''Nepenthes eymae'' is a tropical

pitcher plant Pitcher plants are several different carnivorous plants which have modified leaves known as pitfall traps—a prey-trapping mechanism featuring a deep cavity filled with digestive liquid. The traps of what are considered to be "true" pitcher p ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Sulawesi Sulawesi (), also known as Celebes (), is an island in Indonesia. One of the four Greater Sunda Islands, and the world's eleventh-largest island, it is situated east of Borneo, west of the Maluku Islands, and south of Mindanao and the Sulu Ar ...

in Indonesia, where it grows at elevations of

above sea level Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The comb ...

. It is very closely related to '' N. maxima'', from which it differs in its

wine glass A wine glass is a type of glass that is used to drink and taste wine. Most wine glasses are stemware (goblets), i.e., they are composed of three parts: the bowl, stem, and foot. Shapes The effect of glass shape on the taste of wine has not been ...

-shaped upper pitchers.McPherson, S.R. 2009. ''

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 and covers all species kno ...

''. 2 volumes. Redfern Natural History Productions, Poole. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''eymae'' honours

Pierre Joseph Eyma Pierre Joseph Eyma (25 July 1903 – 1945) was a Dutch botanist.van Steenis-Kruseman, M.J., ''et al.'' 2006Cyclopaedia of Malesian Collectors: Pierre Joseph Eyma Nationaal Herbarium Nederland. Eyma was born in Maarssen, Netherlands, in 1903. He st ...

, a Dutch botanist who worked extensively in the

Dutch East Indies The Dutch East Indies, also known as the Netherlands East Indies ( nl, Nederlands(ch)-Indië; ), was a Dutch colony consisting of what is now Indonesia. It was formed from the nationalised trading posts of the Dutch East India Company, which ...

and who originally discovered the species.

Botanical history

''Nepenthes eymae'' was discovered in central Sulawesi by Dutch botanist Pierre Joseph Eyma in 1938.D'Amato, P. 1993
''Nepenthes eymai''.
''

Carnivorous Plant Newsletter The ''Carnivorous Plant Newsletter'' is the official publication of the International Carnivorous Plant Society (ICPS), the largest such organization in the world. It is headquartered in Walnut Creek, California. History and editorship The newsle ...

'' 22(1–2): 21. Eyma's original material of this species includes the

herbarium A herbarium (plural: herbaria) is a collection of preserved plant specimens and associated data used for scientific study. The specimens may be whole plants or plant parts; these will usually be in dried form mounted on a sheet of paper (called ...

specimen ''Eyma 3968'', which bears a male

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. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

. ''Nepenthes eymae'' was formally described by

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.Clarke, C.M. & C.C. Lee 2004. ''Pitcher Plants of Sarawak''. Natural History Publications (Borneo), ...

in a 1984 issue of ''

The Journal of Insectivorous Plant Society is a quarterly Japanese-language periodical and the official publication of the Insectivorous Plant Society of Japan.Rice, B. 2010Carnivorous Plant Society Archives The Carnivorous Plant FAQ. rchived page from October 10, 2010/ref> The journal ...

''.''Nepenthes eymae'' Shigeo Kurata

International Plant Names Index The International Plant Names Index (IPNI) describes itself as "a database of the names and associated basic bibliographical details of seed plants, ferns and lycophytes." Coverage of plant names is best at the rank of species and genus. It inclu ...

(IPNI). The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, designated as ''Kurata, Atsumi & Komatsu 102a'', was collected on the northern spur of Mount Lumut in

Central Sulawesi Central Sulawesi (Indonesian: ''Sulawesi Tengah'') is a province of Indonesia located at the centre of the island of Sulawesi. The administrative capital and largest city is located in Palu. The 2010 census recorded a population of 2,635,009 for ...

,Schlauer, J.
''Nepenthes eymae''
Carnivorous Plant Database. at an altitude of 1850 m, on November 5, 1983. A series of isotypes (''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 Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

(NDC).Cheek, M.R. & M.H.P. Jebb 2001.

Nepenthaceae ''Nepenthes'' () is a genus of carnivorous plants, also known as tropical pitcher plants, or monkey cups, in the monotypic family Nepenthaceae. The genus includes about 170 species, and numerous natural and many cultivated hybrids. They are mos ...

. ''Flora Malesiana'' 15: 1–157. Despite this, the species name is valid per Article 37 of the ''

International Code of Botanical Nomenclature The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "trad ...

