Nepenthes talangensis
Encyclopedia
Nepenthes talangensis is a tropical pitcher plant
endemic to Sumatra
, where it grows in upper montane forest at elevations of 1800–2500 m above sea level.
The specific epithet talangensis is derived from the name of Mount Talang
, to which it is endemic, and the Latin
ending -ensis, meaning "from".
during this time. The specimen series Bünnemeijer 5398 was collected on November 2, 1918, at an elevation of 2200 m. It is deposited at both Herbarium Bogoriense (BO), the herbarium
of the Bogor Botanical Gardens
, and the National Herbarium of the Netherlands
(L) in Leiden (formely Herbarium Lugduno-Batavum, the State Herbarium at Leiden), with all specimens lacking floral material. Bünnemeijer also collected Bünnemeijer 5397 on the same day at an elevation of 2400 m. It is deposited at Herbarium Bogoriense and lacks floral material.
Five days later, on November 7, Bünnemeijer 5521 (or Bünnemeijer 2552) was collected from 2500 m on Mount Talang. It is deposited at both Herbarium Bogoriense (male and female floral material) and the National Herbarium of the Netherlands (female floral material; sheet H.L.B. 822.60.920). Bünnemeijer made a fourth collection of N. talangensis from Bukit Gombak on November 16, 1918, at an elevation of 2330 m. This specimen, designated as Bünnemeijer 5748 bis (or Bünnemeijer 6740), is held at Herbarium Bogoriense and lacks floral material. It was collected on the same day as some of the earliest known specimens of N. inermis
.
on a number of occasions. In his seminal 1928 monograph, "The Nepenthaceae of the Netherlands Indies
", B. H. Danser
treated specimens of N. bongso, N. ovata
, and N. talangensis all under N. bongso. Shigeo Kurata
did the same in an article published in a 1973 issue of the The Gardens' Bulletin Singapore. Two early colour photographs of N. talangensis were published by Mike Hopkins, Ricky Maulder, and Bruce Salmon, in a 1990 issue of the Carnivorous Plant Newsletter
, where the species was again confused with, and identified as, N. bongso.
Joachim Nerz
conducted field studies of N. talangensis on Mount Talang
in 1986 and made three collections of the species: Nerz 2501 consists of a short climbing stem with pitchers and floral material; Nerz 2502 includes leaves and pitchers of the climbing stem and is preserved in alcohol
; and Nerz 2503 comprises leaves and pitchers of the rosette
. All three specimens were collected on September 6, 1986, from an elevation of 2200 m, and are deposited at the National Herbarium of the Netherlands
(L) in Leiden.
Nerz's field studies, coupled with observations of N. bongso made by Mr. and Mrs. DeWitte on Mount Singgalang
in 1993, showed that the two taxa
almost certainly represented distinct species. To confirm this and prepare a formal description, Nerz and Andreas Wistuba
examined herbarium specimens of both taxa, including Bünnemeijer 5398, 5521, and 5748 bis, as well as material of N. bongso from Mount Merapi
(Korthals s.n., the type specimen) and Mount Singgalang
(Beccari 268). This research culminated in the formal description of N. talangensis by Nerz and Wistuba in the December 1994 issue of the Carnivorous Plant Newsletter
. The authors designated Nerz 2501 as the holotype
.
Matthew Jebb
and Martin Cheek
synonymised N. talangensis with N. bongso in their 1997 monograph, "A skeletal revision of Nepenthes (Nepenthaceae)
". The authors retained N. talangensis as a probable synonym of N. bongso in their 2001 revision, "Nepenthaceae
", writing:
Nerz and Wistuba disagreed with this synonymisation. Charles Clarke
elevated N. talangensis to a species once again in his 2001 book, Nepenthes of Sumatra and Peninsular Malaysia
. The next detailed treatment of N. talangensis appeared in Stewart McPherson
's 2009 monograph, Pitcher Plants of the Old World
, which retained it as a separate species.
Despite the taxonomic confusion that has surrounded N. bongso and N. talangensis, these two species are easily distinguished by their pitchers, which are quite dissimilar.
.
, published in the journal Annals of Botany
.
is up to 0.5 cm in diameter and has internode
s up to 10 cm long that are cylindrical-angular in cross section. The stem may be branched and is yellowish-green in colour.
Leaves are coriaceous and sessile. The lamina (leaf blade) varies in shape and may be linear, lanceolate, or slightly spathulate. It measures up to 16 cm in length by 3 cm in width. The lamina has an acute or obtuse apex and an attenuate base that clasps the stem. Two to three longitudinal veins are present on either side of the midrib. Pinnate veins are irregularly reticulate. Tendril
s are up to 30 cm long. The lamina is dark green throughout, whereas the midrib and tendril are yellowish-green like the stem.
Rosette and lower pitchers are only produced briefly before the plant starts to climb. They are either entirely ovate or only ovate in the upper half and infundibular below. They often narrow just below the peristome. Terrestrial pitchers grow to 10 cm in height by 6 cm in width. A pair of fringed wings (≤10 mm wide) usually runs down the ventral surface of the trap, bearing filaments up to 8 mm long, although these wings may be absent altogether or only extend for a portion of the trap's length. The pitcher mouth is round and positioned horizontally in the front two-thirds, rising at the rear to form a short neck. The peristome
is flattened, strongly incurved, and measures up to 15 mm in width. It bears ribs up to 0.8 mm high and spaced up to 1 mm apart. These ribs terminate in distinct teeth (≤3 mm long) on the inner margin of the peristome. The peristome forms a short neck at the rear, where the teeth form two parallel rows. The inner surface is wholly glandular. The pitcher lid or operculum
is ovate to elliptic and has a cordate base. It measures up to 6 cm in length by 5 cm in width. It bears no appendages on its lower surface. A flattened spur measuring up to 5 mm in length is inserted near the base of the lid. It may or may not be branched. Lower pitchers are typically light yellow to olive green and speckled with red or purple. The inner surface is a light shade of yellow. The peristome is generally yellow or orange in freshly opened traps, later becoming dark red to purple as the pitcher matures. The upper surface of the lid is often yellow with orange to purple blotches, whereas the underside may be completely red, although this is not always the case.
