spadix often colored and often sweetly scented; spathe usually thick, often broad. .....Section Calomystrium Schott

II b. Stems usually with cataphylls deciduous or weathering into a mass of fibers; leaf blades thick or thin; the minor veins conspicuous or not; the upper surface usually lacking raphide cells; spadix various, less frequently scented; spathe various, often lanceolate. 12a. Leaf blades much longer than broad, oblong to linear (rarely ovate but then thin, veiny, and weakly bullate in A. davidsoniae). 13a. Stems elongate, erect to scandent, 7-20 mm diam.; berries frequently green..........Section Xialophyllium Schott

13b. Stems short; the internodes short; stems mostly less than 10 mm diam.; berries usually not green (except in A. caperatum and A. panduriforme).

14a. Flowers with pistils early emergent, usually held considerably above the tepals at anthesis; spathe conspicuously decurrent..........Section Oxycarpium Schott