{{short description|Species of pitcher plant from Sumatra}} {{Speciesbox |image = Nepentheslongifolia.jpg |image_caption = An intermediate pitcher of ''N. longifolia'' |status = LC |status_system = IUCN3.1 |status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Clarke, C.M. |date=2018 |title=''Nepenthes longifolia'' |volume=2018 |article-number=e.T48993569A143971039 |doi=10.2305/IUCN.UK.2018-1.RLTS.T48993569A143971039.en |access-date=19 November 2021}}</ref> |genus = Nepenthes |species = longifolia |authority = Nerz & Wistuba (1994)<ref name=N&W>Nerz, J. & A. Wistuba 1994. [http://www.carnivorousplants.org/cpn/Species/v23n4p101_114.html Five new taxa of ''Nepenthes'' (Nepenthaceae) from North and West Sumatra] {{Webarchive|url=https://web.archive.org/web/20110805161400/http://www.carnivorousplants.org/cpn/Species/v23n4p101_114.html |date=2011-08-05 }}. ''Carnivorous Plant Newsletter'' '''23'''(4): 101–114.</ref> |synonyms = {{collapsible list|bullets = true |title=<small>Synonyms</small> |''Nepenthes rafflesiana'' var. ''longicirrhosa'' <small>''nom.nud.''<br />Tamin & M.Hotta ''in'' M.Hotta (1986)<ref name=T&H>{{in lang|id}} Tamin, R. & M. Hotta 1986. ''Nepenthes'' di Sumatera: The genus ''Nepenthes'' of the Sumatra Island. In: M. Hotta (ed.) ''Diversity and Dynamics of Plant Life in Sumatra: Forest Ecosystem and Speciation in Wet Tropical Environments. Part 1: Reports and Collection of Papers.'' Kyoto University, Kyoto. pp. 75–109.</ref></small> |''Nepenthes sumatrana''<br /><small>''auct. non'' (Miq.) Beck: Jebb & Cheek (1997);<ref name=J&C>Jebb, M.H.P. & M.R. Cheek 1997. A skeletal revision of ''Nepenthes'' (Nepenthaceae). ''Blumea'' '''42'''(1): 1–106.</ref> Cheek & Jebb (2001)<ref name=C&J>Cheek, M.R. & M.H.P. Jebb 2001. Nepenthaceae. ''Flora Malesiana'' '''15''': 1–157.</ref><br />[<nowiki>=</nowiki>''N. longifolia/N. sumatrana'']</small> }} |}}
'''''Nepenthes longifolia''''' ({{IPAc-en|n|ᵻ|ˈ|p|ɛ|n|θ|iː|z|_|ˌ|l|ɒ|ŋ|ɡ|ɪ|ˈ|f|oʊ|l|i|ə}}) is a tropical pitcher plant endemic to Sumatra, where it grows at elevations of between 300 and 1,100 m above sea level. The specific epithet ''longifolia'', formed from the Latin words ''longus'' (long) and ''folius'' (leaf), refers to the exceptionally large leaves of this species.<ref name=Clarke>Clarke, C.M. 2001. ''Nepenthes of Sumatra and Peninsular Malaysia''. Natural History Publications (Borneo), Kota Kinabalu.</ref>{{Clarify|Folius is not leaf as folium is. Could someone check whether this mistake was made in the original publication.|date=July 2019}}
==Botanical history==
The first known collection of ''N. longifolia'' was made by Willem Meijer in 1957. The specimen ''Meijer 6913'' was collected on August 24, 1957,{{Ref_label|A|note a|none}} in a sandstone region of the river Tjampo near Taram in West Sumatra, at an altitude of 500–1,000 m. The plant was growing in forest on the slope of a river valley. The specimen is sheet H.L.B. 958.85111 at the National Herbarium of the Netherlands in Leiden.<ref name=N&W />
In 1986, Rusjdi Tamin and Mitsuru Hotta invalidly described ''Nepenthes rafflesiana'' var. ''longicirrhosa''.<ref name=T&H /> Charles Clarke observed this taxon at the type locality in 1995 and concluded that it is conspecific with ''N. longifolia''.<ref name=Clarke1997>Clarke, C.[M.] 1997. [http://carnivorousplants.org/cpn/samples/v26n1p4_10.html Another Nice Trip to Sumatra]. ''Carnivorous Plant Newsletter'' '''26'''(1): 4–10.</ref> Subsequent revisions of the genus have formally synonymised these taxa.<ref name=Clarke />