Upper pitchers are either narrowly infundibular in the basal half of the pitcher cup and swollen above or infundibular throughout. A constriction is present just below the peristome. Aerial traps reach 12 cm in height by 6 cm in width. In upper pitchers, the wings may be partially developed near the pitcher mouth, or they may be reduced to ribs. The peristome reaches up to 24 mm in width and is similarly incurved to that found in terrestrial traps. Other parts of upper pitchers are similar to their lower counterparts. Upper pitchers exhibit a similar pigmentation to lower pitchers, but are typically lighter.
Nepenthes talangensis has a racemose
inflorescence
up to 14 cm long, of which the peduncle
constitutes up to 5 cm and the rachis
up to 9 cm. The peduncle has a basal diameter of 2 mm. Flowers are borne solitarily on pedicels
(≤10 mm long) with simple bract
s. Tepal
s are elliptic and up to 4 mm long. Female and male inflorescences have a similar structure.
A sparse but persistent indumentum
of simple, white hairs is present on most parts of the plant. The density of hairs on the pitchers may be so low that they appear glabrous. The laminar margins are lined with red, brown or white hairs measuring up to 3 mm.
Nepenthes talangensis varies little across its restricted range and has no infraspecific taxa.
in the Indonesia
n province
of West Sumatra
; it has been recorded from Mount Talang itself and from nearby Bukit Gombak. A population of apparently tetraploid plants is known. Although Nerz and Wistuba wrote in their formal description that N. talangensis is restricted to elevations above 2200 m, the species is now known to have a wider altitudinal distribution of 1800–2500 m.
The typical habitat of N. talangensis is mossy upper montane forest, where it is almost exclusively terrestrial, but rarely may also be found as an epiphyte
. It may grow in shady conditions under dense tree cover or among open, stunted shrubs where it is exposed to strong or even direct sunlight. At lower elevations of as little as 1800 m, N. talangensis is found in dense mossy forest, where it is sympatric with N. gymnamphora
and N. inermis
. Nepenthes talangensis is seldom sympatric with N. bongso
, despite the latter being common on Mount Talang. This is because the two species occupy distinct ecological niche
s; N. bongso is typically an epiphyte in lower montane forest, whereas N. talangensis usually grows terrestrially in upper montane forest. Natural hybrids with all three sympatric Nepenthes species have been recorded.
The conservation status
of N. talangensis is listed as Endangered
on the IUCN Red List
, based on an assessment carried out in 2000. This agrees with an informal assessment made by Charles Clarke
in 2001, who also classified the species as Endangered based on the IUCN
criteria. Since the species appears to be restricted to a single mountain, it would normally fall under the category of Critically Endangered
.
Stewart McPherson
considered the species "not seriously threatened" in his 2009 monograph, describing extant wild populations as "extensive". A substantial number of plants persist on Mount Talang despite its recent volcanic activity, which has included large eruptions. Due to its status as an active volcano, Mount Talang receives few visitors and is not a major target for development.
pitcher liquid, which coats the entire inner surfaces of the traps in a thin film. The pitchers of this species appear to function at least in part as flypaper traps, with the sticky inner walls trapping flying insects above the surface of the fluid.
Similarly viscous pitcher fluid is also found in seven other closely allied Sumatra
n species: N. aristolochioides
, N. dubia
, N. flava
, N. inermis
, N. jacquelineae
, N. jamban
, and N. tenuis
. Together with N. talangensis, these species all share infundibular pitchers that are wholly glandular or almost so.
throughout much of its botanical history, N. talangensis is clearly distinct from this species and can easily be distinguished on the basis of its greatly incurved peristome and smaller laminae with hair-fringed margins. In addition, the lower pitchers of N. bongso have a cylindrical upper portion that is non-glandular, whereas the lower traps of N. talangensis lack this cylindrical section and are wholly glandular. Furthermore, the laminar apex is acute to obtuse in N. talangensis and has a simple tendril insertion; N. bongso has a rounded apex, typically with a sub-apical tendril insertion.
The funnel-shaped upper pitchers of N. talangensis may also be reminiscent of species such as N. eymae
, N. flava
, N. inermis
, N. pitopangii
, and N. tenuis
. However, N. talangensis differs from all of these in its combination of a wide lid without appendages and a greatly incurved peristome bearing conspicuous ribs and teeth. The pitchers of N. talangensis may also resemble those of N. jamban
, but are not as broad around the mouth and have a much wider lid.
Nepenthes aristolochioides
is thought to be the closest relative of N. talangensis and these two species share a very similar lamina structure. However, they are easily separated by their pitchers; those of N. aristolochioides are uniquely dome-shaped and have an almost vertical pitcher opening.
