The genus Heliamphora ( or ; Greek: helos "marsh" and amphoreus "amphora") contains 24 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". The name instead derives from the Greek 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). 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. The morphological diversification of Heliamphora pitchers is both convergent and divergent, likely as a result of adaptive radiation in the geographically complex Guiana highland.
center|thumb|950x950px|Phylogeny of Heliamphora inferred from nuclear DNA and the evolution of morphological characters. The drainage slit is only found in the E1 clade. In the rest of Heliamphora, the drainage hole is present. The study (A: entire plant; B: [[androecium; C: stamen; D: pistil; E: transverse section of the ovary; F: seed, with the testa; G: vertical section of the seed; H: embryo)]]
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, which also aid in prey capture.. Among these, a lineage of SWEET sugar transporters is up-regulated and appears to be evolving rapidly, consistent with specialization for nectar production. In addition, genes associated with volatile organic compound synthesis — many of which are also known from floral scent pathways — are active in the nectar spoon, suggesting a genetic basis for scent-mediated prey attraction . These findings indicate that ancient, conserved plant genes have been repurposed during the evolution of H. tatei carnivory to facilitate the production of both nectar rewards and attractive scents, enhancing prey visitation. This molecular recruitment underscores that prey attraction in Heliamphora is not solely a morphological or ecological trait but also involves distinct genetic adaptations in H. tatei
Care in cultivation
Heliamphora are regarded by carnivorous plant enthusiasts and experts as one of the more difficult plants to maintain in cultivation. The genus requires cool (the "highland" species) to warm (the "lowland" species) temperatures with a constant and very high humidity. An amateur botanist in New York City has shown that cultivation of the genus can be achieved with an inexpensive setup consisting of a large plastic crate, a fan, egg cartons, and water bottles filled with ice. The highland species, which originate from high on the humid tepui mountaintops, include H. nutans, H. ionasi, and H. tatei. The lowland Heliamphora, such as H. ciliata and H. heterodoxa have migrated to the warmer grasslands at the foot of the tepuis.
Shredded, long-fibered, or live sphagnum moss is preferred as a soil substrate, often with added horticultural lava rock, perlite, and pumice. The substrate must always be kept moist and extremely well drained. Misting Heliamphora with purified water is often beneficial to maintain high humidity levels.
Propagation through division only has a limited rate of success, as many plants that are divided go into shock and eventually die. Germination of Heliamphora seed is achieved by scattering it on milled sphagnum moss and keeping in bright light and humid conditions. Seed germination begins after many weeks.
Classification
The genus Heliamphora contains the most species in the Sarraceniaceae family and is joined by the cobra lily (Darlingtonia californica) and the North American pitcher plants (Sarracenia spp.) in that taxon.
Species
Twenty-four species of Heliamphora are currently recognized. Years given denote the year of the species's formal publication under the current name, not the earlier basionym date of publication if one exists.
{| class="sortable wikitable"
! Species !! Authority !! Year !! Image !! Distribution !! Altitudinal distribution
|-
| Heliamphora arenicola || Wistuba, A.Fleischm., Nerz & S.McPherson || 2002 || 80px || Venezuela || 1900–2100 m
|-
| Heliamphora ciliata || Wistuba, Nerz & A.Fleischm. || 2009 || || Venezuela || 900 m
|-
| Heliamphora collina || Wistuba, Nerz, S.McPherson & A.Fleischm. || 2004 || || Venezuela || 1800–2600 m
|-
| Heliamphora exappendiculata || (Maguire & Steyermark) Nerz & Wistuba || 2006 || || Venezuela || 1700–2100 m
|-
| Heliamphora folliculata || Wistuba, Harbarth & Carow || 2001 || 80px || Venezuela || 1700–2400 m
|-
| Heliamphora glabra || (Maguire) Nerz, Wistuba & Hoogenstrijd || 2006 || || Borderlands of Brazil, Guyana, and Venezuela || 1200–2750 m
|-
| Heliamphora heterodoxa || Steyerm. || 1951 || || Guyana?, Venezuela || 1200–2200 m
|-
| Heliamphora hispida || Nerz & Wistuba || 2000 || || Border between Brazil and Venezuela || 1800–3014 m
|-
| Heliamphora huberi || A.Fleischm., Wistuba & Nerz || 1978 || 80px || Venezuela || 1800–2600 m
|-
| Heliamphora macdonaldae || Gleason || 1931 || 80px || Venezuela || 1500–2300 m
|-
| Heliamphora minor || Gleason || 1939 || 80px || Venezuela || 1650–2500 m
|-
| Heliamphora neblinae || Maguire || 1840 || 80px || Borderlands of Brazil, Guyana, and Venezuela || 2000–2700 m
|-
| Heliamphora parva || (Maguire) S.McPherson, A.Fleischm., Wistuba & Nerz || 2005 || 80px || Venezuela || 1850–2550 m
|-
| Heliamphora purpurascens || Wistuba, A.Fleischm., Nerz & S.McPherson || 2005 || || Venezuela || 2400–2450 m
|-
| Heliamphora tatei || Gleason Additionally, an undescribed variant of H. pulchella , with traps lacking long retentive hairs is known from Amurí Tepui.
Natural hybrids
At least eleven natural hybrids have been recorded:
Phylogeny and Diversification
Closely related species tend to be geographically closely distributed. Major Heliamphora clades probably emerged through both geographical separation and dispersal in the Guiana Highlands during Miocene with more recent diversification driven by vertical displacement during the Pleistocene glacial-interglacial thermal oscillations.
[[File:Heli phylo.jpg|thumb|1000x1000px|Evolutionary History of Heliamphora inferred from nuclear DNA. The evolutionary time is represented in millions of years. The node bars represent uncertainty in ancestral age estimations.