''Nepenthes longifolia'' was formally described{{Ref_label|B|note b|none}} by Joachim Nerz and Andreas Wistuba in a 1994 issue of the ''Carnivorous Plant Newsletter''.<ref name=N&W /> The holotype of ''N. longifolia'', ''Nerz 2801'', was collected by Joachim Nerz on September 25, 1992, in the Tjampo Mountains near Taram, West Sumatra, at an altitude of 1,000 m. It is deposited at the National Herbarium of the Netherlands in Leiden.<ref name=N&W /> Seven other specimens of ''N. longifolia'' were collected on the same day and at the same location; ''Nerz 2802'', ''2803'', ''2804'', and ''2805'' are deposited at the National Herbarium of the Netherlands (L) together with the holotype, while ''Nerz 2806'', ''2807'', and ''2808'' are held at the Institut für Biologie I at the University of Tübingen (TUB) in Germany.<ref name=N&W />
Matthew Jebb and Martin Cheek treated ''N. longifolia'' in synonymy with ''N. sumatrana'' in their 1997 monograph, "A skeletal revision of ''Nepenthes'' (Nepenthaceae)".<ref name=J&C /> The authors tentatively upheld this synonymy in their 2001 revision, "Nepenthaceae", writing:<ref name=C&J />
<blockquote>Although we treat ''N. longifolia'' as a synonym [of ''N. sumatrana''], it is representative of other specimens from inland Sumatra, at higher altitudes (c. 1,000 m) that show differences from the plants at sea level on the coast. The inland plants have more slender pitchers which are ellipsoid in the lower half and cylindrical in the upper (not infundibuliform), with an elliptic (not a suborbicular) lid. However, intermediates are reported. More specimens are needed before ''N. longifolia'' can be fully resolved.</blockquote>
The most recent taxonomic revision by Charles Clarke, ''Nepenthes of Sumatra and Peninsular Malaysia'' (2001), elevated ''N. longifolia'' to species status once again.<ref name=Clarke />
==Description==
''Nepenthes longifolia'' is a strong climber; the stem often grows to 10 m and can attain a length of up to 12 m. It is up to 9 mm in diameter. Internodes are sub-cylindrical in cross section and up to 12 cm long.<ref name=Clarke />
thumb|left|A lower pitcher
Leaves are coriaceous in texture. The lamina is lanceolate to lanceolate-spathulate<ref name=N&W /> or lanceolate-obovate<ref name=Clarke /> in shape and up to 55 cm long and 9 cm wide. It has an emarginate apex. The lamina is gradually attenuate into a short petiole (≤7 cm). The petiole is decurrent into a pair of wings (≤2 mm wide) that extend over almost the whole length of the internode. Three<ref name=N&W /> to eight<ref name=Clarke /> longitudinal veins are present on either side of the midrib. Pinnate veins are numerous but indistinct. Tendrils are usually shorter or as long as the lamina,<ref name=N&W /> although they may be as long as 110 cm.<ref name=Clarke />
Rosette and lower pitchers are infrequently produced and are borne on very long tendrils. They are ventricose<ref name=N&W /> or narrowly ovoid<ref name=Clarke /> in the lower part and cylindrical above. They grow up to 20 cm high and 5 cm wide. A pair of fringed wings (≤5 mm wide) runs down the front of the pitcher. The fringe elements are up 6 mm long and are spaced 1 to 3 mm apart. The pitcher mouth has an oblique insertion and is acuminate towards the lid. The peristome is flattened, up to 6 mm wide, and has a distinct raised section at the front, often with one or two notches. It is broadly cylindrical in cross section and bears a series of ribs spaced 0.2 mm apart. The glandular region covers the ventricose portion of the inner surface. Overarched glands are present at a concentration of around 500 per square centimetre. The pitcher lid or operculum is orbicular<ref name=N&W /> or ovate,<ref name=Clarke /> up to 3 cm in diameter, and lacks appendages. A number of large round to ovate glands are concentrated near the midrib on the lower surface of the lid. An unbranched spur (≤15 mm long) is inserted near the base of the lid.<ref name=N&W /><ref name=Clarke />