In their formal description of N. talangensis, Nerz and Wistuba compared it with N. bongso
, N. dubia
, and N. tenuis
. The authors distinguished it from these species on the basis of the shape of the upper pitchers, the lid, and the length/width ratio of the upper pitchers. The ratio was given as 2.3 for N.talangensis; greater than that of N. tenuis (1.75) and N. dubia (1.9), but much lower than that of N. bongso (3.3).
, N. gymnamphora
, and N. inermis
.
is known to hybridise with N. talangensis on the upper slopes of Mount Talang
, where the two species grow sympatrically. Since N. talangensis was only described as a distinct species in 1994, some of the older literature identifies this hybrid as N. bongso × N. inermis.
This natural hybrid is similar to N. dubia
, but can be distinguished on the basis of several stable characters. The hybrid has a wider pitcher lid that is never relfexed beyond 90 degrees and the pitcher cup is not appressed in the lower parts as in N. dubia. In addition, the mouth of N. inermis × N. talangensis is raised towards the back as opposed to being horizontal.
Nepenthes inermis × N. talangensis has been the subject of taxonomic confusion in the past. In a 1973 article on the Nepenthes of Borneo, Singapore, and Sumatra, Shigeo Kurata
incorrectly identified specimens of this hybrid as belonging to N. dubia. In 1997, Matthew Jebb
and Martin Cheek
published their monograph "A skeletal revision of Nepenthes (Nepenthaceae)
", in which they referred to N. dubia plant material from Mount Talang
(Kurata s.n. SING). Charles Clarke
later identified Kurata s.n. as representing N. inermis × N. talangensis.
In 2001, Kurata described this hybrid as a new species, N. pyriformis. Clarke rejected this interpretation in his monograph, Nepenthes of Sumatra and Peninsular Malaysia
, published the same year. Clarke found that the type specimen of N. pyriformis, Kurata & Mikil 4230 NDC, matches the appearance of N. inermis × N. talangensis "in most respects".
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...
endemic to Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
, where it grows in upper montane forest at elevations of 1800–2500 m above sea level.
The specific epithet talangensis is derived from the name of Mount Talang
Mount Talang
Mount Talang is an active stratovolcano in West Sumatra, Indonesia. Talang has two crater lakes on its flanks, the largest of which is 1 x 2 km wide and is called Lake Talang....
, to which it is endemic, and the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
ending -ensis, meaning "from".
Early specimens
Although only recognised as a distinct species towards the end of the 20th century, N. talangensis was collected as early as 1918 by H. A. B. Bünnemeijer. Bünnemeijer made three collections from Mount TalangMount Talang
Mount Talang is an active stratovolcano in West Sumatra, Indonesia. Talang has two crater lakes on its flanks, the largest of which is 1 x 2 km wide and is called Lake Talang....
during this time. The specimen series Bünnemeijer 5398 was collected on November 2, 1918, at an elevation of 2200 m. It is deposited at both Herbarium Bogoriense (BO), 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...
of the Bogor Botanical Gardens
Bogor Botanical Gardens
The Bogor Botanical Gardens are located 60 km south of the capital of Jakarta in Bogor, Indonesia. The botanical gardens are situated in the city center of Bogor and adjoin the Istana Bogor...
, and the National Herbarium of the Netherlands
National Herbarium of the Netherlands
The National Herbarium of the Netherlands was established in 1999 through a decentralized merger of the major university herbaria of Leiden , Utrecht and Wageningen...
(L) in Leiden (formely Herbarium Lugduno-Batavum, the State Herbarium at Leiden), with all specimens lacking floral material. Bünnemeijer also collected Bünnemeijer 5397 on the same day at an elevation of 2400 m. It is deposited at Herbarium Bogoriense and lacks floral material.
Five days later, on November 7, Bünnemeijer 5521 (or Bünnemeijer 2552) was collected from 2500 m on Mount Talang. It is deposited at both Herbarium Bogoriense (male and female floral material) and the National Herbarium of the Netherlands (female floral material; sheet H.L.B. 822.60.920). Bünnemeijer made a fourth collection of N. talangensis from Bukit Gombak on November 16, 1918, at an elevation of 2330 m. This specimen, designated as Bünnemeijer 5748 bis (or Bünnemeijer 6740), is held at Herbarium Bogoriense and lacks floral material. It was collected on the same day as some of the earliest known specimens of N. inermis
Nepenthes inermis
Nepenthes inermis is a tropical pitcher plant endemic to Sumatra. The specific epithet inermis is Latin for "unarmed" and probably refers to the upper pitchers of this species, which are unique in that they completely lack a peristome....
.
Taxonomic confusion and formal description
Nepenthes talangensis has been confused with N. bongsoNepenthes bongso
Nepenthes bongso is a tropical pitcher plant endemic to Sumatra, where it has an altitudinal distribution of 1000–2700 m above sea level. The specific epithet bongso refers to the Indonesian legend of Putri Bungsu , the spirit guardian of Mount Marapi.The species was formally described by Pieter...
on a number of occasions. In his seminal 1928 monograph, "The Nepenthaceae of the Netherlands Indies
The Nepenthaceae of the Netherlands Indies
"The Nepenthaceae of the Netherlands Indies" is a seminal monograph by B. H. Danser on the tropical pitcher plants of the Dutch East Indies, North Borneo, the Malay Peninsula, and eastern New Guinea...
", B. H. Danser
B. H. Danser
Benedictus Hubertus Danser , often abbreviated B. H. Danser, was a Dutch taxonomist and botanist...
treated specimens of N. bongso, N. ovata
Nepenthes ovata
Nepenthes ovata is a tropical pitcher plant endemic to Sumatra. The specific epithet ovata is Latin for "ovate" and refers to the shape of the lower pitchers.-Botanical history:...