'', and Kurata's description includes an illustration of the holotype on page 44. Kurata published the species with the

''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 ''Reinwardtia indica'', yellow flax or pyoli, is a species of Linaceae found in the Himalayas. It is the only species in the monotypic genus ''Reinwardtia''. Distribution This flower comes from Himalayas in both China and northern India. Uses ...

''. 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 The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnae ...

. 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 Mount is often used as part of the name of specific mountains, e.g. Mount Everest. Mount or Mounts may also refer to: Places * Mount, Cornwall, a village in Warleggan parish, England * Mount, Perranzabuloe, a hamlet in Perranzabuloe parish, C ...

in Sulawesi at the coordinates , 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 The Bogor Botanical Gardens ( id, Kebun Raya Bogor) is a botanical garden located in Bogor, Indonesia, 60 km south of central Jakarta. It is currently operated by Indonesian Institute of Sciences (Indonesian: ''Lembaga Ilmu Pengetahuan Indo ...

, but

Matthew Jebb Matthew Hilary Peter Jebb (born 1958) is an Irish botanist and taxonomist specialising in the ant plant genera ''Squamellaria'', ''Myrmecodia'', ''Hydnophytum'', ''Myrmephytum'' and ''Anthorrhiza'', as well as the carnivorous plant genus ''Nepe ...

and

Martin Cheek Martin Roy Cheek (born 1960) is a botanist and taxonomist at the Royal Botanic Gardens, Kew.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)Jebb, M.H.P. & M.R. Cheek 1997. A skeletal revision of ''Nepenthes'' (Nepenthaceae). ''Blumea'' 42(1): 1–106. and "

" (2001), as well as Stewart McPherson's ''

'' (2009). Nonetheless, some authors have expressed doubt that it merits distinction from '' N. maxima'' at the species level.D'Amato, P. 1998. '' The Savage Garden: Cultivating Carnivorous Plants''. Ten Speed Press, Berkeley.Evans, D.P. 2009
New cultivars: ''Nepenthes maxima'' ‘Lake Poso’
''

'' 38(1): 18–22. 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". Whatever the status of this taxon, the vast majority of plants cultivated under the name ''N. eymae'' do not exhibit the abruptly contracted upper pitchers commonly associated with it.

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 bud The axillary bud (or lateral bud) is an embryonic or organogenic shoot located in the axil of a leaf. Each bud has the potential to form shoots, and may be specialized in producing either vegetative shoots (stems and branches) or reproductive sh ...

s, which are found 3–10 mm above the

leaf axil A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...

s in climbing stems, are spike-like and measure up to 10 mm (rarely 20 mm) in length by 1.5 mm in width. Nepenthes eymae2

Leaves are

coriaceous This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...

and

petiolate Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, a ...

. The

lamina Lamina may refer to: Science and technology * Planar lamina, a two-dimensional planar closed surface with mass and density, in mathematics * Laminar flow, (or streamline flow) occurs when a fluid flows in parallel layers, with no disruption betwee ...

(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 following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

. The base is obtuse and

attenuate In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable a ...

, 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 ''Decurrent'' (sometimes decurring) is a term used in botany and mycology to describe plant or fungal parts that extend downward. In botany, the term is most often applied to leaf blades that partly wrap or have wings around the stem or petio ...

, sending off a pair of low ridges to the node below. Longitudinal and

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

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 Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

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 waxy zone of the inner surface is reduced. The pitcher mouth is ovate and concave, and has an oblique insertion. The

peristome Peristome (from the Greek ''peri'', meaning 'around' or 'about', and ''stoma'', 'mouth') is an anatomical feature that surrounds an opening to an organ or structure. Some plants, fungi, and shelled gastropods have peristomes. In mosses In mosses, ...

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 A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...

, whereas the inner margin is deeply incurved, especially towards the back of the pitcher. The inner portion of the peristome accounts for around 34% of its total cross-sectional surface length.Bauer, U., C.J. Clemente, T. Renner & W. Federle 2012. Form follows function: morphological diversification and alternative trapping strategies in carnivorous ''Nepenthes'' pitcher plants. ''Journal of Evolutionary Biology'' 25(1): 90–102. 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 The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

apex and a

truncate In mathematics and computer science, truncation is limiting the number of digits right of the decimal point. Truncation and floor function Truncation of positive real numbers can be done using the floor function. Given a number x \in \mathbb ...

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 Filiform, thread or filament like, can refer to: *Filiform, a common term used in botany to describe a thread-like shape *Filiform, or filiform catheter, a medical device whose component parts or segments are all cylindrical and more or less uni ...