thumb|A light green upper pitcher
Upper pitchers arise gradually from the end of the tendril, forming a curve up to 4 cm wide. They are narrowly infundibular in the lowermost parts, slightly ovoid up to the hip, and cylindrical or tubulose above. Upper pitchers are produced on shorter tendrils, but are larger than their lower counterparts, growing to 25 cm in height and 4 cm in width. They have a pair of prominent ribs in place of wings, sometimes bearing fringe elements near the peristome. As in lower pitchers, the mouth is oblique, elevated, and acuminate towards the lid. The flattened peristome is up to 6 mm wide. It has a raised section at the front and is characteristically crumpled into 3 prominent folds. The glandular region covers the infundibulate part of the inner surface, with around 500 glands per square centimetre. The lid and spur are similar to those of lower pitchers.<ref name=N&W /><ref name=Clarke />
''Nepenthes longifolia'' has a racemose inflorescence. Male and female inflorescences have the same structure. The peduncle is up to 25 cm long and 3 mm wide.<ref name=N&W /> The rachis is also up to 25 cm long. Partial peduncles are one- or two-flowered, up to 15 mm long, and may or may not be bracteolate. Sepals are ovate and up to 5 mm long. Stamens are approximately 5 mm long including the anthers.<ref name=N&W /> Seed capsules are up to 3 cm long.<ref name=Clarke />
Most parts of the plant bear a short, sparse indumentum of simple and stellate hairs. However, many of these hairs are caducous and so mature plants appear mostly glabrous. The margins of the lamina are densely lined with short reddish-brown hairs.<ref name=N&W /><ref name=Clarke />
The stem and leaves are green, the latter sometimes having a reddish lower surface. Leaves of rosette plants often have a red midrib. Lower pitchers are generally brownish-red with a green to reddish-green peristome. The inner surface of the pitcher is usually pale green and the lid is red. Upper pitchers are characteristically light green throughout.<ref name=N&W />
==Ecology==
''Nepenthes longifolia'' occurs in the Indonesian province of West Sumatra and may also be present in North Sumatra. It grows terrestrially in dense, shady lowland or submontane forest on steep sandstone slopes and ridges. As a result of developing against such inclined surfaces, the leaves of rosette plants often assume an almost vertical orientation. The species has an altitudinal distribution of 300 to 1,100 m above sea level.<ref name=N&W /><ref name=Clarke />{{Ref_label|C|note c|none}}
Around the river Tjampo in West Sumatra, ''N. longifolia'' is sympatric with ''N. adnata'', ''N. albomarginata'', ''N. ampullaria'', ''N. eustachya'', ''N. gracilis'', and ''N. reinwardtiana''. However, the species is only known to hybridise with ''N. eustachya''.<ref name=Clarke /> On Mount Tjampo itself, ''N. longifolia'' grows in a number of isolated patches and is sympatric with ''N. albomarginata'', ''N. eustachya'', and ''N. reinwardtiana''.<ref name=N&W />
Plants resembling the type of ''N. longifolia'' are abundant along the road from Sibolga to Tarutung in North Sumatra. They differ from those of West Sumatra in a number of morphological features and may represent the poorly known ''N. beccariana''. This taxon is sympatric with ''N. ampullaria'', ''N. gracilis'', ''N. rafflesiana'', ''N. reinwardtiana'', and ''N. tobaica''.<ref name=Clarke />