, and N. talangensis all under N. bongso. Shigeo Kurata
Shigeo Kurata
is a Japanese botanist and Nepenthes taxonomist whose work in the 1960s and 1970s contributed much to the current popularity of these plants. Of particular note is his 1976 guide, Nepenthes of Mount Kinabalu....
did the same in an article published in a 1973 issue of the The Gardens' Bulletin Singapore. Two early colour photographs of N. talangensis were published by Mike Hopkins, Ricky Maulder, and Bruce Salmon, in a 1990 issue of the Carnivorous Plant Newsletter
Carnivorous Plant Newsletter
The Carnivorous Plant Newsletter is the official publication of the International Carnivorous Plant Society , the largest such organization in the world.-History and editorship:...
, where the species was again confused with, and identified as, N. bongso.
Joachim Nerz
Joachim Nerz
Dr. Joachim Nerz is a taxonomist and botanist specialising in the carnivorous plant genera Heliamphora and Nepenthes. Nerz has described several new species, mostly with Andreas Wistuba.-Publications:...
conducted field studies of N. talangensis on Mount Talang
Mount Talang
Mount Talang is an active stratovolcano in West Sumatra, Indonesia. Talang has two crater lakes on its flanks, the largest of which is 1 x 2 km wide and is called Lake Talang....
in 1986 and made three collections of the species: Nerz 2501 consists of a short climbing stem with pitchers and floral material; Nerz 2502 includes leaves and pitchers of the climbing stem and is preserved in alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
; and Nerz 2503 comprises leaves and pitchers of 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:...
. All three specimens were collected on September 6, 1986, from an elevation of 2200 m, and are deposited at the National Herbarium of the Netherlands
National Herbarium of the Netherlands
The National Herbarium of the Netherlands was established in 1999 through a decentralized merger of the major university herbaria of Leiden , Utrecht and Wageningen...
(L) in Leiden.
Nerz's field studies, coupled with observations of N. bongso made by Mr. and Mrs. DeWitte on Mount Singgalang
Mount Singgalang
Singgalang is a volcano in West Sumatra, Indonesia. Its elevation is 2,877 m . It is a twin volcano with Mount Tandikat, which is located to the south-south-west of Singgalang. However, only Tandikat has had historical volcanic activity...
in 1993, showed that the two taxa
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
almost certainly represented distinct species. To confirm this and prepare a formal description, Nerz and Andreas Wistuba
Andreas Wistuba
Dr. Andreas Wistuba is a German taxonomist and botanist specialising in the carnivorous plant genera Heliamphora and Nepenthes. More than half of all known Heliamphora species have been described by Wistuba.-Publications:...
examined herbarium specimens of both taxa, including Bünnemeijer 5398, 5521, and 5748 bis, as well as material of N. bongso from Mount Merapi
Mount Merapi
Mount Merapi, Gunung Merapi , is an active stratovolcano located on the border between Central Java and Yogyakarta, Indonesia. It is the most active volcano in Indonesia and has erupted regularly since 1548...
(Korthals s.n., the type specimen) and Mount Singgalang
Mount Singgalang
Singgalang is a volcano in West Sumatra, Indonesia. Its elevation is 2,877 m . It is a twin volcano with Mount Tandikat, which is located to the south-south-west of Singgalang. However, only Tandikat has had historical volcanic activity...
(Beccari 268). This research culminated in the formal description of N. talangensis by Nerz and Wistuba in the December 1994 issue of the Carnivorous Plant Newsletter
Carnivorous Plant Newsletter
The Carnivorous Plant Newsletter is the official publication of the International Carnivorous Plant Society , the largest such organization in the world.-History and editorship:...
. The authors designated Nerz 2501 as the 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...
.
Matthew Jebb
Matthew Jebb
Dr. Matthew H. P. Jebb is an Irish taxonomist and botanist specialising in the ant plant genera Squamellaria, Myrmecodia, Hydnophytum, Myrmephytum and Anthorrhiza, as well as the carnivorous plant genus Nepenthes....
and Martin Cheek
Martin Cheek
Dr. Martin Roy Cheek is a taxonomist and botanist specialising in the carnivorous plant genus Nepenthes.-Research:Cheek has described several new Nepenthes species, mostly with Matthew Jebb, including: N. argentii, N. aristolochioides, N. danseri, N. diatas,...
synonymised N. talangensis with N. bongso in their 1997 monograph, "A skeletal revision of Nepenthes (Nepenthaceae)
A skeletal revision of Nepenthes (Nepenthaceae)
"A skeletal revision of Nepenthes " is a monograph by Matthew Jebb and Martin Cheek on the tropical pitcher plants of the genus Nepenthes. It was published in the May 1997 issue of the botanical journal Blumea. The work represented the first revision of the entire genus since John Muirhead...
". The authors retained N. talangensis as a probable synonym of N. bongso in their 2001 revision, "Nepenthaceae
Nepenthaceae (2001 monograph)
"Nepenthaceae" is a monograph by Martin Cheek and Matthew Jebb on the tropical pitcher plants of Malesia, which encompasses Brunei, Indonesia, Malaysia, Papua New Guinea, the Philippines, and Singapore. It was published in 2001 by the National Herbarium of the Netherlands as the fifteenth volume of...