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 A spur is a metal tool designed to be worn in pairs on the heels of riding boots for the purpose of directing a horse or other animal to move forward or laterally while riding. It is usually used to refine the riding aids (commands) and to back ...

up to 10 mm long is inserted near the base of the lid. Upper pitchers are narrowly

infundibular An infundibulum (Latin for ''funnel''; plural, ''infundibula'') is a funnel-shaped cavity or organ. Anatomy * Brain: the pituitary stalk, also known as the ''infundibulum'' and ''infundibular stalk'', is the connection between the hypothalamus and ...

in the basal half to three-quarters, rapidly expanding to become broadly infundibular in the upper portion.Wistuba, A. 2001
''Nepenthes'' photographs.
''

'' 30(2): 63. 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

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

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 Bifid refers to something that is split or cleft into two parts. It may refer to: * Bifid, a variation in the P wave, R wave, or T wave in an echocardiogram in which a wave which usually has a single peak instead has two separate peaks * Bifid ci ...

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 A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the s ...

. 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 In biology, a rachis (from the grc, ῥάχις [], "backbone, spine") is a main axis or "shaft". In zoology and microbiology In vertebrates, ''rachis'' can refer to the series of articulated vertebrae, which encase the spinal cord. In this c ...

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 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 usually different from foliage leaves. They may be smaller, larger, or of ...

and number 30–40. They are approximately 4 mm long, being formed from a pair of basally-united

pedicels In botany, a pedicel is a stem that attaches a single flower to the inflorescence. Such inflorescences are described as ''pedicellate''. Description Pedicel refers to a structure connecting a single flower to its inflorescence. In the absenc ...

around 10 mm long.

Tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s are elliptic and around 4 mm long by 2 mm wide. The androphore is around 4 mm long and bears an

anther The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

head measuring 1 mm by 1.5 mm. An

indumentum In biology, an indumentum (Latin, literally: "garment") is a covering of trichomes (fine "hairs") on a plant Davis, Peter Hadland and Heywood, Vernon Hilton (1963) ''Principles of angiosperm taxonomy'' Van Nostrandpage, Princeton, New Jersey, pa ...

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.

s are red. No

infraspecific taxa In botany, an infraspecific name is the scientific name for any taxon below the rank of species, i.e. an infraspecific taxon or infraspecies. (A "taxon", plural "taxa", is a group of organisms to be given a particular name.) The scientific names ...

of ''N. eymae'' have been described. Nepenthes eymae9

Ecology

''Nepenthes eymae'' is

to the Indonesian island of Sulawesi. It has been recorded from the

provinces A province is almost always an administrative division within a country or state. The term derives from the ancient Roman ''provincia'', which was the major territorial and administrative unit of the Roman Empire's territorial possessions outsi ...

(including the East Peninsula) and

West Sulawesi West Sulawesi ( id, Sulawesi Barat) is a province of Indonesia. It is located on the western side of Sulawesi island. It covers an area of 16,787.18 km2, and its capital is Mamuju. The 2010 Census recorded a population of 1,158,651, while t ...

. 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

, typically being found above 1400 m. The species generally grows terrestrially, but may also be

epiphytic An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...

at higher elevations. It has been recorded from a wide variety of habitats, including

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 (also kn ...

, river banks, exposed sites such as cliff faces and landslides, and disturbed or recovering

secondary vegetation A secondary forest (or second-growth forest) is a forest or woodland area which has re-grown after a timber harvest or clearing for agriculture, until a long enough period has passed so that the effects of the disturbance are no longer evident. I ...

(such as previously logged

dipterocarp Dipterocarpaceae is a family of 16 genera and about 695 known species of mainly tropical lowland rainforest trees. The family name, from the type genus ''Dipterocarpus'', is derived from Greek (''di'' = two, ''pteron'' = wing and ''karpos'' = fru ...

forest). Towards the upper end of its altitudinal range, ''N. eymae'' is found among the ridge and summit vegetation of upper

montane forest Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

. The species occurs in both shaded and exposed sites, but grows best in the latter. ''Nepenthes eymae'' has no confirmed

natural hybrid In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in ...

s, although

introgression Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Intr ...

may take place where this species is sympatric with '' N. maxima''. The

conservation status The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation ...

of ''N. eymae'' is listed as

Least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

, based on an assessment carried out in 2018. 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 Protected areas or conservation areas are locations which receive protection because of their recognized natural, ecological or cultural values. There are several kinds of protected areas, which vary by level of protection depending on the ena ...

