The altitudinal distribution of Heliamphora ranges from 860 m above sea level for populations of H. neblinae on Cerro Avispa to as much as 2994 m for plants of H. hispida growing near the summit of Pico da Neblina in Cerro de la Neblina.[2]
Key
Tepui names shown in the tables are those used in Flora of the Venezuelan Guayana and Sarraceniaceae of South America, with alternate names and spellings given in brackets. Many additional orthographic variants are likely to exist and some localities remain the subject of considerable toponymic confusion; these cases are covered in the Notes section. Many of the tepui heights are approximate and likely to change as more accurate measurements become available. Only tepuis known to support Heliamphora are included in the tables (for example, not all parts of the Chimantá Massif or Eastern Tepuis chain are listed). Formally described species are listed first, followed by undescribed species, and finally natural hybrids. Where published information is available, the altitudinal distribution of a taxon at a particular locality is given. In cases of unconfirmed locality records, the taxon name is preceded by a question mark (?).
Coordinates given correspond to the approximate centre points of tepui summit plateaus (though in the case of fragmented tepui complexes such as Cerro de la Neblina, the centre point itself may not lie on any plateau). Unless otherwise indicated, all other information presented in the tables is sourced from Sarraceniaceae of South America.
Distribution of currently recognised Heliamphora species[2]
Map of Venezuela showing the major tepuis, massifs and uplands to which Heliamphora are native. The distribution of this genus is highly disjunct, with all known species concentrated in three major areas: the Duida and Neblina complexes of Amazonas, and the tepuis and uplands of southeastern Bolívar.[2]
Western range
The western range of the genus is confined almost entirely to Amazonas state, Venezuela, but extends slightly into northernmost Brazil.
Neblina Massif
The Neblina Massif is located in the extreme south of Amazonas and is dominated by the highly fragmented complex known as Cerro de la Neblina. This complex has many plateaus averaging 2000–2400 m in elevation, and includes Brazil's two highest peaks: Pico da Neblina (2994 m) and Pico 31 de Março (2973 m), known as Pico Phelps in Venezuela.[nb b] A giant valley, Cañón Grande, runs southwest to northeast through the middle of Cerro de la Neblina. The smaller outcrops of Cerro Aracamuni and Cerro Avispa, both reaching approximately 1600 m, lie to the north of this complex.[3] The name Neblina Massif is sometimes applied specifically to Cerro de la Neblina, to the exclusion of Cerro Aracamuni and Cerro Avispa.[2]
Four species are native to this area, all local endemics: H. ceracea, H. hispida, H. neblinae, and H. parva, though only the range of H. neblinae extends to the two northern cerro-plateaus. No Heliamphora are found on the small granitic outcrop of Cerro Aratitiyope (1700 m) to the north of the Neblina Massif.[2]
Known only from several small populations on slopes of Pico da Neblina in Brazil, but may have wider distribution. If not, it would be the only known species not found in Venezuela.
Found in southern portion of Cerro de la Neblina, on and around Pico da Neblina and Pico 31 de Março (including area around the Titirico River). Additional populations may grow in the largely unexplored Cañón Grande. Plants near the summit of Pico da Neblina (2994 m) represent the upper altitudinal limit for the genus.
Known with certainty from southern portion of Cerro de la Neblina, where it grows on and around Pico da Neblina. Herbarium material suggests it is also present in the northern parts, though it has not been observed in the extreme north.
Recorded from southern part of Cerro de la Neblina around Pico da Neblina at 2000–2200 m, though the largest known stands grow in the northwestern part of the massif, at lower elevations of 1750–1850 m. It is unknown whether the range of this species extends into the central valleys of Cerro de la Neblina.
Two species are recognised from this complex and found nowhere else: H. macdonaldae and H. tatei. A third described species, H. tyleri, is universally treated as a synonym of H. tatei.[2]
Found on summits, ridge tops, and slopes. It is unknown whether this plant is present on the northern summit plateau of Fufha.
Eastern range
The eastern range of the genus includes the vast majority of species. It is largely encompassed by Bolívar state, Venezuela, but also extends into portions of western Guyana and northern Brazil.