", writing:
Each mountain peak in C Sumatra appears to support a slight variant of N. bongso, and we have adopted a rather broad definition of the species. Specimens from Mt Talang have been distinguished as N. talangensis, which may well merit recognition on the basis of photographs we have seen. However, we have not yet viewed the type specimens and for the meantime are leaving it as a synonym of N. bongso.
Nerz and Wistuba disagreed with this synonymisation. Charles Clarke
Charles Clarke (botanist)
Dr. Charles M. Clarke is a botanist and taxonomist specialising in the carnivorous plant genus Nepenthes. Clarke has an honours degree in Botany from Monash University in Melbourne, and a Ph.D. in Ecosystem Management at the University of New England, in Armidale, New South Wales.Clarke first...
elevated N. talangensis to a species once again in his 2001 book, Nepenthes of Sumatra and Peninsular Malaysia
Nepenthes of Sumatra and Peninsular Malaysia
Nepenthes of Sumatra and Peninsular Malaysia is a monograph by Charles Clarke on the tropical pitcher plants of Sumatra, Peninsular Malaysia, and their minor surrounding islands. It was published in 2001 by Natural History Publications...
. The next detailed treatment of N. talangensis appeared in 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....
's 2009 monograph, Pitcher Plants of the Old World
Pitcher Plants of the Old World
Pitcher Plants of the Old World is a two-volume monograph by Stewart McPherson on the pitcher plants of the genera Nepenthes and Cephalotus. It was published in May 2009 by Redfern Natural History Productions...
, which retained it as a separate species.
Despite the taxonomic confusion that has surrounded N. bongso and N. talangensis, these two species are easily distinguished by their pitchers, which are quite dissimilar.
Discovery of tetraploids
The discovery of a new population of apparently tetraploid N. talangensis was reported by Kazuhisa Mio in the July 2006 issue of the Journal of Insectivorous Plant SocietyJournal of Insectivorous Plant Society
The is a quarterly Japanese-language periodical and the official publication of the Insectivorous Plant Society of Japan. The journal was established in January 1950. As of 2010, it is published in A4 format and totals around 120 pages annually...
.
Use in research
Nepenthes talangensis was used in a 2009 study on the effect of prey capture on photosynthetic efficiencyPhotosynthetic efficiency
The photosynthetic efficiency is the fraction of light energy converted into chemical energy during photosynthesis in plants and algae. Photosynthesis can be described by the simplified chemical reactionwhere CH2O represents carbohydrates such as sugars, cellulose, and lignin.The value of the...
, published in the journal Annals of Botany
Annals of Botany
Annals of Botany is a monthly peer-reviewed scientific journal, founded in 1887, that publishes research articles, brief communications, and reviews in all areas of botany. The journal is supported and managed by Annals of Botany Company, a non-profit educational charity, and published through...
.
Description
Nepenthes talangensis is a climbing plant growing to a height of 3 m. The stemPlant 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...
is up to 0.5 cm in diameter and has internode
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...
s up to 10 cm long that are cylindrical-angular in cross section. The stem may be branched and is yellowish-green in colour.
Leaves are coriaceous and sessile. The lamina (leaf blade) varies in shape and may be linear, lanceolate, or slightly spathulate. It measures up to 16 cm in length by 3 cm in width. The lamina has an acute or obtuse apex and an attenuate base that clasps the stem. Two to three longitudinal veins are present on either side of the midrib. Pinnate veins are irregularly reticulate. 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 30 cm long. The lamina is dark green throughout, whereas the midrib and tendril are yellowish-green like the stem.
Rosette and lower pitchers are only produced briefly before the plant starts to climb. They are either entirely ovate or only ovate in the upper half and infundibular below. They often narrow just below the peristome. Terrestrial pitchers grow to 10 cm in height by 6 cm in width. A pair of fringed wings (≤10 mm wide) usually runs down the ventral surface of the trap, bearing filaments up to 8 mm long, although these wings may be absent altogether or only extend for a portion of the trap's length. The pitcher mouth is round and positioned horizontally in the front two-thirds, rising at the rear to form a short 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 flattened, strongly incurved, and measures up to 15 mm in width. It bears ribs up to 0.8 mm high and spaced up to 1 mm apart. These ribs terminate in distinct teeth (≤3 mm long) on the inner margin of the peristome. The peristome forms a short neck at the rear, where the teeth form two parallel rows. The inner surface is wholly glandular. 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 ovate to elliptic and has a cordate base. It measures up to 6 cm in length by 5 cm in width. It bears no appendages on its lower surface. A flattened spur measuring up to 5 mm in length is inserted near the base of the lid. It may or may not be branched. Lower pitchers are typically light yellow to olive green and speckled with red or purple. The inner surface is a light shade of yellow. The peristome is generally yellow or orange in freshly opened traps, later becoming dark red to purple as the pitcher matures. The upper surface of the lid is often yellow with orange to purple blotches, whereas the underside may be completely red, although this is not always the case.
Upper pitchers are either narrowly infundibular in the basal half of the pitcher cup and swollen above or infundibular throughout. A constriction is present just below the peristome. Aerial traps reach 12 cm in height by 6 cm in width. In upper pitchers, the wings may be partially developed near the pitcher mouth, or they may be reduced to ribs. The peristome reaches up to 24 mm in width and is similarly incurved to that found in terrestrial traps. Other parts of upper pitchers are similar to their lower counterparts. Upper pitchers exhibit a similar pigmentation to lower pitchers, but are typically lighter.
Nepenthes talangensis 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...
up to 14 cm long, of which the peduncle
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...
constitutes up to 5 cm and 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...
up to 9 cm. The peduncle has a basal diameter of 2 mm. Flowers are borne solitarily on 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....
