''Nepenthes mikei'' 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 ...

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 ...

. It is characterised by its black mottled lower and upper pitchers. The species is closely related to '' N. angasanensis'' and '' N. tobaica''.Clarke, C.M. 2001. ''

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 (Borneo ...

''. Natural History Publications (Borneo), Kota Kinabalu. 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 ...

''mikei'' honours Mike Hopkins, who co-discovered the species with the describing authors.

Botanical history

''Nepenthes mikei'' was discovered on

Mount Pangulubao Mount Pangulubao or Pangulubau ( id, Gunung Pangulubao) is a mountain near Lake Toba in Sumatra. Mount Pangulubao is notable for its large number of native tropical pitcher plant species. These include ''Nepenthes ampullaria'', '' Nepenthes gym ...

in September 1989 by Bruce Salmon, Mike Hopkins, and Ricky Maulder, during a ''Nepenthes'' expedition to

. On this trip, the team also found two other undescribed ''Nepenthes''

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

on the mountain: '' N. ovata'' and a plant they named '' N. xiphioides''. The latter is now 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 ...

of '' N. gymnamphora''.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. An early colour photograph of ''N. mikei'' was published by Mike Hopkins, Ricky Maulder, and Bruce Salmon, in a 1990 issue of the ''

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 ...

'', where the plant was identified simply as ''Nepenthes'' sp. 'New Species'. The authors described it as follows:

We saw another ''Nepenthes'' that is different than the others we saw in the higher highland areas. It has small pitchers slightly similar to '' N. tentaculata'', '' N. tobaica'' and '' N. gracilis'' but tougher and thicker. The pitchers are always nicely colored with blackish lines and markings similar to '' N. fusca''. There was very little variation with this species as all mature plants had ample rosettes on the ground and also at intervals up the stem. The stems were slimbing up to about 7 meters and had upper pitchers similar in color and shape to the lower pitchers but with the usual differences. The male inflorescences were about 20 centimeters, peduncle inclusive.

Prior to its description, ''N. mikei'' was known as ''N. minutissima'' among pitcher plant growers. This name is a ''

nomen nudum In taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published with an adequate descr ...

'' (naked name), as it was never formally published. ''Nepenthes mikei'' was formally described by Bruce Salmon and Ricky Maulder in a 1995 issue of the ''Carnivorous Plant Newsletter''. 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 ''B.Salmon & R.Maulder 221719'' is the designated

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 ...

, and is deposited at the

Auckland Institute and Museum Auckland Institute and Museum, known as Auckland Museum Institute since 1996 and the Royal Society of New Zealand Auckland Branch, is a learned society in New Zealand. History Formed as the Auckland Philosophical Society on 6 November 1867, for ...

(AK) in

Auckland Auckland (pronounced ) ( mi, Tāmaki Makaurau) is a large metropolitan city in the North Island of New Zealand. The List of New Zealand urban areas by population, most populous urban area in the country and the List of cities in Oceania by po ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

.Schlauer, J. N.d
''Nepenthes mikei''
Carnivorous Plant Database. It was prepared on February 17, 1995, from a plant cultivated in

, and consists of a vine bearing a

female Female (Venus symbol, symbol: ♀) is the sex of an organism that produces the large non-motile ovum, ova (egg cells), the type of gamete (sex cell) that fuses with the Sperm, male gamete during sexual reproduction. A female has larger gamet ...

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 ...

, a lower pitcher, and a rosette. The specimen was originally collected in 1989 from a "very steep ridge in wet mossy forest" near the summit of

, at an altitude of 2000 m. The authors described the plant as growing "in

peat Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...

humus In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Lati ...

or moss at the base of 5–6 m tall trees". Salmon and Maulder also pressed a second specimen of ''N. mikei'' from material collected at the same elevation on Pangulubao. Additional herbarium specimens of ''N. mikei'' are known and these show slight morphological variability. In 1997,

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.A skeletal revision of ''Nepenthes'' (Nepenthaceae)", in which they provided an emended description of ''N. mikei'' that encompassed specimens of the closely related, and at the time undescribed, '' N. angasanensis'' from

Mount Leuser The Leuser Range or Leuser Massif, known as Mount Leuser is a group of three peaks, is the highest mountain in the Indonesian province of Aceh. The range lies to the south and west of the Alas River that flows east from the highlands of centra ...

, Goh Lembuh, and the Kappi region. Salmon and Maulder did not support this interpretation and reinstated their original description of ''N. mikei'' when they described ''N. angasanensis'' in 1999. Jebb and Cheek retained ''N. angasanensis'' as a synonym of ''N. mikei'' in their 2001 monograph, " Nepenthaceae", writing: "We suspect that it 'N. angasanensis''may prove not distinct from ''N. mikei'' and here treat it as a synonym."