Angasima and Upuigma
The imposing peaks of Angasima Tepui (2250 m) and Upuigma Tepui (2100 m) lie south of the much larger Chimantá Massif, from which they are separated by the Río Aparurén valley.[3] Three Heliamphora species are native to Angasima Tepui: the undescribed endemic H. sp. 'Angasima Tepui' and two species shared with the nearby Chimantá Massif (H. huberi and H. pulchella). Only the range of H. pulchella extends to the isolated peak of Upuigma Tepui.[2]
The Eastern Tepuis chain, or Roraima–Ilú range, stretches in a northwesterly direction from the tripoint of Brazil, Guyana, and Venezuela, closely following the Guyana–Venezuela border, with an isolated double-peaked plateau (Serra do Sol or Uei Tepui) to the south. Moving in a northwesterly direction from Serra do Sol (2150 m), the major summits of this chain are Mount Roraima (2810 m), Kukenán Tepui (2650 m), Yuruaní Tepui (2400 m), Wadakapiapué Tepui (2000 m), Karaurín Tepui (2500 m), Ilú Tepui (2700 m), and Tramen Tepui.[3] With the exception of the tiny Wadakapiapué Tepui (5°18′59″N60°55′23″W / 5.316261°N 60.923017°W / 5.316261; -60.923017 (Wadakapiapué Tepui)), all of these peaks are known to support Heliamphora. The Eastern Tepuis chain includes some of the most widely visited tepuis, particularly Roraima and nearby Kukenán. The Ilú (Uru) and Tramen Tepuis are treated here as a single locality since they are joined by a common base and share the same assemblage of Heliamphora taxa.[2][3]
Found on western slopes and foothills of Ilú–Tramen Massif. Lower altitudinal limit is not known, but type specimen was collected at elevation of around 1500 m.
Most abundant in the valley between Ilú and Tramen Tepuis, where it grows both at the base of cliffs and on cliff faces. Only a small number of stunted plants are known from the summits of the Ilú–Tramen Massif. Its altitudinal limits and the full extent of its distribution remain unknown.
Presence suggested by herbarium specimen of putative H. arenicola × H. ionasi hybrid collected on western shoulder of Karaurín Tepui at 1950 m altitude.
Presence suggested by herbarium specimen of putative H. arenicola × H. ionasi hybrid collected on western shoulder of Karaurín Tepui at 1950 m altitude.
Lowest-growing population known, found just below the summit of the plateau. Also present on minor plateaus nearby, which form a chain between Serra do Sol and Mount Roraima.
Found in small, scattered populations in northern portion of summit plateau (including around tripoint). Growing at roughly 2750 m, these stunted plants represent the upper altitudinal limit of the species. Lowest altitude populations (1200 m) grow on slopes off the mountain's northern flank. Distribution may similarly extend eastwards from Mount Roraima, but this requires confirmation.
Found mostly around edges of mountain and on upper tepui cliffs. Summit plateau hosts highest-growing population of this species, at 2700 m. Originally discovered in "El Dorado Swamp" off Mount Roraima's southern flank, but this population has not been relocated since its discovery and was possibly destroyed by fires.
Summit supports the largest known populations of this species, unusually consisting of predominantly green-pitchered plants. Only known Venezuelan locality for this species is at the southern end of the plateau.
Los Testigos, or the Aparamán range, is a chain of four rather small and floristically similar tepuis forming a bridge between Auyán Tepui in the west and Ptari Tepui in the east. From west to east the four major peaks are: Aparamán Tepui (2100 m), Murisipán Tepui (2350 m), Tereke-yurén Tepui (1900 m), and Kamarkawarai Tepui (2400 m), the latter three sharing a common slope area.[3] There however remains some confusion in the literature regarding the names of these peaks.[nb e]
Restricted to flat summit. Complex backcrosses are common and may outnumber the parent species in some areas.
The flat, symmetrical peak on the left is Ptari Tepui, with the long southwestern face of Sororopán Tepui extending to the right.
