The genus Heliamphora ( or ; Greek: helos "marsh" and amphoreus "amphora") contains 23 species of pitcher plants endemic to South America. The species are collectively known as sun pitchers, based on the mistaken notion that the heli of Heliamphora is from the Greek helios, meaning "sun". In fact, the name derives from helos, meaning marsh, so a more accurate translation of their scientific name would be marsh pitcher plants. Species in the genus Heliamphora are carnivorous plants that consist of a modified leaf form that is fused into a tubular shape. They have evolved mechanisms to attract, trap, and kill insects; and control the amount of water in the pitcher. At least one species (H. tatei) produces its own proteolytic enzymes that allows it to digest its prey without the help of symbiotic bacteria. Morphology All Heliamphora species are herbaceous perennial plants that grow from a subterranean rhizome. Heliamphora species form stemless rosettes and leaf height ranges from a few centimeters (H. minor, H. pulchella) up to more than (H. ionasi, H. tatei). Heliamphora possess tubular traps formed by rolled leaves with fused edges. Marsh pitcher plants are unusual among pitcher plants in that they lack lids (opercula), instead having a small "nectar spoon" on the upper posterior portion of the leaf. This spoon-like structure secretes a nectar-like substance, which serves as a lure for insects and small animals. Each pitcher also exhibits a small slit in its side that allows excess rainwater to drain away, similar to the overflow on a sink. This allows the marsh pitcher plants to maintain a constant maximum level of rainwater within the pitcher. The pitchers' inner surface is covered with downward-pointing hairs to force insects into the pitchers' lower parts. Carnivory Though often counted among the various carnivorous plants, with the exception of Heliamphora tatei, the vast majority of plants in the genus Heliamphora do not produce their own digestive enzymes (i.e. proteases, ribonucleases, phosphatases, etc.), relying instead on the enzymes of symbiotic bacteria to break down their prey. They do, however, attract prey through special visual and chemical signals and trap and kill the prey through a typical pitfall trap. Field studies of H. nutans, H. heterodoxa, H. minor, and H. ionasi have determined that none of these species produce their own proteolytic enzymes. H. tatei is one of the few species observed to produce both digestive enzymes and wax scales,