(≤10 mm long) with simple bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
s. Tepal
Tepal
Tepals are elements of the perianth, or outer part of a flower, which include the petals or sepals. The term tepal is more often applied specifically when all segments of the perianth are of similar shape and color, or undifferentiated, which is called perigone...
s are elliptic and up to 4 mm long. Female and male inflorescences have a similar structure.
A sparse but persistent 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, white hairs is present on most parts of the plant. The density of hairs on the pitchers may be so low that they appear glabrous. The laminar margins are lined with red, brown or white hairs measuring up to 3 mm.
Nepenthes talangensis varies little across its restricted range and has no infraspecific taxa.
Ecology
Nepenthes talangensis is thought to be endemic to the area around Mount TalangMount Talang
Mount Talang is an active stratovolcano in West Sumatra, Indonesia. Talang has two crater lakes on its flanks, the largest of which is 1 x 2 km wide and is called Lake Talang....
in the Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
n province
Provinces of Indonesia
The province is the highest tier of local government subnational entity in Indonesia. Each province has its own local government, headed by a governor, and has its own legislative body...
of West Sumatra
West Sumatra
West Sumatra is a province of Indonesia. It lies on the west coast of the island Sumatra. It borders the provinces of North Sumatra to the north, Riau and Jambi to the east, and Bengkulu to the southeast. It includes the Mentawai Islands off the coast...
; it has been recorded from Mount Talang itself and from nearby Bukit Gombak. A population of apparently tetraploid plants is known. Although Nerz and Wistuba wrote in their formal description that N. talangensis is restricted to elevations above 2200 m, the species is now known to have a wider altitudinal distribution of 1800–2500 m.
The typical habitat of N. talangensis is mossy upper montane forest, where it is almost exclusively terrestrial, but rarely may also be found as an epiphyte
Epiphyte
An epiphyte is a plant that grows upon another plant non-parasitically or sometimes upon some other object , derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone and in the...
. It may grow in shady conditions under dense tree cover or among open, stunted shrubs where it is exposed to strong or even direct sunlight. At lower elevations of as little as 1800 m, N. talangensis is found in dense mossy forest, where it is sympatric with N. gymnamphora
Nepenthes gymnamphora
Nepenthes gymnamphora is a tropical pitcher plant native to the Indonesian islands of Java and Sumatra. There is much debate surrounding the taxonomic status of this species and the taxa N. pectinata and N. xiphioides....
and N. inermis
Nepenthes inermis
Nepenthes inermis is a tropical pitcher plant endemic to Sumatra. The specific epithet inermis is Latin for "unarmed" and probably refers to the upper pitchers of this species, which are unique in that they completely lack a peristome....
. Nepenthes talangensis is seldom sympatric with N. bongso
Nepenthes bongso
Nepenthes bongso is a tropical pitcher plant endemic to Sumatra, where it has an altitudinal distribution of 1000–2700 m above sea level. The specific epithet bongso refers to the Indonesian legend of Putri Bungsu , the spirit guardian of Mount Marapi.The species was formally described by Pieter...
, despite the latter being common on Mount Talang. This is because the two species occupy distinct ecological niche
Ecological niche
In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other; e.g. a dolphin could potentially be in another ecological niche from one that travels in a different pod if the members of these pods utilize significantly different food...
s; N. bongso is typically an epiphyte in lower montane forest, whereas N. talangensis usually grows terrestrially in upper montane forest. Natural hybrids with all three sympatric Nepenthes species 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. talangensis is listed as Endangered
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
on 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...
, based on an assessment carried out in 2000. This agrees with an informal assessment made by Charles Clarke
Charles Clarke (botanist)
Dr. Charles M. Clarke is a botanist and taxonomist specialising in the carnivorous plant genus Nepenthes. Clarke has an honours degree in Botany from Monash University in Melbourne, and a Ph.D. in Ecosystem Management at the University of New England, in Armidale, New South Wales.Clarke first...
in 2001, who also classified the species as Endangered based on the IUCN
World Conservation Union
The International Union for Conservation of Nature and Natural Resources is an international organization dedicated to finding "pragmatic solutions to our most pressing environment and development challenges." The organization publishes the IUCN Red List, compiling information from a network of...
criteria. Since the species appears to be restricted to a single mountain, it would normally fall under the category of 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....
.
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....
considered the species "not seriously threatened" in his 2009 monograph, describing extant wild populations as "extensive". A substantial number of plants persist on Mount Talang despite its recent volcanic activity, which has included large eruptions. Due to its status as an active volcano, Mount Talang receives few visitors and is not a major target for development.
Carnivory
Nepenthes talangensis produces extremely thick, mucilaginousMucilage
Mucilage is a thick, gluey substance produced by most plants and some microorganisms. It is a polar glycoprotein and an exopolysaccharide.It occurs in various parts of nearly all classes of plant, usually in relatively small percentages, and is frequently associated with other substances, such as...
pitcher liquid, which coats the entire inner surfaces of the traps in a thin film. The pitchers of this species appear to function at least in part as flypaper traps, with the sticky inner walls trapping flying insects above the surface of the fluid.
Similarly viscous pitcher fluid is also found in seven other closely allied Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
n species: N. aristolochioides
Nepenthes aristolochioides
Nepenthes aristolochioides is a tropical pitcher plant endemic to Sumatra, where it grows at elevations of 1800–2500 m above sea level. It has an extremely unusual pitcher morphology, having an almost vertical opening to its traps....
