Nepenthes gantungensis
Encyclopedia
Nepenthes gantungensis is a tropical pitcher plant
Pitcher plant
Pitcher plants are carnivorous plants whose prey-trapping mechanism features a deep cavity filled with liquid known as a pitfall trap. It has been widely assumed that the various sorts of pitfall trap evolved from rolled leaves, with selection pressure favouring more deeply cupped leaves over...

 known from a single peak on the Philippine
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

 island of Palawan
Palawan
Palawan is an island province of the Philippines located in the MIMAROPA region or Region 4. Its capital is Puerto Princesa City, and it is the largest province in the country in terms of total area of jurisdiction. The islands of Palawan stretch from Mindoro in the northeast to Borneo in the...

, where it grows at elevations of 1600–1784 m above sea level.

Botanical history

The species was discovered in early 2010 by Jehson Cervancia, Mark Jaunzems, Ch'ien Lee
Ch'ien Lee
Ch'ien C. Lee is a photographer and botanist specialising in the carnivorous plant genus Nepenthes. Lee has described several new Nepenthes species, including N. chaniana, N. gantungensis, N. glandulifera, N. jamban, N. lingulata, N. palawanensis, N. pitopangii,...

, and Stewart McPherson
Stewart McPherson (geographer)
Stewart R. McPherson is a British geographer.He studied at the University of Durham in England, the University of Tübingen in Germany and Yale University in the United States....

. The find was announced on the internet on February 28, 2010, under the placeholder name
Placeholder name
Placeholder names are words that can refer to objects or people whose names are either temporarily forgotten, irrelevant, or unknown in the context in which they are being discussed...

 "Nepenthes sp. G". At this point McPherson was uncertain whether the taxon represented a new species or merely a variant of N. mira
Nepenthes mira
Nepenthes mira is a highland pitcher plant endemic to Palawan in the Philippines. It grows at elevations of 1550–1605 m above sea level....

, and asked for input from carnivorous plant
Carnivorous plant
Carnivorous plants are plants that derive some or most of their nutrients from trapping and consuming animals or protozoans, typically insects and other arthropods. Carnivorous plants appear adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic...

 hobbyists who had cultivated the latter.

Nepenthes gantungensis was formally described
Species description
A species description or type description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously, or are...

 by McPherson, Cervancia, Lee, Jaunzems, François Mey, and Alastair Robinson
Alastair Robinson
Dr. Alastair S. Robinson is a British-American taxonomist and field botanist specialising in the carnivorous plant genus Nepenthes...

, in the second volume of McPherson's Carnivorous Plants and their Habitats, published in July 2010. The specific epithet gantungensis refers to Mount Gantung, the only locality from which it is known. The description was accompanied by nine figures, consisting of eight habitat photographs and a pencil drawing by François Mey showing the species's major anatomical features.

The herbarium
Herbarium
In botany, a herbarium – sometimes known by the Anglicized term herbar – is a collection of preserved plant specimens. These specimens may be whole plants or plant parts: these will usually be in a dried form, mounted on a sheet, but depending upon the material may also be kept in...

 specimen S.McPherson SRM 4 is the designated holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

, and is deposited at the herbarium of Palawan State University
Palawan State University
The Palawan State University is a government-funded university in Puerto Princesa, Palawan, Philippines. -History:PSU was established on March 2, 1972, as a teacher-training institution known as the Palawan Teachers College by virtue of Republic Act 4303 with Dr. Walfrido R. Ponce de Leon as...

 (PPC) in Puerto Princesa City
Puerto Princesa City
The City of Puerto Princesa is a city located on the western provincial island of Palawan, one of 80 provinces which make up the Philippines...

. It was collected on January 25, 2010, from the summit area of Mount Gantung at 1754 m altitude. In preparing the species description, the describing authors also examined herbarium material of a number of closely allied species, including N. attenboroughii
Nepenthes attenboroughii
Nepenthes attenboroughii is a montane species of insectivorous pitcher plant of the genus Nepenthes. It is named after the celebrated broadcaster and naturalist Sir David Attenborough, who is a keen enthusiast of the genus. The species is characterised by its large and distinctive bell-shaped...

