Nepenthes eymae
Encyclopedia
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.
The specific epithet eymae honours Pierre Joseph Eyma
, a Dutch
botanist who worked extensively in the Dutch East Indies
and who originally discovered the species.
by Dutch botanist Pierre Joseph Eyma
in 1938. Eyma's original material of this species includes the herbarium
specimen Eyma 3968, which bears a male inflorescence
.
Nepenthes eymae was formally described
by Shigeo Kurata
in a 1984 issue of the Journal of Insectivorous Plant Society
. The holotype
, designated as Kurata, Atsumi & Komatsu 102a, was collected on the northern spur of Mount Lumut in Central Sulawesi
, at an altitude of 1850 m, on November 5, 1983. A series of isotype
s (Kurata, Atsumi & Komatsu 103, 104, and 105) was also listed by Kurata. The repository of these four specimens is not indicated in the type description and they have not been located, but if they were deposited in a public institution this is likely to have been the herbarium of the Nippon Dental College (NDC). Despite this, the species name is valid per Article 37 of the International Code of Botanical Nomenclature, and Kurata's description includes an illustration of the holotype on page 44. Kurata published the species with the specific epithet eymai, honouring Pierre Joseph Eyma
. Other authors later noted that although Eyma was male, the name is feminine, and so the epithet was emended to eymae.
Almost concurrently with Kurata's publication, John Turnbull and Anne Middleton described the same species under the name N. infundibuliformis in the journal Reinwardtia. Kurata's description was published on February 6, whereas Turnbull and Middleton's was printed four days later, on February 10. As such, the name N. eymae holds nomenclatural priority and N. infundibuliformis is considered a heterotypic synonym. A similar situation involved the descriptions of N. glabrata
and N. hamata
by the same authors. Turnbull and Middleton's description is based on the specimen J.R.Turnbull & A.T.Middleton 83148a, which was collected by the authors on September 20, 1983, from Mount Lumut Kecil in Sulawesi at the coordinates 1°03′S 121°41′E, at an altitude of 1500 m. In their description of the species, Turnbull and Middleton stated that the type material was deposited at Herbarium Bogoriense (BO), the herbarium of the Bogor Botanical Gardens
, but Matthew Jebb
and Martin Cheek
were unable to locate it and wrote that it "appear[s] not to have been deposited at Bogor as stated". In addition to the herbarium specimens of N. eymae mentioned here, a number of others have appeared in the literature.
Most authors regard N. eymae as a distinct species and it has been treated as such in all major monographs on the genus, including Matthew Jebb
and Martin Cheek
's "A skeletal revision of Nepenthes (Nepenthaceae)
" (1997) and "Nepenthaceae
" (2001), as well as Stewart McPherson
's Pitcher Plants of the Old World
(2009). Nonetheless, some authors have expressed doubt that it merits distinction from N. maxima
at the species level. In Pitcher Plants of the Old World, McPherson wrote that "the specific status of N. eymae seems warranted since the two taxa [N. eymae and N. maxima] appear to occur both together and in isolated, self-sustaining communities".
s, which are found 3–10 mm above the leaf axils in climbing stems, are spike-like and measure up to 10 mm (rarely 20 mm) in length by 1.5 mm in width.
Leaves are coriaceous and petiolate. The lamina (leaf blade) is oblong or oblong-elliptic and reaches up to 35 cm in length by 12 cm in width. The laminar apex is rounded or acute to obtuse and is not peltate. The base is obtuse and attenuate, narrowing to form a petiole
. The petiole is canaliculate and occasionally winged, the wings being around 4 mm wide. The petiole may be up to 18 cm long in etiolated
plants, but is more typically up to 10 cm long. It clasps the stem for around half of its circumference and is abruptly decurrent, sending off a pair of low ridges to the node below. Longitudinal and pinnate veins are inconspicuous.