( Morowali Nature Reserve), although the full extent of its range is unknown.

Carnivory

''Nepenthes eymae'' produces an extremely thick,

mucilaginous Mucilage is a thick, gluey substance produced by nearly all plants and some microorganisms. These microorganisms include protists which use it for their locomotion. The direction of their movement is always opposite to that of the secretion of m ...

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 is an American author, businessman, and carnivorous plant authority. He is the owner of California Carnivores, located in Sebastopol, possibly the largest nursery of carnivorous plants in the world, and the author of '' The Savage ...

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 In the physical sciences, relaxation usually means the return of a perturbed system into equilibrium. Each relaxation process can be categorized by a relaxation time τ. The simplest theoretical description of relaxation as function of time ' ...

of 0.096 seconds (± 0.000) for this species.Bonhomme, V., H. Pelloux-Prayer, E. Jousselin, Y. Forterre, J.-J. Labat & L. Gaume 2011. Slippery or sticky? Functional diversity in the trapping strategy of ''Nepenthes'' carnivorous plants. ''New Phytologist'' 191(2): 545–554. 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 In materials science and continuum mechanics, viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Viscous materials, like water, resist shear flow and strain linearly wi ...

species. Similarly viscous pitcher fluid is found in the group of closely allied

Sumatra Sumatra is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the sixth-largest island in the world at 473,481 km2 (182,812 mi.2), not including adjacent i ...

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

pitchers.

Related species

''Nepenthes eymae'' belongs to the loosely defined "''N. maxima'' complex", which also includes, among other species, '' N. boschiana'', '' N. chaniana'', '' N. epiphytica'', '' N. faizaliana'', '' N. fusca'', '' N. klossii'', '' N. maxima'', '' N. platychila'', '' N. stenophylla'', and '' N. vogelii''.Robinson, A.S., J. Nerz & A. Wistuba 2011. ''Nepenthes epiphytica'', a new pitcher plant from East Kalimantan. In: McPherson, S.R. '' New Nepenthes: Volume One''. Redfern Natural History Productions, Poole. pp. 36–51. ''Nepenthes eymae'' is very closely allied to the extremely polymorphic '' N. maxima'', which is widespread across Sulawesi,

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

, and the

Maluku Islands The Maluku Islands (; Indonesian: ''Kepulauan Maluku'') or the Moluccas () are an archipelago in the east of Indonesia. Tectonically they are located on the Halmahera Plate within the Molucca Sea Collision Zone. Geographically they are located eas ...

. It differs from this species in its wingless,

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

-shaped) as in ''N. eymae'', and may or may not have fringed wings. Where the two species grow side-by-side,

may blur these morphological boundaries and make

circumscription Circumscription may refer to: *Circumscribed circle *Circumscription (logic) *Circumscription (taxonomy) * Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthrop ...

difficult. Like ''N. eymae'', ''N. maxima'' and '' N. klossii'' (another closely related species) also commonly have two lid appendages. ''

Nepenthes fusca ''Nepenthes fusca'' , or the dusky pitcher-plant,Phillipps, A. & A. Lamb 1996. ''Pitcher-Plants of Borneo''. Natural History Publications (Borneo), Kota Kinabalu. is a tropical pitcher plant endemic to Borneo. It is found throughout a wide alti ...

'' of

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and eas ...

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.

Notes

:a.Jan Schlauer's Carnivorous Plant Database lists the specimen number as ''83140a'' and the collection date as September 29, 1983. :b.Other published specimens of ''N. eymae'' include ''Lack & Grimes 1786'' (includes a climbing stem with an upper pitcher) and ''Cheek s.n.'' (includes a lower pitcher). Both of these specimens, along with ''Eyma 3968'', are illustrated in a line drawing by Camilla Speight in

Martin Cheek Martin Roy Cheek (born 1960) is a botanist and taxonomist at the Royal Botanic Gardens, Kew.Matthew Jebb Matthew Hilary Peter Jebb (born 1958) is an Irish botanist and taxonomist specialising in the ant plant genera ''Squamellaria'', ''Myrmecodia'', ''Hydnophytum'', ''Myrmephytum'' and ''Anthorrhiza'', as well as the carnivorous plant genus ''Nepe ...

's 2001 monograph, "

References

External links

Photographs of ''N. eymae''
at the Carnivorous Plant Photofinder {{Taxonbar, from=Q4911481 Carnivorous plants of Asia eymae Endemic flora of Sulawesi Plants described in 1984