Uplands
The uplands of the Venezuelan Guayana are regarded as those areas with an elevation of approximately 500–1500 m, with higher elevations being highland and lower ones lowland.[3]
The Gran Sabana (literally "Great Savannah") is a vast area of tropical uplands covering nearly 30,000 km2, which surrounds many of the tepuis of the eastern range. It gradually rises in elevation from 750 m in the south to 1450 m in the north.[3] The rocky uplands of Sierra de Lema and Sierra Senkopirén lie to the north and northwest of the Gran Sabana and surround the Auyán Massif. They have an elevational range of around 700 to 1650 m.[3]Cerro Venamo is a sandstone mountain near the border between Venezuela and Guyana, at the northeastern tip of the Gran Sabana. With a height of 1600 m it falls somewhere between an upland and a true highland area.[3] As with many other localities in the Guayana Highlands, the name Cerro Venamo has been inconsistently applied to a number of adjacent areas.[nb f]
b.^ For 39 years, based on an uncontested measurement performed in 1965 by topographer José Ambrósio de Miranda Pombo, using a theodolite, the elevation of Pico da Neblina was thought to be 3,014 metres (9,888 ft), but a much more accurate measurement performed in 2004 with state-of-the-art GPS equipment by cartographer Marco Aurélio de Almeida Lima, a member of a Brazilian army expedition, puts it at 2,994 m (9,823 ft). This is now recognised by the Brazilian Institute of Geography and Statistics (IBGE), the federal government's official geographic survey and census agency, which jointly organised the expedition. The height of Pico 31 de Março / Pico Phelps was similarly reduced from 2,992 m (9,816 ft) to 2,973 m (9,754 ft).[8]
c.^ There is some discrepancy between published sources with respect to the distribution of H. minor var. pilosa: the formal description of Fleischmann & Grande Allende (2012) states that this variety is endemic to the northern portion of the summit plateau of Auyán Tepui,[5] while in Sarraceniaceae of South America (co-authored by Fleischmann) its range is said to encompass both Auyán Tepui and Cerro La Luna, with photographs from both localities included.[2]
e.^Otto Huber summarised this muddled toponymy as follows: "There is, however, confusion concerning the precise names of the two central mountains; according to Brewer-Carías (1978), Murochiopán-tepui is the name of a smaller lateral mountain of Aparamán [5°52′32″N62°06′48″W / 5.875429°N 62.113452°W / 5.875429; -62.113452 (lateral mountain of Aparamán Tepui)], followed to the east by the high Tereke Yurén-tepui and the lower Tucuy-wo-cuyén-tepui, whereas members of the Terramar Foundation expeditions (Steyermark 1986a; Holst 1987; George 1988) apply the name Murisipán-tepui to Brewer's Tereke Yurén-tepui, and the name Tereke-yurén-tepui to Brewer's Tucuy-wo-cuyén-tepui, omitting the name of the smaller lateral mountain of Aparamán-tepui."[3] A yet different sequence (and spelling) of names can be found in, for example, the formal description of H. folliculata, namely: Murosipan, Aparaman, Tereke-Yuren, and Kamarkaiwaran.[13]
^Nogué, S., V. Rull, E. Montoya, O. Huber & T. Vegas-Vilarrúbia (October 2009). Paleoecology of the Guayana Highlands (northern South America): Holocene pollen record from the Eruoda-tepui, in the Chimantá massif. Palaeogeography, Palaeoclimatology, Palaeoecology281(1–2): 165–173. doi:10.1016/j.palaeo.2009.07.019
^Briceño, H., C. Schubert & J. Paolini (1990). Table-mountain geology and surficial geochemistry: Chimantá Massif, Venezuelan Guayana Shield. Journal of South American Earth Sciences3(4): 179–194. doi:10.1016/0895-9811(90)90002-I
^Kok, P.J.R. (2008). A new highland species of Arthrosaura Boulenger, 1885 (Squamata: Gymnophthalmidae) from Maringma tepui on the border of Guyana and Brazil. Zootaxa1909: 1–15. ["first page"(PDF).]
^Kok, P.J.R. (2009). Lizard in the clouds: a new highland genus and species of Gymnophthalmidae (Reptilia: Squamata) from Maringma tepui, western Guyana. Zootaxa1992: 53–67. ["first page"(PDF).]
^Fleischmann, A., A. Wistuba & S. McPherson (21 December 2007). Drosera solaris (Droseraceae), a new sundew from the Guayana Highlands. Willdenowia37(2): 551–555. doi:10.3372/wi.37.37214
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