Rosette and lower pitchers are generally ovate throughout, but may also be cylindrical. They are often slightly constricted below the pitcher orifice. Mature lower pitchers are the largest traps produced by the plant, growing to 24 cm in height by 16 cm in width. A pair of wings (≤2 cm wide) is present on the ventral surface of the pitcher cup; the fringe elements are up to 8 mm long. The rear of the pitcher is elongated into a pronounced neck. The pitcher mouth is ovate and concave, and has an oblique insertion. The peristome
is glossy and more-or-less cylindrical in cross section. It is up to 2 cm wide at the front, becoming expanded at the sides and rear, where it reaches a maximum width of over 5 cm. The outer margin of the peristome may be sinuate, whereas the inner margin is deeply incurved, especially towards the back of the pitcher. The two lobes of the peristome are typically separated by a gap of several millimetres under the lid. The peristome ribs are well developed, being up to 2 mm high. The pitcher lid or operculum
is ovate to triangular, growing to 5 cm in length by 3 cm in width. It has an acuminate apex and a truncate to auriculate base. The lid is noted for commonly exhibiting irregular, highly crenellated margins. Two prominent appendages are often found on the lid's lower surface. The first, a triangular basal crest, is up to 12 mm long. The second, a filiform or triangular apical appendage, is up to 18 mm long. Both the appendages and the lid's midline bear elliptic, bordered glands measuring up to 2 mm by 1 mm. The remainder of the lid's lower surface bears many smaller glands. An unbranched spur up to 10 mm long is inserted near the base of the lid.
Upper pitchers are narrowly infundibular in the basal half to three-quarters, rapidly expanding to become broadly infundibular in the upper portion. They may be shortly contracted directly below the orifice. Upper pitchers are significantly smaller than their terrestrial counterparts, reaching only 15 cm in height by 8 cm in width. Characteristically, the hollow pitcher tube continues past the curved basal portion of the trap and for a few centimetres up the tendril. This is also commonly seen in N. flava
, N. fusca
, N. jamban
, N. ovata
, and N. vogelii
. The wings are often reduced to ridges, although no vestige of the wings may be apparent in some specimens. These ridges typically run parallel in the lower part of the pitcher, becoming divergent above. The pitcher mouth is horizontal and straight. The peristome is flattened, glossy and up to 1.5 cm wide, being of approximately equal width across its span or broader towards the rear. The peristome ribs are highly reduced but conspicuous, being only up to 0.5 mm high and spaced up to 0.5 mm apart. The rear of the pitcher is elongated into an acuminate neck (≤3 cm long) that may be vertical or inclined forwards at a considerable angle relative to the pitcher orifice. The peristome's inner margin lacks teeth, while the outer margin is often sinuate at the base of the neck. The lid is typically hastate and very narrow, measuring up to 8 cm in length, with basal and middle widths of up to 2.5 and 1 cm, respectively. It bears rounded basal lobes and an obtuse to abruptly rounded apex. It is often curled upwards and may be crenellated at the margins. The presence of appendages is variable in upper pitchers: the lid may possess a pair of appendages as in terrestrial pitchers or may lack them completely. Where these appendages are present, the basal one is hook-shaped and up to 8 mm long and the apical one filiform and up to 12 mm long. The glands of the lower lid surface are similar to those found in lower pitchers. The spur is inserted 10 mm below the lid. It may be simple or bifid at its apex, and measures up to 10 mm in length. Developing pitchers have laterally appressed walls and a pronounced bulge at the rear, which holds the spur upright. The spur has a closed bifurcation at this point.
Nepenthes eymae has a racemose
inflorescence
. The male inflorescence measures up to 30 cm in length by 2.5 cm in width (flowers included), of which the peduncle
(≤3 mm wide at its base) constitutes up to 11 cm and the rachis
up to 20 cm. Flowers are borne singly or in pairs, the two-flowered partial peduncles being located towards the base of the inflorescence. The partial peduncles are ebracteate and number 30–40. They are approximately 4 mm long, being formed from a pair of basally-united pedicels
around 10 mm long. Tepal
s are elliptic and around 4 mm long by 2 mm wide. The androphore is around 4 mm long and bears an anther head measuring 1 mm by 1.5 mm.
An indumentum
of soft, orange to reddish-brown hairs is often present on all mature vegetative parts, including the stem, lower lid surface, and laminar surfaces. This covering consists of tufted hairs up to 0.05 mm long and simple hairs typically up to 0.8 mm long (those of the tendril, midrib, lid and spur are denser and longer, reaching 2 mm). However, the indumentum is variable and may be reduced to the point of being completely inconspicuous in some populations.