(specimens A.Robinson AR001 and AR002), N. mantalingajanensis
Nepenthes mantalingajanensis
Nepenthes mantalingajanensis is a tropical pitcher plant known only from the summit region of Mount Mantalingajan, the highest point on the Philippine island of Palawan, after which it is named.-Botanical history:...

(G.C.G.Argent & E.M.Romero 92114), N. mira
Nepenthes mira
Nepenthes mira is a highland pitcher plant endemic to Palawan in the Philippines. It grows at elevations of 1550–1605 m above sea level....

(G.C.G.Argent et al. 25438), and N. rajah
Nepenthes rajah
Nepenthes rajah is an insectivorous pitcher plant species of the Nepenthaceae family. It is endemic to Mount Kinabalu and neighbouring Mount Tambuyukon in Sabah, Malaysian Borneo. Nepenthes rajah grows exclusively on serpentine substrates, particularly in areas of seeping ground water where the...

(Low s.n.).

Description

Nepenthes gantungensis is an upright, climbing or scrambling plant. The stem
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...

, which may be branched in vining plants, reaches a maximum length of around 4 m. It is cylindrical and varies in diameter from 2.5 to 3.5 cm. Internodes are typically 2–20 cm long, becoming elongated in climbing specimens.
Leaves are petiolate to subpetiolate and coriaceous in texture. The lamina (leaf blade) is narrowly oblong and measures 20–40 cm in length by 6–12 cm in width. The laminar apex is acute or rounded. The base may be shortly attenuate or obtuse, and encircles the stem for two-thirds to the entirety of its circumference. Tendril
Tendril
In botany, a tendril is a specialized stem, leaf or petiole with a threadlike shape that is used by climbing plants for support, attachment and cellular invasion by parasitic plants, generally by twining around suitable hosts. They do not have a lamina or blade, but they can photosynthesize...

s are up to 40 cm long, with those supporting upper pitchers being coiled.

Rosette and lower pitchers are wholly ovate to urceolate. They grow up to 20 cm high by 7 cm wide. A pair of wings up to 12 mm wide runs down the ventral surface of the pitcher cup. These wings bear filiform fringe elements up to 10 mm long. The pitcher mouth is oval to circular and up to 6 cm across. It has an oblique insertion and rises at the rear to form a conspicuous neck. The peristome
Peristome
The word peristome is derived from the Greek peri, meaning 'around' or 'about', and stoma, 'mouth'. It is a term used to describe various anatomical features that surround an opening to an organ or structure. The term is used in plants and invertebrate animals, such as in describing the shells of...

 is cylindrical to slightly flattened and up to 2 cm wide for most of its length, becoming broader towards the neck (≤3 cm wide). It bears ribs up to 2 mm high and spaced up to 2 mm apart, which terminate in teeth (≤4 mm long) on the peristome's inner margin. The digestive zone usually covers the entirety of the pitcher's inner surface. The pitcher lid or operculum
Operculum (botany)
An operculum, in botany, is a term generally used to describe a structure within a plant, moss, or fungus acting as a cap, flap, or lid. In plants, it may also be called a bud cap.Examples of structures identified as opercula include:...

 is elliptic and measures up to 6 cm in length by 4.5 cm in width. It lacks appendages or a keel. A spur is inserted near the base of the lid. It measures up to 9 mm in length, with a basal diameter of up to 2 mm, although it may be much smaller.

Upper pitchers are frequently produced. They are variably funnel-shaped, ranging from wholly infundibular to infundibular only in the basal two-thirds and cylindrical above. They may be somewhat larger than their terrestrial counterparts, reaching 25 cm in height by 7 cm in width, though they rarely reach these maximum dimensions. The wings are commonly reduced to a pair of ribs. Aerial traps resemble terrestrial ones in other respects.

