| | 1. Leaf blade marbled white along major veins; rhizomes deep, ± vertical, plants clumped; sterile anther tips > pollen sacs |
| |
| | 2. Inner surface of calyx tube white with several red stripes that are covered by bands of white hairs; leaf margin hairs curved toward leaf tip; anther tips pale |
| A. hartwegii |
| | 2' Inner surface of calyx tube dark red-maroon with scattered dark hairs; leaf margin hairs ± perpendicular-spreading; anther tips dark |
| A. marmoratum |
| | 1' Leaf blade uniformly green; rhizomes near soil surface, horizontal, plant generally spreading; sterile anther tips < pollen sacs |
| |
| | 3. Calyx lobes long-tapered, spreading in flower |
| A. caudatum |
| | 3' Calyx lobes obtuse to acute or abruptly soft-pointed, strongly reflexed in flower |
| A. lemmonii
|