The stem and midribs are yellowish-green, and the laminae dark green. The tendrils may be yellow to green or tinged red. In terrestrial traps, the pitcher cups may be white, green, yellow, brown, or red, and are often red speckled. Traps bearing a conspicuous indumentum may have a maroon sheen under certain light conditions. The inner surface ranges from yellow or olive green to almost brown, and commonly has darker blotches of red, brown, or purple. The peristome is usually dark, from reddish-brown to black throughout in older specimens. It frequently bears stripes ranging from yellow to black. The operculum is green to brown and often mottled with red to black markings on its lower surface. Upper pitcher are predominantly yellow, sometimes bearing red to purple flecks on the inner surface and lid underside. The appearance of the peristome is variable: it may be a solid orange to red (in which case it is often darker towards the inner edge), or it may be narrowly streaked with red, brown, purple, or black. Tepal
s are red.
No infraspecific taxa of N. eymae have been described.
n island of Sulawesi
. It has been recorded from the provinces
of Central Sulawesi
(including the East Peninsula
) and West Sulawesi
. Many of the peaks in these regions are poorly known and may support as-yet undiscovered populations of N. eymae. The species has a wide altitudinal distribution of 1000 to at least 2000 m above sea level, typically being found above 1400 m.
The species generally grows terrestrially, but may also be epiphytic
at higher elevations. It has been recorded from a wide variety of habitats, including heath forest
, river banks, exposed sites such as cliff faces and landslides, and disturbed or recovering secondary vegetation (such as previously logged dipterocarp forest). Towards the upper end of its altitudinal range, N. eymae is found among the ridge and summit vegetation of upper montane forest. The species occurs in both shaded and exposed sites, but grows best in the latter. Nepenthes eymae has no confirmed natural hybrids, although introgression
may take place where this species is sympatric with N. maxima
.
The conservation status
of N. eymae is listed as Vulnerable
on the IUCN Red List
, based on an assessment carried out in 2000. In 2009, Stewart McPherson
wrote that the species is "widespread and locally abundant" across its range and that most populations are "remote and not seriously threatened at present". Nepenthes eymae is known to occur in one protected area
(Morowali Nature Reserve), although the full extent of its range is unknown.
pitcher fluid that coats the entire inner surface of the traps in a thin film. This is seen in cultivated plants as well and is most prominent in upper pitchers, which must contend with the action of the wind. These pitchers appear to function at least in part as flypaper traps, with the sticky inner walls trapping small flying insects above the surface of the fluid. The prey then gradually slide down into the base of the pitcher where they are digested. This trapping method was noted by Peter D'Amato
in 1993, who observed that, in cultivated plants, lower pitchers were more successful at catching ants than were upper pitchers.
A 2011 study that used cultivated material of N. eymae recorded a mean digestive fluid relaxation time of 0.096 seconds (± 0.000) for this species. As for the majority of studied highland Nepenthes (but not lowlanders), this value differed significantly (P < 0.001
) from that of distilled water, leading the authors to categorise N. eymae as a viscoelastic
species.
Similarly viscous pitcher fluid is found in the group of closely allied Sumatra
n species that includes N. aristolochioides
, N. dubia
, N. flava
, N. inermis
, N. jacquelineae
, N. jamban
, N. talangensis
, and N. tenuis
. These species all share infundibular pitchers.
, which is widespread across Sulawesi
, New Guinea
, and the Maluku Islands
. It differs from this species in its wingless, infundibular and relatively small upper pitchers, ovate lower pitchers, and hastate lid. While some forms of N. maxima also produce entirely infundibular aerial traps, these are not usually as abruptly contracted (and therefore wine glass
-shaped) as in N. eymae, and may or may not have fringed wings. Where the two species grow side-by-side, introgression
may blur these morphological boundaries and make circumscription difficult. Like N. eymae, N. maxima and N. klossii
(another closely related species) also commonly have two lid appendages.