Description

''Nepenthes mikei'' is a climbing plant growing to a height of 7 m. The

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

, which may be branched, is up to 0.4 cm in diameter and has cylindrical to angular

internodes A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, stores nutrien ...

measuring up to 9 cm in length. Plants from

Mount Bandahara 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 ...

are known to produce offshoots from short underground

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

s. ''Nepenthes mikei'' is noted for rapidly transitioning from a rosette to a climbing stage; sequential internodal lengths of 2–3 mm and 10 cm have been recorded. Leaves are

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

and

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 ...

in texture. 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 linear and measures up to 10 cm in length by 2 cm in width. Its apex may be acute or obtuse and it is abruptly contracted at the base, clasping the stem for around half of its circumference. One to two longitudinal veins are present on either side of the

midrib 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 ...

, while

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 irregularly

reticulate Reticulation is a net-like pattern, arrangement, or structure. Reticulation or Reticulated may refer to: * Reticulation (single-access key), a structure of an identification tree, where there are several possible routes to a correct identificatio ...

. The upper surface of the lamina is typically green, but may be red if exposed to direct sunlight.

Tendril In botany, a tendril is a specialized stem, leaf or petiole with a threadlike shape used by climbing plants for support and attachment, as well as cellular invasion by parasitic plants such as ''Cuscuta''. There are many plants that have tendr ...

s are up to 15 cm long. Rosette and lower pitchers are

ovate Ovate may refer to: *Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe *Ovates, one of three ranks of membership in the Welsh Gorsedd *Vates In modern English, the nouns vates () and ovat ...

in the basal third to quarter of the pitcher cup, becoming approximately cylindrical above and

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 ...

towards the pitcher mouth. They are relatively small, growing to only 12 cm in height by 3 cm in width. A pair of wings (≤4 mm wide) typically runs down 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, with fringe elements measuring up to 8 mm in length. These wings may be reduced to ribs in some plants. The

gland In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure De ...

ular region on the inner surface is restricted to the ovate portion of the pitcher cup. The glands are small (0.2–0.3 mm in diameter) and occur at a density of around 150–180 per square centimetre. The waxy zone is well developed and eye spots may occasionally be present on the rear inner surface, visible through the opening. 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 sub-cylindrical to cylindrical and up to 4 mm wide. It bears ribs up to 0.1 mm high and spaced 0.2 mm apart, which terminate in teeth up to 0.4 mm long. The inner portion of the peristome accounts for around 51% 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 pitcher lid or operculum is ovate and has a

cordate Cordate is an adjective meaning 'heart-shaped' and is most typically used for: * Cordate (leaf shape), in plants * Cordate axe, a prehistoric stone tool See also * Chordate A chordate () is an animal of the phylum Chordata (). All chordat ...

base. It measures up to 3 cm in length by 2.5 cm in width and does not bear any appendages. The underside of the lid has an even distribution of small (0.1–0.2 mm in diameter) convex glands, occurring at a density of about 40/cm². The

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 ...

, which is inserted near the base of the lid, is up to 7 mm long and may be simple, forked, or fasciculate with up to 12 branches.

Upper pitchers are ovate in their basal third to fifth, becoming cylindrical above and infundibular towards the peristome. They are smaller than their lower counterparts, reaching only 8 cm in height by 2 cm in width. Wings are always reduced to ribs. In other respects, upper pitchers are similar to the lower traps. ''Nepenthes mikei'' 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 ...

measuring up to 18 cm in length by 1.8 cm in diameter. The peduncle itself may be up to 8 cm long by 1 mm wide in female plants, and up to 3 cm long in males. 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 ...

is up to 8 cm long. The inflorescence bears one-flowered

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 ...

(≤6 mm long), which may be

bracteole 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 ...

ate. The oblong-

lanceolate 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 ...

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 measure up to 4 mm in length.

Fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

s are up to 22 mm long. Most parts of the plant are

glabrous Glabrousness (from the Latin ''glaber'' meaning "bald", "hairless", "shaved", "smooth") is the technical term for a lack of hair, down, setae, trichomes or other such covering. A glabrous surface may be a natural characteristic of all or part of ...

. 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 short, white or yellowish hairs is usually present on the tendrils and some parts of the inflorescence. This indumentum is a mixture of simple and stellate hairs.

Caducous Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits, anthers and sporangia. Sometimes this involves the complete detachment of a part; structures that op ...

hairs cover developing pitchers and other parts.