Nepenthes gantungensis is known to flower both in the rosette
Rosette (botany)
In botany, a rosette is a circular arrangement of leaves, with all the leaves at a single height.Though rosettes usually sit near the soil, their structure is an example of a modified stem.-Function:...

 stage and as a vining plant. The species has a racemose
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...

 inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

. Male inflorescences can reach a height of 60 cm, of which the rachis
Rachis
Rachis is a biological term for a main axis or "shaft".-In zoology:In vertebrates a rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually form the supporting axis of the body and is then called the spine or vertebral column...

 constitutes up to 30 cm. Female inflorescences are similar in size, growing to 50 cm in length. Peduncles
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...

 of both sexes have a basal diameter of approximately 1 cm. Female inflorescences hold up to around 150 closely packed flowers that are usually restricted to the distal quarter of their length. Flowers are most commonly borne entirely on one-flowered pedicels
Pedicel (botany)
A pedicel is a stem that attaches single flowers to the main stem of the inflorescence. It is the branches or stalks that hold each flower in an inflorescence that contains more than one flower....

, but some plants may have a combination of these and two-flowered partial peduncles. Fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

s are up to 8 mm long. As in most Nepenthes species, the seeds are filiform. They are pale brown and measure around 7 mm in length.

A dense indumentum
Indumentum
The indumentum is a covering of fine hairs or bristles on a plant or insect.In plants, the indumentum types are:*pubescent*hirsute*pilose*villous*tomentose*stellate*scabrous*scurfy...

 of simple, reddish-brown hairs (≤3 mm long) is present on the undersides of the tendrils. These hairs are caducous, being lost with age. Shorter hairs of up to 2 mm are sparsely distributed on laminar margins and the outer surfaces of developing pitchers. These hairs turn silvery with age.

Colouration of the vegetative parts is variable. The laminae and petioles are often green throughout when produced in shaded conditions and red to purple in plants exposed to direct sunlight. Both lower and upper pitchers are predominantly green to yellow on their outer surfaces, often flecked with red to purple markings on the interior. Wholly red or purple lower pitchers have not been recorded. The peristome is often red, purple or brown in lower pitchers and orange to red in uppers. The lid is yellow to orange, sometimes tinged red.

Ecology

Nepenthes gantungensis is endemic to the Philippine
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

 island of Palawan
Palawan
Palawan is an island province of the Philippines located in the MIMAROPA region or Region 4. Its capital is Puerto Princesa City, and it is the largest province in the country in terms of total area of jurisdiction. The islands of Palawan stretch from Mindoro in the northeast to Borneo in the...

. It has only been recorded from the upper slopes of Mount Gantung in Brooke's Point
Brooke's Point, Palawan
Brooke's Point is a 1st class municipality in the province of Palawan, Philippines.Named after Sir James Brooke, the municipality has become famous for its promotion of ecotourism...

 municipality, where it has an altitudinal distribution of 1600–1784 m above sea level. The only known population comprises several hundred individuals.

The species grows terrestrially. It is most abundant above 1650 m, where it is found among stunted montane scrub vegetation
Shrubland
Shrubland, scrubland, scrub or brush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity...

 on the summit and summit ridge, and forms a frequently-flowering, compact rosette
Rosette (botany)
In botany, a rosette is a circular arrangement of leaves, with all the leaves at a single height.Though rosettes usually sit near the soil, their structure is an example of a modified stem.-Function:...

. The most vigorous populations are said to grow in "sheltered scrub, amongst boulders just below the summit". Etiolated
Etiolation
Etiolation is a process in flowering plants grown in partial or complete absence of light. It is characterized by long, weak stems; smaller, sparser leaves due to longer internodes; and a pale yellow color . It increases the likelihood that a plant will reach a light source, often from under the...

 vining plants of N. gantungensis have been found above 1600 m in "shrubby montane forest". Specimens growing in such shaded conditions climb to the height of the canopy. Like its close relatives, N. gantungensis is apparently outcompeted by bamboo
Bamboo
Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....