Nepenthes fusca
of Borneo
may produce aerial pitchers resembling those of N. eymae, although its lower pitchers are considerably narrower and cylindrical in shape. The lower pitchers of N. eymae could potentially be confused with those of another Bornean endemic, N. veitchii
, although otherwise these species have little in common, particularly with respect to the upper pitchers.
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 Sulawesi
Sulawesi
Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands. In Indonesia, only Sumatra, Borneo, and Papua are larger in territory, and only Java and Sumatra have larger Indonesian populations.- Etymology :The Portuguese were the first to...
, where it grows at elevations of 1000–2000 m above sea level. It is very closely related to N. maxima
Nepenthes maxima
Nepenthes maxima , the Great Pitcher-Plant, is a carnivorous pitcher plant species of the genus Nepenthes. It has a relatively wide distribution covering Sulawesi, New Guinea, and the Maluku Islands. It is closely related to N. eymae....
, from which it differs in its wine glass
Wine glass
A wine glass is a type of glass stemware that is used to drink and taste wine. It is generally composed of three parts: the bowl, stem, and foot...
-shaped upper pitchers.
The specific epithet eymae honours Pierre Joseph Eyma
Pierre Joseph Eyma
Pierre Joseph Eyma was a Dutch botanist.Eyma was born in Maarssen, the Netherlands, in 1903. He studied at Utrecht University and served as an assistant at the university's herbarium between 1929 and 1937. Eyma earned a doctorate in 1932 for a taxonomic thesis on Surinamese plants...
, a Dutch
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
botanist who worked extensively in the Dutch East Indies
Dutch East Indies
The Dutch East Indies was a Dutch colony that became modern Indonesia following World War II. It was formed from the nationalised colonies of the Dutch East India Company, which came under the administration of the Netherlands government in 1800....
and who originally discovered the species.
Botanical history
Nepenthes eymae was discovered in central SulawesiSulawesi
Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands. In Indonesia, only Sumatra, Borneo, and Papua are larger in territory, and only Java and Sumatra have larger Indonesian populations.- Etymology :The Portuguese were the first to...
by Dutch botanist Pierre Joseph Eyma
Pierre Joseph Eyma
Pierre Joseph Eyma was a Dutch botanist.Eyma was born in Maarssen, the Netherlands, in 1903. He studied at Utrecht University and served as an assistant at the university's herbarium between 1929 and 1937. Eyma earned a doctorate in 1932 for a taxonomic thesis on Surinamese plants...
in 1938. Eyma's original material of this species includes 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 Eyma 3968, which bears a male 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...
.
Nepenthes eymae 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 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....
in a 1984 issue of the Journal of Insectivorous Plant Society
Journal 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...
. 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...
, designated as Kurata, Atsumi & Komatsu 102a, was collected on the northern spur of Mount Lumut in Central Sulawesi
Central Sulawesi
Central Sulawesi is a province of Indonesia located in the centre of Sulawesi. It was established on 13 April 1964....
, at an altitude of 1850 m, on November 5, 1983. A series of isotype
Isotype
Isotype can refer to:* In crystallography, an "isotype" is a synonym for isomorph* In biology, per the International Code of Botanical Nomenclature, the "isotype" is a duplicate of the holotype....
s (Kurata, Atsumi & Komatsu 103, 104, and 105) was also listed by Kurata. The repository of these four specimens is not indicated in the type description and they have not been located, but if they were deposited in a public institution this is likely to have been the herbarium of the Nippon Dental College (NDC). Despite this, the species name is valid per Article 37 of the International Code of Botanical Nomenclature, and Kurata's description includes an illustration of the holotype on page 44. Kurata published the species with the specific epithet eymai, honouring Pierre Joseph Eyma
Pierre Joseph Eyma
Pierre Joseph Eyma was a Dutch botanist.Eyma was born in Maarssen, the Netherlands, in 1903. He studied at Utrecht University and served as an assistant at the university's herbarium between 1929 and 1937. Eyma earned a doctorate in 1932 for a taxonomic thesis on Surinamese plants...
. Other authors later noted that although Eyma was male, the name is feminine, and so the epithet was emended to eymae.