Ecology

''Nepenthes mikei'' is

to the

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

n island of

, where it has been recorded from only two mountains:

North Sumatra North Sumatra ( id, Sumatra Utara) is a province of Indonesia located on the northern part of the island of Sumatra. Its capital and largest city is Medan. North Sumatra is Indonesia's fourth most populous province after West Java, East Java and ...

and

Aceh Aceh ( ), officially the Aceh Province ( ace, Nanggroë Acèh; id, Provinsi Aceh) is the westernmost province of Indonesia. It is located on the northernmost of Sumatra island, with Banda Aceh being its capital and largest city. Granted a s ...

. Its altitudinal distribution extends from 1100 to 2800 m

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 ...

.McPherson, S.R. & A. Robinson 2012. ''

Field Guide to the Pitcher Plants of Sumatra and Java This list of ''Nepenthes'' literature is a listing of major published works dealing with the tropical pitcher plants of the genus ''Nepenthes''. It includes specialised standalone publications and taxonomic monographs released as part of larger ...

''. Redfern Natural History Productions, Poole.

The typical habitat of this species is summit scrub vegetation as well as lower and upper montane

mossy forest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud c ...

. It always grows terrestrially, often in open sites such as ridge tops and cliff sides, where it is exposed to direct sunlight. The species is rare in blangs, where the lack of surrounding vegetation means the stems scramble along the ground. ''Nepenthes mikei'' may be difficult to find on Mount Pangulubao, where it is

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...

with '' N. gymnamphora'' ('' N. xiphioides''), '' N. ovata'', and '' N. spectabilis''. On Mount Bandahara, where it is common above 2400 m, it grows alongside '' N. diatas''.Harwood, P., H. Rischer & A. Wistuba 1998
The carnivorous flora of Gunung Bandahara
''

'' 27(2): 59–61.

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 with all of these species have been recorded. At another location, which is undisclosed for conservation purposes, ''N. mikei'' grows alongside '' N. flava''.Wistuba, A., J. Nerz & A. Fleischmann 2007
flava'', a new species of Nepenthaceae from the northern part of Sumatra
''Blumea'' 52(1): 159–163. 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. mikei'' is listed as Vulnerable 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 2000. This agrees with an informal assessment made by

Charles Clarke Charles Rodway Clarke (born 21 September 1950) is a British Labour Party politician, who was the Member of Parliament (MP) for Norwich South from 1997 until 2010, and served as Home Secretary from December 2004 until May 2006. Early life Th ...

in 2001, who also classified the species as Vulnerable based on the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

criteria. However, Clarke noted that since substantial populations of ''N. mikei'' lie within protected areas, they "are unlikely to become threatened in the foreseeable future". Taking this into account, he suggested a revised assessment of

Conservation Dependent A conservation-dependent species is a species which has been categorised as "Conservation Dependent" ("LR/cd") by the International Union for Conservation of Nature (IUCN), i.e. as dependent on conservation efforts to prevent it from becoming e ...

. The species is threatened by habitat loss and disturbance, as well as over-collection by

plant collector Plant collecting is the acquisition of plant specimens for the purposes of research, cultivation, or as a hobby. Plant specimens may be kept alive, but are more commonly dried and pressed to preserve the quality of the specimen. Plant collecting i ...

Related species

''Nepenthes mikei'' is most closely allied to the

n endemics '' N. angasanensis'' and '' N. tobaica'', and may be conspecific with the former. In their description of ''N. mikei'', Salmon and Maulder noted many differences between it and ''N. angasanensis'' which are now known to be unreliable. For example, the authors wrote that ''N. angasanensis'' produces offshoots from underground

s, while ''N. mikei'' does not; populations of ''N. mikei'' from

are now known to produce such offshoots. Similarly, ''N. angasanensis'' was said to lack a fasciculate

, but this has since been recorded in lower pitchers of this species. Disregarding these supposed differences leaves only a few stable distinguishing features between the species. Firstly, the teeth lining the inner margin of the

are shorter in ''N. mikei'', although both have minute teeth and this difference is minor. Secondly, the

of ''N. mikei'' bear simple

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

eoles, while those of ''N. angasanensis'' do not. Finally, ''N. angasanensis'' exhibits a greater density of digestive glands on the inner pitcher surface.

