Like the bromeliads, the aroids (family Araceae) comprise a monocotyledonous family of both terrestrial species and others that live on trees in wet tropical forests. Tropical aroids form robust rhizomes and adventitious roots, and the adventitious roots are especially important as attachments of the plant along tree trunks, particularly among the hemiepiphytes.
Hemiepiphytes are notorious for producing a wide range of leaf forms (heteroblasty) along the stem. Very commonly, the juvenile leaves are entire or few-lobed and much smaller in size than the adult leaves, which are deeply lobed or compound.
Trash-basket epiphytes occur in a number of genera, especially in the genus Anthurium. As in orchids, root cortex may be chlorophyllous, and there has been speculation, still critically untested, that these roots also are photosynthetic organs.
CAM has not been observed at all in this family.
The majority of species in Araceae live in shade, and some species thrive on the deep-shade understory of rain forest, where a leaf may receive only brief sun flecks during the course of a typical day. These species have their maximum photosynthetic rates at less than 15% full sun, and their photosynthetic machinery is designed to get the maximum photosynthesis from what little sunlight reaches their leaves.