Almost concurrently with Kurata's publication, John Turnbull and Anne Middleton described the same species under the name N. infundibuliformis in the journal Reinwardtia. Kurata's description was published on February 6, whereas Turnbull and Middleton's was printed four days later, on February 10. As such, the name N. eymae holds nomenclatural priority and N. infundibuliformis is considered a heterotypic synonym. A similar situation involved the descriptions of N. glabrata
Nepenthes glabrata
Nepenthes glabrata is a tropical pitcher plant endemic to Sulawesi. The species grows in open, high forest at elevations of 1600 to 2100 m. It produces dainty, colourful pitchers reaching only a few centimetres in height...
and N. hamata
Nepenthes hamata
Nepenthes hamata is a tropical pitcher plant endemic to Sulawesi, where it grows at elevations of 1400–2500 m above sea level.The specific epithet hamata is derived from the Latin word hamatus, meaning "hooked"...
by the same authors. Turnbull and Middleton's description is based on the specimen J.R.Turnbull & A.T.Middleton 83148a, which was collected by the authors on September 20, 1983, from Mount Lumut Kecil in Sulawesi at the coordinates 1°03′S 121°41′E, at an altitude of 1500 m. In their description of the species, Turnbull and Middleton stated that the type material was deposited at Herbarium Bogoriense (BO), the herbarium 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...
, but 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,...
were unable to locate it and wrote that it "appear[s] not to have been deposited at Bogor as stated". In addition to the herbarium specimens of N. eymae mentioned here, a number of others have appeared in the literature.
Most authors regard N. eymae as a distinct species and it has been treated as such in all major monographs on the genus, including 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,...
's "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...
" (1997) and "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...
" (2001), as well as 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 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...
(2009). Nonetheless, some authors have expressed doubt that it merits distinction from N. maxima
Nepenthes maxima
Nepenthes maxima , the Great Pitcher-Plant, is a carnivorous pitcher plant species of the genus Nepenthes. It has a relatively wide distribution covering Sulawesi, New Guinea, and the Maluku Islands. It is closely related to N. eymae....
at the species level. In Pitcher Plants of the Old World, McPherson wrote that "the specific status of N. eymae seems warranted since the two taxa [N. eymae and N. maxima] appear to occur both together and in isolated, self-sustaining communities".
Description
Nepenthes eymae is a climbing plant growing to a height of up to 8 m. The stem, which may be branched, is two-ridged and up to 8 mm in diameter. Internodes are up to 6 cm long. Axillary budAxillary bud
The axillary bud is an embryonic shoot which lies at the junction of the stem and petiole of a plant.As the apical meristem grows and forms leaves, a region of meristematic cells are left behind at the node between the stem and the leaf. These axillary buds are usually dormant, inibited by auxin...
s, which are found 3–10 mm above the leaf axils in climbing stems, are spike-like and measure up to 10 mm (rarely 20 mm) in length by 1.5 mm in width.
Leaves are coriaceous and petiolate. The lamina (leaf blade) is oblong or oblong-elliptic and reaches up to 35 cm in length by 12 cm in width. The laminar apex is rounded or acute to obtuse and is not peltate. The base is obtuse and attenuate, narrowing to form a petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
. The petiole is canaliculate and occasionally winged, the wings being around 4 mm wide. The petiole may be up to 18 cm long in 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...
plants, but is more typically up to 10 cm long. It clasps the stem for around half of its circumference and is abruptly decurrent, sending off a pair of low ridges to the node below. Longitudinal and pinnate veins are inconspicuous.