''Nepenthes angasanensis'' and ''N. mikei'' are more easily distinguished by their differing ecology. While ''N. angasanensis'' is generally found growing terrestrially or

epiphytically 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 ...

in shady

, ''N. mikei'' is always terrestrial and favours more exposed sites where it receives strong sunlight. ''Nepenthes angasanensis'' also typically produces longer stems, with regular offshoots from the leaf axils, although these have been observed in ''N. mikei'' as well. ''Nepenthes tobaica'' differs from ''N. mikei'' in a number of floral and vegetative features. Whereas the latter has a shorter

with flowers borne singly on

, ''N. tobaica'' has two-flowered partial peduncles. In addition, ''N. tobaica'' lacks the fasciculate spur of ''N. mikei'' and generally has wider laminae. Salmon and Maulder also compared ''N. mikei'' to '' N. adnata'' and '' N. tentaculata''. Stewart McPherson noted that the species may also superficially resemble '' N. eustachya'' in the shape of its pitchers. In 2001,

performed a

cladistic analysis Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived chara ...

of the ''Nepenthes'' species of Sumatra and

Peninsular Malaysia Peninsular Malaysia ( ms, Semenanjung Malaysia; Jawi: سمننجڠ مليسيا), or the States of Malaya ( ms, Negeri-negeri Tanah Melayu; Jawi: نڬري-نڬري تانه ملايو), also known as West Malaysia or the Malaysian Peninsula, ...

using 70 morphological characteristics of each taxon. The following is a portion of the resultant

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

, showing part of "Clade 6". The sister pair of ''N. angasanensis'' and ''N. mikei'' has 79% support. Clarke concluded that the "relationships between hese speciesare very complex and are somewhat difficult to interpret at present".

Natural hybrids

Four

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 involving ''N. mikei'' have been recorded.

''N. diatas'' × ''N. mikei''

Nepenthes diatas ''Nepenthes diatas'' (; from Indonesian ''diatas'' "above, on top") is a tropical pitcher plant endemic to Sumatra, where it grows at an altitude of above sea level. ''Nepenthes diatas'' was formally described in 1997 by Matthew Jebb and Ma ...

'' is restricted to

and thus this hybrid only occurs on that mountain. This cross is common between 2300 and 2700 m, where the altitudinal ranges of the two species overlap. It was first reported in 1998. This hybrid is similar to ''N. mikei'' and also produces mostly black lower pitchers. It differs in that the terrestrial traps have a wider basal portion. The plant is also larger in stature, having broader stems and leaves, and bears a wider peristome than ''N. mikei''. ''Nepenthes diatas'' × ''N. mikei'' has only been found at the forest margins in the summit area of Mount Bandahara. It has not been recorded from the mountain's open blangs.

Other hybrids

Three other natural hybrids — with '' N. gymnamphora'', '' N. ovata'', and '' N. spectabilis'' — have been observed. All three were first reported in 1995 by Salmon and Maulder from

. ''Nepenthes gymnamphora'' × ''N. mikei'' was given the informal name '' N. × pangulubauensis'' in 1996.Schlauer, J. N.d
''Nepenthes × pangulubauensis''
Carnivorous Plant Database.

Notes

:a.The second specimen of ''N. mikei'', ''B.Salmon & R.Maulder 221718'', was collected at the same elevation as the holotype and pressed on the same day. It consists of two lower pitchers, two upper pitchers, and a short shoot with pitchers. This specimen is also deposited at the Auckland Institute and Museum (AK). :b.The herbarium specimen ''de Wilde & de Wilde-Duyfjes 13190'' exhibits pitchers with forked spurs, unlike the fasciculate spurs of the holotype. It is 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 ...

Bogor Bogor ( su, , nl, Buitenzorg) is a city in the West Java province, Indonesia. Located around south of the national capital of Jakarta, Bogor is the 6th largest city in the Jakarta metropolitan area and the 14th overall nationwide.Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...

References

* Meimberg, H., A. Wistuba, P. Dittrich & G. Heubl 2001. Molecular phylogeny of Nepenthaceae based on cladistic analysis of plastid trnK intron sequence data. ''Plant Biology'' 3(2): 164–175. * Meimberg, H. 2002. Ph.D. thesis, Ludwig Maximilian University of Munich, Munich. * Meimberg, H. & G. Heubl 2006. Introduction of a nuclear marker for phylogenetic analysis of Nepenthaceae. ''Plant Biology'' 8(6): 831–840. * Meimberg, H., S. Thalhammer, A. Brachmann & G. Heubl 2006. Comparative analysis of a translocated copy of the ''trnK'' intron in carnivorous family Nepenthaceae. ''Molecular Phylogenetics and Evolution'' 39(2): 478–490.

External links

Photographs of ''N. mikei''
at the Carnivorous Plant Photofinder {{Taxonbar, from=Q5460405 Carnivorous plants of Asia mikei Endemic flora of Sumatra Plants described in 1995 Vulnerable plants