. It is not sympatric with other Nepenthes species and no natural hybrids involving it have been recorded.

The conservation status
Conservation status
The conservation status of a group of organisms indicates whether the group is still extant and how likely the group is to become extinct in the near future...

 of N. gantungensis has not been formally assessed for the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...

, but the describing authors suggested it be considered Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....

 based on the IUCN criteria, due to its localised distribution and small population size. The natural habitat of this species remains, for the most part, untouched by human activity, although a radio repeater
Radio repeater
A radio repeater is a combination of a radio receiver and a radio transmitter that receives a weak or low-level signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. This article refers to professional, commercial, and...

 tower and a small building are present near the summit. Mount Gantung lies within the Mount Mantalingajan protected area, but "large scale commercial mining operations" have nonetheless continued on a nearby summit.

Related species

The describing authors of N. gantungensis identified N. deaniana
Nepenthes deaniana
Nepenthes deaniana is a tropical pitcher plant endemic to the Philippines, where it grows at an altitude of 1180–1296 m above sea level. The species is known only from the summit region of Thumb Peak, a relatively small, ultramafic mountain in Puerto Princesa Province, Palawan.Nepenthes...

and N. mira
Nepenthes mira
Nepenthes mira is a highland pitcher plant endemic to Palawan in the Philippines. It grows at elevations of 1550–1605 m above sea level....

as its closest relatives. All three species are only known from isolated Palawan peaks. Nepenthes gantungensis can be distinguished from both on the basis of its typically shorter and narrower laminae, which have a more acute apex and base, as well as on the structure of the inflorescence, in which all flowers may be borne singly on pedicels. Compared to N. deaniana, the inflorescence of N. gantungensis is usually considerably longer. There are also differences in pitcher morphology, including a more pronounced peristome in N. gantungensis. Whereas the lower pitchers of N. deaniana and N. mira may be reddish-purple throughout, those of N. gantungensis are not known to exhibit such dark pigmentation. Unlike its close relatives, N. gantungensis frequently produces upper pitchers.

Nepenthes mantalingajanensis
Nepenthes mantalingajanensis
Nepenthes mantalingajanensis is a tropical pitcher plant known only from the summit region of Mount Mantalingajan, the highest point on the Philippine island of Palawan, after which it is named.-Botanical history:...

is suggested in the describing paper as the next closest relative of N. gantungensis. All four species are believed to have evolved from a common ancestor that had already diverged from the lineage that would lead to the giant-pitchered N. attenboroughii
Nepenthes attenboroughii
Nepenthes attenboroughii is a montane species of insectivorous pitcher plant of the genus Nepenthes. It is named after the celebrated broadcaster and naturalist Sir David Attenborough, who is a keen enthusiast of the genus. The species is characterised by its large and distinctive bell-shaped...

and N. palawanensis
Nepenthes palawanensis
Nepenthes palawanensis is a tropical pitcher plant endemic to Sultan Peak on the island of Palawan in the Philippines, where it grows at elevations of 1100–1236 m above sea level. It was discovered in February 2010 by Jehson Cervancia and Stewart McPherson.The species appears to be most...

.

Nepenthes leonardoi
Nepenthes leonardoi
Nepenthes leonardoi is a tropical pitcher plant known from a single locality in central Palawan, the Philippines. It is closely allied to several other Palawan endemics, including N. deaniana, N. gantungensis, and N. mira. The traps of this species reach at least 24 cm in height...

, described in 2011, is another closely allied taxon. This species cannot be reliably distinguished from N. gantungensis on the basis of pitcher morphology, but may produce much darker traps, some appearing almost completely black. It also differs in having more distinctly petiolate laminae and a shorter inflorescence, with flowers that produce a characteristic musty scent.

Being the sole Nepenthes species native to the upper parts of Mount Gantung, N. gantungensis can be easily identified in the field.

External links

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