Rosette and lower pitchers are generally ovate throughout, but may also be cylindrical. They are often slightly constricted below the pitcher orifice. Mature lower pitchers are the largest traps produced by the plant, growing to 24 cm in height by 16 cm in width. A pair of wings (≤2 cm wide) is present on the ventral surface of the pitcher cup; the fringe elements are up to 8 mm long. The rear of the pitcher is elongated into a pronounced neck. The pitcher mouth is ovate and concave, and has an oblique insertion. 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 glossy and more-or-less cylindrical in cross section. It is up to 2 cm wide at the front, becoming expanded at the sides and rear, where it reaches a maximum width of over 5 cm. The outer margin of the peristome may be sinuate, whereas the inner margin is deeply incurved, especially towards the back of the pitcher. The two lobes of the peristome are typically separated by a gap of several millimetres under the lid. The peristome ribs are well developed, being up to 2 mm high. 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 triangular, growing to 5 cm in length by 3 cm in width. It has an acuminate apex and a truncate to auriculate base. The lid is noted for commonly exhibiting irregular, highly crenellated margins. Two prominent appendages are often found on the lid's lower surface. The first, a triangular basal crest, is up to 12 mm long. The second, a filiform or triangular apical appendage, is up to 18 mm long. Both the appendages and the lid's midline bear elliptic, bordered glands measuring up to 2 mm by 1 mm. The remainder of the lid's lower surface bears many smaller glands. An unbranched spur up to 10 mm long is inserted near the base of the lid.
Upper pitchers are narrowly infundibular in the basal half to three-quarters, rapidly expanding to become broadly infundibular in the upper portion. They may be shortly contracted directly below the orifice. Upper pitchers are significantly smaller than their terrestrial counterparts, reaching only 15 cm in height by 8 cm in width. Characteristically, the hollow pitcher tube continues past the curved basal portion of the trap and for a few centimetres up the tendril. This is also commonly seen in 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. fusca
Nepenthes fusca
Nepenthes fusca , or the Dusky Pitcher-Plant, is a tropical pitcher plant endemic to Borneo. It is found throughout a wide altitudinal range and is almost always epiphytic in nature, primarily growing in mossy forest....
, 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:...
, 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. vogelii
Nepenthes vogelii
Nepenthes vogelii is a tropical pitcher plant endemic to Borneo. It is thought to be most closely related to N. fusca.-Botanical history:...
. The wings are often reduced to ridges, although no vestige of the wings may be apparent in some specimens. These ridges typically run parallel in the lower part of the pitcher, becoming divergent above. The pitcher mouth is horizontal and straight. The peristome is flattened, glossy and up to 1.5 cm wide, being of approximately equal width across its span or broader towards the rear. The peristome ribs are highly reduced but conspicuous, being only up to 0.5 mm high and spaced up to 0.5 mm apart. The rear of the pitcher is elongated into an acuminate neck (≤3 cm long) that may be vertical or inclined forwards at a considerable angle relative to the pitcher orifice. The peristome's inner margin lacks teeth, while the outer margin is often sinuate at the base of the neck. The lid is typically hastate and very narrow, measuring up to 8 cm in length, with basal and middle widths of up to 2.5 and 1 cm, respectively. It bears rounded basal lobes and an obtuse to abruptly rounded apex. It is often curled upwards and may be crenellated at the margins. The presence of appendages is variable in upper pitchers: the lid may possess a pair of appendages as in terrestrial pitchers or may lack them completely. Where these appendages are present, the basal one is hook-shaped and up to 8 mm long and the apical one filiform and up to 12 mm long. The glands of the lower lid surface are similar to those found in lower pitchers. The spur is inserted 10 mm below the lid. It may be simple or bifid at its apex, and measures up to 10 mm in length. Developing pitchers have laterally appressed walls and a pronounced bulge at the rear, which holds the spur upright. The spur has a closed bifurcation at this point.
Nepenthes eymae 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...
. The male inflorescence measures up to 30 cm in length by 2.5 cm in width (flowers included), 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...
(≤3 mm wide at its base) constitutes up to 11 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 20 cm. Flowers are borne singly or in pairs, the two-flowered partial peduncles being located towards the base of the inflorescence. The partial peduncles are ebracteate and number 30–40. They are approximately 4 mm long, being formed from a pair of basally-united 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....
around 10 mm long. 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 around 4 mm long by 2 mm wide. The androphore is around 4 mm long and bears an anther head measuring 1 mm by 1.5 mm.
An 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 soft, orange to reddish-brown hairs is often present on all mature vegetative parts, including the stem, lower lid surface, and laminar surfaces. This covering consists of tufted hairs up to 0.05 mm long and simple hairs typically up to 0.8 mm long (those of the tendril, midrib, lid and spur are denser and longer, reaching 2 mm). However, the indumentum is variable and may be reduced to the point of being completely inconspicuous in some populations.