, N. dubia
Nepenthes dubia
Nepenthes dubia is a tropical pitcher plant endemic to Sumatra. The specific epithet dubia is the Latin word for "doubtful".-Botanical history:...
, N. flava
Nepenthes flava
Nepenthes flava is a tropical pitcher plant endemic to northern Sumatra, where it grows in montane forest at 1800–2200 m above sea level....
, N. inermis
Nepenthes inermis
Nepenthes inermis is a tropical pitcher plant endemic to Sumatra. The specific epithet inermis is Latin for "unarmed" and probably refers to the upper pitchers of this species, which are unique in that they completely lack a peristome....
, N. jacquelineae
Nepenthes jacquelineae
Nepenthes jacquelineae is a tropical pitcher plant endemic to Sumatra. Due to its unique pitcher morphology, it is considered to be one of the most spectacular Nepenthes species native to the island.-Botanical history:...
, N. jamban
Nepenthes jamban
Nepenthes jamban is a tropical pitcher plant endemic to northern Sumatra. The specific epithet jamban is the Indonesian word for "toilet" and refers to the shape of the pitchers.-Botanical history:...
, and N. tenuis
Nepenthes tenuis
Nepenthes tenuis is a tropical pitcher plant endemic to Sumatra. The species was first collected in 1957, from a remote mountain in the western part of the island. It remained undescribed until 1994, and was only rediscovered in the wild in 2002. Prior to this, N...
. Together with N. talangensis, these species all share infundibular pitchers that are wholly glandular or almost so.
Related species
Despite being confused with N. bongsoNepenthes bongso
Nepenthes bongso is a tropical pitcher plant endemic to Sumatra, where it has an altitudinal distribution of 1000–2700 m above sea level. The specific epithet bongso refers to the Indonesian legend of Putri Bungsu , the spirit guardian of Mount Marapi.The species was formally described by Pieter...
throughout much of its botanical history, N. talangensis is clearly distinct from this species and can easily be distinguished on the basis of its greatly incurved peristome and smaller laminae with hair-fringed margins. In addition, the lower pitchers of N. bongso have a cylindrical upper portion that is non-glandular, whereas the lower traps of N. talangensis lack this cylindrical section and are wholly glandular. Furthermore, the laminar apex is acute to obtuse in N. talangensis and has a simple tendril insertion; N. bongso has a rounded apex, typically with a sub-apical tendril insertion.
The funnel-shaped upper pitchers of N. talangensis may also be reminiscent of species such as N. eymae
Nepenthes eymae
Nepenthes eymae is a tropical pitcher plant endemic to Sulawesi, where it grows at elevations of 1000–2000 m above sea level. It is very closely related to N. maxima, from which it differs in its wine glass-shaped upper pitchers....
, N. flava
Nepenthes flava
Nepenthes flava is a tropical pitcher plant endemic to northern Sumatra, where it grows in montane forest at 1800–2200 m above sea level....
, N. inermis
Nepenthes inermis
Nepenthes inermis is a tropical pitcher plant endemic to Sumatra. The specific epithet inermis is Latin for "unarmed" and probably refers to the upper pitchers of this species, which are unique in that they completely lack a peristome....
, N. pitopangii
Nepenthes pitopangii
Nepenthes pitopangii is a tropical pitcher plant endemic to Lore Lindu National Park in Central Sulawesi, Indonesia. Only a single plant of this species is known and efforts to locate further populations on surrounding mountains have so far been unsuccessful. Nepenthes pitopangii appears to be...
, and N. tenuis
Nepenthes tenuis
Nepenthes tenuis is a tropical pitcher plant endemic to Sumatra. The species was first collected in 1957, from a remote mountain in the western part of the island. It remained undescribed until 1994, and was only rediscovered in the wild in 2002. Prior to this, N...
. However, N. talangensis differs from all of these in its combination of a wide lid without appendages and a greatly incurved peristome bearing conspicuous ribs and teeth. The pitchers of N. talangensis may also resemble those of N. jamban
Nepenthes jamban
Nepenthes jamban is a tropical pitcher plant endemic to northern Sumatra. The specific epithet jamban is the Indonesian word for "toilet" and refers to the shape of the pitchers.-Botanical history:...
, but are not as broad around the mouth and have a much wider lid.
Nepenthes aristolochioides
Nepenthes aristolochioides
Nepenthes aristolochioides is a tropical pitcher plant endemic to Sumatra, where it grows at elevations of 1800–2500 m above sea level. It has an extremely unusual pitcher morphology, having an almost vertical opening to its traps....
is thought to be the closest relative of N. talangensis and these two species share a very similar lamina structure. However, they are easily separated by their pitchers; those of N. aristolochioides are uniquely dome-shaped and have an almost vertical pitcher opening.
In their formal description of N. talangensis, Nerz and Wistuba compared it with N. bongso
Nepenthes bongso
Nepenthes bongso is a tropical pitcher plant endemic to Sumatra, where it has an altitudinal distribution of 1000–2700 m above sea level. The specific epithet bongso refers to the Indonesian legend of Putri Bungsu , the spirit guardian of Mount Marapi.The species was formally described by Pieter...
, N. dubia
Nepenthes dubia
Nepenthes dubia is a tropical pitcher plant endemic to Sumatra. The specific epithet dubia is the Latin word for "doubtful".-Botanical history:...