''Nepenthes longifolia'' is not listed on the 2006 IUCN Red List of Threatened Species as the list follows Jebb and Cheek in treating ''N. longifolia'' in synonymy with ''N. sumatrana''. The combined conservation status for both taxa is listed as Least Concern.<ref>{{cite iucn |author=Clarke, C.M. |date=2014 |title=''Nepenthes sumatrana'' |volume=2014 |article-number=e.T39700A21845285 |doi=10.2305/IUCN.UK.2014-1.RLTS.T39700A21845285.en |access-date=19 November 2021}}</ref> However, recent studies have shown that these two taxa are distinct species.<ref name=Clarke /> In 2001, Charles Clarke suggested a revised status of Vulnerable for ''N. longifolia'' based on the IUCN criteria.<ref name=Clarke /> The habitat of this species may be threatened in the near future by fires deliberately started to clear forest for agricultural purposes.<ref name=Clarke />
==Related species== {{multiple image | align = right | image1 = Neplongifolia.jpg | width1 = 170 | alt1 = | caption1 = | image2 = Nsumatrana11.jpg | width2 = 170 | alt2 = | caption2 = | footer = An upper pitcher of ''N. longifolia'' (left) and an upper pitcher of ''N. sumatrana'' (right) }} ''Nepenthes longifolia'' is thought to be most closely related to ''N. sumatrana''; the stem and lamina of these species are virtually identical in appearance. Nevertheless, ''N. longifolia'' can be distinguished from ''N. sumatrana'' on the basis of a number of significant and stable morphological differences. The tendrils on rosette leaves of ''N. longifolia'' are exceptionally long, reaching 110 cm, while those of ''N. sumatrana'' are not known to exceed 60 cm. As a result, the lower pitchers of ''N. longifolia'' are usually around 1/10 the length of the tendril, compared to 1/5 in the case of ''N. sumatrana''. Although the lower pitchers on immature rosettes are similar in general morphology, the species differ in the shape of lower pitchers on rosettes sprouting from mature plants. Those of ''N. sumatrana'' are ovoid throughout, with an orbicular lid and the hip immediately beneath the peristome, and are contracted at an angle of 45° to the mouth. Those of ''N. longifolia'' are ovoid in the lower parts, having the hip around the middle and an ovate lid. In addition, the upper pitchers of ''N. longifolia'' do not give off a noticeable smell, whereas those of ''N. sumatrana'' have a sweet, fruity fragrance. In addition, the upper pitchers of ''N. longifolia'' are only infundibular in the lower parts, compared to the wholly infundibular aerial pitchers of ''N. sumatrana''. Furthermore, the peristome of ''N. longifolia'', although distinctly notched, is never raised at the front like in ''N. rafflesisna'', unlike that of ''N. sumatrana'', which has a very pronounced raised section.<ref name=Clarke /> In their description of ''N. longifolia'', Nerz and Wistuba also used the structure of the inflorescence to distinguish these taxa,<ref name=N&W /> but subsequent observations have shown that both species produce one- and two-flowered partial peduncles.<ref name=Clarke />
''Nepenthes longifolia'' is also closely related to ''N. rafflesiana''. It can be distinguished from that species on the basis of its fringed leaf margins, very long tendrils of rosettes, upper pitchers that are cylindrical above the hip, and the notched peristome which is not greatly expanded near the lid as in ''N. rafflesiana''.<ref name=Clarke />
{{multiple image | align = right | image1 = Nepenthes beccariana Macfarlane illustration.jpg | width1 = 170 | alt1 = | caption1 = | image2 = Nepenthes beccariana1.jpg | width2 = 196 | alt2 = | caption2 = | footer = The illustration of ''N. beccariana'' from Macfarlane's monograph (left) and an upper pitcher of a plant from Sibolga that resembles ''N. beccariana'' (right) }}
Plants that resemble the type of ''N. longifolia'' grow along the road from Sibolga to Tarutung in North Sumatra. They are atypical of the species in that the leaf bases are not decurrent along the internode, some of the hairs lining the leaf margins are caducous, and the plants grow in both exposed sites and amongst dense vegetation. This taxon is also similar to, and may be conspecific with, the obscure ''N. beccariana''.<ref name=Clarke />