The stem and midribs are yellowish-green, and the laminae dark green. The tendrils may be yellow to green or tinged red. In terrestrial traps, the pitcher cups may be white, green, yellow, brown, or red, and are often red speckled. Traps bearing a conspicuous indumentum may have a maroon sheen under certain light conditions. The inner surface ranges from yellow or olive green to almost brown, and commonly has darker blotches of red, brown, or purple. The peristome is usually dark, from reddish-brown to black throughout in older specimens. It frequently bears stripes ranging from yellow to black. The operculum is green to brown and often mottled with red to black markings on its lower surface. Upper pitcher are predominantly yellow, sometimes bearing red to purple flecks on the inner surface and lid underside. The appearance of the peristome is variable: it may be a solid orange to red (in which case it is often darker towards the inner edge), or it may be narrowly streaked with red, brown, purple, or black. 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 red.
No infraspecific taxa of N. eymae have been described.
Ecology
Nepenthes eymae is endemic to the IndonesiaIndonesia
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 island of Sulawesi
Sulawesi
Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands. In Indonesia, only Sumatra, Borneo, and Papua are larger in territory, and only Java and Sumatra have larger Indonesian populations.- Etymology :The Portuguese were the first to...
. It has been recorded from the provinces
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 Central Sulawesi
Central Sulawesi
Central Sulawesi is a province of Indonesia located in the centre of Sulawesi. It was established on 13 April 1964....
(including the East Peninsula
East Peninsula, Sulawesi
The East Peninsula is one of the four principal peninsulas on the island of Sulawesi.It stretches east from the central part of the island, forming the southern boundary of the Gulf of Tomini....
) and West Sulawesi
West Sulawesi
West Sulawesi is a province of Indonesia, which was created in 2004.- Geography :It is on the island of Sulawesi and includes the regencies of Polewali Mandar, Mamasa, Majene, Mamuju, and Mamuju Utara, which were formerly part of South Sulawesi...
. Many of the peaks in these regions are poorly known and may support as-yet undiscovered populations of N. eymae. The species has a wide altitudinal distribution of 1000 to at least 2000 m above sea level, typically being found above 1400 m.
The species generally grows terrestrially, but may also be epiphytic
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...
at higher elevations. It has been recorded from a wide variety of habitats, including heath forest
Heath forest
Heath forest is a type of tropical moist forest found in areas with acidic, sandy soils that are extremely nutrient-poor. Notable examples are the Rio Negro campinarana of the Amazon Basin in South America, and the Sundaland heath forests of Borneo and neighboring islands.-External links:**...
, river banks, exposed sites such as cliff faces and landslides, and disturbed or recovering secondary vegetation (such as previously logged dipterocarp forest). Towards the upper end of its altitudinal range, N. eymae is found among the ridge and summit vegetation of upper montane forest. The species occurs in both shaded and exposed sites, but grows best in the latter. Nepenthes eymae has no confirmed natural hybrids, although introgression
Introgression
Introgression, also known as introgressive hybridization, in genetics is the movement of a gene from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species...
may take place where this species is sympatric with N. maxima
Nepenthes maxima
Nepenthes maxima , the Great Pitcher-Plant, is a carnivorous pitcher plant species of the genus Nepenthes. It has a relatively wide distribution covering Sulawesi, New Guinea, and the Maluku Islands. It is closely related to N. eymae....
.
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. eymae is listed as Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
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. In 2009, 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....
wrote that the species is "widespread and locally abundant" across its range and that most populations are "remote and not seriously threatened at present". Nepenthes eymae is known to occur in one protected area
Protected area
Protected areas are locations which receive protection because of their recognised natural, ecological and/or cultural values. There are several kinds of protected areas, which vary by level of protection depending on the enabling laws of each country or the regulations of the international...
(Morowali Nature Reserve), although the full extent of its range is unknown.