, and N. tenuis
Nepenthes tenuis
Nepenthes tenuis is a tropical pitcher plant endemic to Sumatra. The species was first collected in 1957, from a remote mountain in the western part of the island. It remained undescribed until 1994, and was only rediscovered in the wild in 2002. Prior to this, N...
. The authors distinguished it from these species on the basis of the shape of the upper pitchers, the lid, and the length/width ratio of the upper pitchers. The ratio was given as 2.3 for N.talangensis; greater than that of N. tenuis (1.75) and N. dubia (1.9), but much lower than that of N. bongso (3.3).
Natural hybrids
Three natural hybrids involving N. talangensis have been recorded: with N. bongsoNepenthes bongso
Nepenthes bongso is a tropical pitcher plant endemic to Sumatra, where it has an altitudinal distribution of 1000–2700 m above sea level. The specific epithet bongso refers to the Indonesian legend of Putri Bungsu , the spirit guardian of Mount Marapi.The species was formally described by Pieter...
, N. gymnamphora
Nepenthes gymnamphora
Nepenthes gymnamphora is a tropical pitcher plant native to the Indonesian islands of Java and Sumatra. There is much debate surrounding the taxonomic status of this species and the taxa N. pectinata and N. xiphioides....
, and N. inermis
Nepenthes inermis
Nepenthes inermis is a tropical pitcher plant endemic to Sumatra. The specific epithet inermis is Latin for "unarmed" and probably refers to the upper pitchers of this species, which are unique in that they completely lack a peristome....
.
Nepenthes × pyriformis
Nepenthes inermisNepenthes inermis
Nepenthes inermis is a tropical pitcher plant endemic to Sumatra. The specific epithet inermis is Latin for "unarmed" and probably refers to the upper pitchers of this species, which are unique in that they completely lack a peristome....
is known to hybridise with N. talangensis on the upper slopes of Mount Talang
Mount Talang
Mount Talang is an active stratovolcano in West Sumatra, Indonesia. Talang has two crater lakes on its flanks, the largest of which is 1 x 2 km wide and is called Lake Talang....
, where the two species grow sympatrically. Since N. talangensis was only described as a distinct species in 1994, some of the older literature identifies this hybrid as N. bongso × N. inermis.
This natural hybrid is similar to N. dubia
Nepenthes dubia
Nepenthes dubia is a tropical pitcher plant endemic to Sumatra. The specific epithet dubia is the Latin word for "doubtful".-Botanical history:...
, but can be distinguished on the basis of several stable characters. The hybrid has a wider pitcher lid that is never relfexed beyond 90 degrees and the pitcher cup is not appressed in the lower parts as in N. dubia. In addition, the mouth of N. inermis × N. talangensis is raised towards the back as opposed to being horizontal.
Nepenthes inermis × N. talangensis has been the subject of taxonomic confusion in the past. In a 1973 article on the Nepenthes of Borneo, Singapore, and Sumatra, Shigeo Kurata
Shigeo Kurata
is a Japanese botanist and Nepenthes taxonomist whose work in the 1960s and 1970s contributed much to the current popularity of these plants. Of particular note is his 1976 guide, Nepenthes of Mount Kinabalu....
incorrectly identified specimens of this hybrid as belonging to N. dubia. In 1997, Matthew Jebb
Matthew Jebb
Dr. Matthew H. P. Jebb is an Irish taxonomist and botanist specialising in the ant plant genera Squamellaria, Myrmecodia, Hydnophytum, Myrmephytum and Anthorrhiza, as well as the carnivorous plant genus Nepenthes....
and Martin Cheek
Martin Cheek
Dr. Martin Roy Cheek is a taxonomist and botanist specialising in the carnivorous plant genus Nepenthes.-Research:Cheek has described several new Nepenthes species, mostly with Matthew Jebb, including: N. argentii, N. aristolochioides, N. danseri, N. diatas,...
published their monograph "A skeletal revision of Nepenthes (Nepenthaceae)
A skeletal revision of Nepenthes (Nepenthaceae)
"A skeletal revision of Nepenthes " is a monograph by Matthew Jebb and Martin Cheek on the tropical pitcher plants of the genus Nepenthes. It was published in the May 1997 issue of the botanical journal Blumea. The work represented the first revision of the entire genus since John Muirhead...
", in which they referred to N. dubia plant material from Mount Talang
Mount Talang
Mount Talang is an active stratovolcano in West Sumatra, Indonesia. Talang has two crater lakes on its flanks, the largest of which is 1 x 2 km wide and is called Lake Talang....
(Kurata s.n. SING). Charles Clarke
Charles Clarke (botanist)
Dr. Charles M. Clarke is a botanist and taxonomist specialising in the carnivorous plant genus Nepenthes. Clarke has an honours degree in Botany from Monash University in Melbourne, and a Ph.D. in Ecosystem Management at the University of New England, in Armidale, New South Wales.Clarke first...
later identified Kurata s.n. as representing N. inermis × N. talangensis.
In 2001, Kurata described this hybrid as a new species, N. pyriformis. Clarke rejected this interpretation in his monograph, Nepenthes of Sumatra and Peninsular Malaysia
Nepenthes of Sumatra and Peninsular Malaysia
Nepenthes of Sumatra and Peninsular Malaysia is a monograph by Charles Clarke on the tropical pitcher plants of Sumatra, Peninsular Malaysia, and their minor surrounding islands. It was published in 2001 by Natural History Publications...
, published the same year. Clarke found that the type specimen of N. pyriformis, Kurata & Mikil 4230 NDC, matches the appearance of N. inermis × N. talangensis "in most respects".