''Nepenthes beccariana'' was described by John Muirhead Macfarlane in 1908 based on a specimen collected on Nias, an island located approximately 120 km from the port town of Sibolga. Twenty years later, B. H. Danser synonymised the taxon with ''N. mirabilis'' in his seminal monograph "The Nepenthaceae of the Netherlands Indies", although he did not see the type specimen of ''N. beccariana''.<ref name=Danser>Danser, B.H. 1928. The Nepenthaceae of the Netherlands Indies. ''Bulletin du Jardin Botanique de Buitenzorg'', Série III, '''9'''(3–4): 249–438.</ref> In 2000, Jan Schlauer and C. Nepi examined the type specimen of ''N. beccariana'' and noted significant differences between it and ''N. mirabilis'', suggesting that it should be restored as a distinct species.<ref name=S&N>Schlauer, J. & C. Nepi 2000. Notes on ''Nepenthes'' (Nepenthaceae). II. Lectotypification of names based on material represented in the Herbarium Beccarianum. ''Webbia'' '''55''': 1–5.</ref> Charles Clarke agrees that ''N. beccariana'' appears to be distinct from both ''N. mirabilis'' and ''N. sumatrana'' but notes that if ''N. beccariana'' is found to be conspecific with ''N. longifolia'', the latter taxon would become a junior synonym of the former. However, observations of ''N. beccariana'' at the type locality would need to be carried out to resolve this taxonomic confusion, since the type specimen of ''N. beccariana'' only consists of fragments of three leaves and three pitchers (two rosette pitchers and one upper pitcher) and is in a damaged state; the leaves are separated from the stem such that their attachment is unknown.<ref name=Clarke />
In 2001, Clarke published a cladistic analysis of the ''Nepenthes'' species of Sumatra and Peninsular Malaysia based on 70 morphological characteristics of each taxon. The following is a portion of the resultant cladogram, showing part of "Clade 5", which has 69% bootstrap support. The sister pair of ''N. rafflesiana'' and ''N. sumatrana'' has 58% support.<ref name=Clarke /> ''N. beccariana'' was not included in this study.
{{clade| style=font-size:100%;line-height:80% |label1= |1={{clade |label1=69% |1={{clade |label1=<span style="color:white;">unnamed</span> |1={{clade |1=''N. longifolia'' }} |label2=<span style="color:white;">unnamed</span> |2={{clade |label1=58% |1={{clade |1=''N. rafflesiana'' |2=''N. sumatrana'' }} }} }} }} }} thumb|A rosette plant of ''N. adnata'' growing on a cliff face Seedlings of ''N. adnata'' and ''N. longifolia'' are virtually indistinguishable, although mature plants have few morphological features in common. Clarke writes that ''N. longifolia'' is likely to be one of the closest relatives of ''N. adnata''.<ref name=Clarke />
==Natural hybrids== Despite occurring sympatrically with a number of other ''Nepenthes'' species, ''N. longifolia'' appears to hybridise very rarely; only one natural cross with ''N. eustachya'' is known with confidence,<ref name=Clarke /> although it may also hybridise with ''N. sumatrana''.<ref name=McPherson>McPherson, S.R. 2009. ''Pitcher Plants of the Old World''. 2 volumes. Redfern Natural History Productions, Poole.</ref>
''Nepenthes eustachya'' × ''N. longifolia'' has been recorded from a number of locations near Payakumbuh and Sibolga, where its parent species are sympatric. It is relatively rare because ''N. eustachya'' and ''N. longifolia'' occur in markedly different habitats; the former usually grows in exposed, sunny sites, while the latter is more common in dense, shady forest. This hybrid differs from ''N. eustachya'' in having fringed lamina margins bearing short reddish-brown hairs. The peristome often has a distinctive raised section at the front, a characteristic inherited from ''N. longifolia''. It can be distinguished from ''N. longifolia'' on the basis of its shorter tendrils and the presence of longitudinal furrows on the surface of the lamina, similar to those of ''N. eustachya''.<ref name=Clarke />