Carnivory
Nepenthes eymae produces an 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 fluid that coats the entire inner surface of the traps in a thin film. This is seen in cultivated plants as well and is most prominent in upper pitchers, which must contend with the action of the wind. These pitchers appear to function at least in part as flypaper traps, with the sticky inner walls trapping small flying insects above the surface of the fluid. The prey then gradually slide down into the base of the pitcher where they are digested. This trapping method was noted by Peter D'Amato
Peter D'Amato
Peter D'Amato is an American author, businessman, and carnivorous plant authority. He is the owner of California Carnivores, the largest nursery of carnivorous plants in the world, and the author of The Savage Garden , a book on the cultivation of insectivorous plants...
in 1993, who observed that, in cultivated plants, lower pitchers were more successful at catching ants than were upper pitchers.
A 2011 study that used cultivated material of N. eymae recorded a mean digestive fluid relaxation time of 0.096 seconds (± 0.000) for this species. As for the majority of studied highland Nepenthes (but not lowlanders), this value differed significantly (P < 0.001
P-value
In statistical significance testing, the p-value is the probability of obtaining a test statistic at least as extreme as the one that was actually observed, assuming that the null hypothesis is true. One often "rejects the null hypothesis" when the p-value is less than the significance level α ,...
) from that of distilled water, leading the authors to categorise N. eymae as a viscoelastic
Viscoelasticity
Viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Viscous materials, like honey, resist shear flow and strain linearly with time when a stress is applied. Elastic materials strain instantaneously when stretched and just...
species.
Similarly viscous pitcher fluid is found in the group of 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 that includes 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:...
, N. talangensis
Nepenthes talangensis
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....
, 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...
. These species all share infundibular pitchers.
Related species
Nepenthes eymae is closely allied to the extremely polymorphic N. maximaNepenthes maxima
Nepenthes maxima , the Great Pitcher-Plant, is a carnivorous pitcher plant species of the genus Nepenthes. It has a relatively wide distribution covering Sulawesi, New Guinea, and the Maluku Islands. It is closely related to N. eymae....
, which is widespread across Sulawesi
Sulawesi
Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands. In Indonesia, only Sumatra, Borneo, and Papua are larger in territory, and only Java and Sumatra have larger Indonesian populations.- Etymology :The Portuguese were the first to...
, New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
, and the Maluku Islands
Maluku Islands
The Maluku Islands are an archipelago that is part of Indonesia, and part of the larger Maritime Southeast Asia region. Tectonically they are located on the Halmahera Plate within the Molucca Sea Collision Zone...
. It differs from this species in its wingless, infundibular and relatively small upper pitchers, ovate lower pitchers, and hastate lid. While some forms of N. maxima also produce entirely infundibular aerial traps, these are not usually as abruptly contracted (and therefore wine glass
Wine glass
A wine glass is a type of glass stemware that is used to drink and taste wine. It is generally composed of three parts: the bowl, stem, and foot...
-shaped) as in N. eymae, and may or may not have fringed wings. Where the two species grow side-by-side, introgression
Introgression
Introgression, also known as introgressive hybridization, in genetics is the movement of a gene from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species...
may blur these morphological boundaries and make circumscription difficult. Like N. eymae, N. maxima and N. klossii
Nepenthes klossii
Nepenthes klossii is a tropical pitcher plant endemic to New Guinea.-Botanical history:Nepenthes klossii was discovered in southwestern New Guinea during the Wollaston Expedition of 1912 to 1913...
(another closely related species) also commonly have two lid appendages.
Nepenthes fusca
Nepenthes fusca
Nepenthes fusca , or the Dusky Pitcher-Plant, is a tropical pitcher plant endemic to Borneo. It is found throughout a wide altitudinal range and is almost always epiphytic in nature, primarily growing in mossy forest....
of Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
may produce aerial pitchers resembling those of N. eymae, although its lower pitchers are considerably narrower and cylindrical in shape. The lower pitchers of N. eymae could potentially be confused with those of another Bornean endemic, N. veitchii
Nepenthes veitchii
Nepenthes veitchii |James Veitch]], nurseryman of the Veitch Nurseries), or Veitch's Pitcher-Plant, is a Nepenthes species from the island of Borneo. The plant is widespread in north-western Borneo and can also be found in parts of Kalimantan. N...
, although otherwise these species have little in common, particularly with respect to the upper pitchers.
External links
- Photographs of N. eymae at the Carnivorous Plant Photofinder