==Notes== {{refbegin}} :a.{{Note_label|A|a|none}}Meijer explored the forest of the Tjampo region between August 20 and August 28.<ref>van Steenis-Kruseman, M.J., ''et al.'' 2006. [http://www.nationaalherbarium.nl/FMCollectors/M/MeijerW.htm Cyclopaedia of Malesian Collectors: Prof.dr. Willem ('Wim') Meijer]. Nationaal Herbarium Nederland.</ref> He collected ''N. longifolia'' on August 24 together with the type material of ''N. adnata'' and ''N. tenuis''.<ref name=Clarke />
:b.{{Note_label|B|b|none}}The original Latin description of ''N. longifolia'' reads:<ref name=N&W />
<blockquote>Folia mediocria, lamina oblongavel lanceolata, nervis longitudionalibus utrinque 3-4, basi in alas 2 decurrente; Ascidia rosularum mediocria, parte inferiore ventricosa os versus cylindrica, ails 2 fimbriatis; ascidia facie ventrali sub peristomio elevata quomodo peristomio inter alis distinctissime undulato, operculum versus acuminato et elevato, ad 6 mm lato, costis 0,2 mm distantibus, dentibus 0. Operculo orbiculari, facie inferiore plano. Ascidia superioria magna, e parte inferiore anguste infundibuliformi tubulosa, costis 2 prominentibus, ascidia facie ventrali sub peristomio elevata quomodo peristomio inter alis distinctissime undulato, operculum versus acuminato et elevato, ad 6 mm lato, costis 0,2 mm distantibus, dentibus 0. Operculo orbiculari, facie inferiore piano. Inflorescentia racemus, pedicellis 1-1,2 cm longis, omnibus 2-floris. Indumentum parcum breve patens.</blockquote>
:c.{{Note_label|C|c|none}}The upper altitudinal limit of ''N. longifolia'' is given as 1200 m in a comparison table on page 158 of ''Nepenthes of Sumatra and Peninsular Malaysia'', but appears as 1100 m elsewhere in the book,<ref name=Clarke /> and this latter value is the one included in subsequent works on the genus.<ref name=McPherson /><ref name=NewMcPherson>McPherson, S.R. 2011. ''New Nepenthes: Volume One''. Redfern Natural History Productions, Poole.</ref><ref name=JavaSumatra>McPherson, S.R. & A. Robinson 2012. ''Field Guide to the Pitcher Plants of Sumatra and Java''. Redfern Natural History Productions, Poole.</ref> {{refend}}
==References== {{Reflist}}
==Further reading== {{Refbegin|2}} * 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. {{doi|10.1111/j.1420-9101.2011.02406.x}} * 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. {{doi|10.1111/j.1469-8137.2011.03696.x}} * Hernawati & P. Akhriadi 2006. ''A Field Guide to the Nepenthes of Sumatra''. PILI-NGO Movement, Bogor. * 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. {{doi|10.1055/s-2001-12897}} * {{in lang|de}} Meimberg, H. 2002. {{cite web |url=http://edoc.ub.uni-muenchen.de/1078/1/Meimberg_Harald.pdf |title=Molekular-systematische Untersuchungen an den Familien Nepenthaceae und Ancistrocladaceae sowie verwandter Taxa aus der Unterklasse Caryophyllidae s. l..}} Ph.D. thesis, Ludwig-Maximilians-Universität München, Munich. * Meimberg, H. & G. Heubl 2006. Introduction of a nuclear marker for phylogenetic analysis of Nepenthaceae. ''Plant Biology'' '''8'''(6): 831–840. {{doi|10.1055/s-2006-924676}} * 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. {{doi|10.1016/j.ympev.2005.11.023}} {{Refend}}
==External links== {{Commons}} * [http://www.joachim-nerz.de/longi.htm ''Nepenthes longifolia'' in its natural habitat]
{{Nepenthes}} {{Taxonbar|from=Q13652516}}
longifolia Category:Endemic flora of Sumatra Category:Carnivorous plants of Asia Category:Plants described in 1994