Thespecific epithetalbomarginata, formed from theLatin wordsalbus (white) andmarginatus (margin), refers to the white band oftrichomes that is characteristic of this species.[4]
Nepenthes albomarginata is a climbing plant. The stem may reach lengths of up to 4 metres (13 ft) and is up to 5 millimetres (0.20 in) in diameter.Internodes are cylindrical in cross section and up to 15 centimetres (5.9 in) long.[8]
Leaves arecoriaceous in texture. Thelamina or leaf blade islanceolate in shape and up to 25 centimetres (9.8 in) long by 2 centimetres (0.79 in) wide. It has an acute apex and its base is graduallyattenuate andamplexicaul. The leaves of this species are characteristic in that they completely lack apetiole. Longitudinal veins are indistinct.Tendrils are up to 20 centimetres (7.9 in) long.[8]
Rosette and lower pitchers are bulbous in the basal third and cylindrical above. They are relatively small, reaching only 15 centimetres (5.9 in) in height by 4 centimetres (1.6 in) in width. A pair of fringed wings up to 5 millimetres (0.20 in) wide runs down the front of each pitcher. The pitcher mouth is round and rises to form a short neck at the rear. Theperistome is cylindrical in cross section, up to 2 millimetres (0.079 in) wide, and bears indistinct teeth.[8] The inner portion of the peristome accounts for around 34% of its total cross-sectional surface length.[9] A dense band of short whitetrichomes is present directly below the peristome, although these may be missing from pitchers that have caughttermites. Theglandular region covers the bulbous portion of the pitcher's inner surface. The lid oroperculum issuborbicular and lacks appendages. An unbranchedspur (≤3 millimetres (0.12 in) long) is inserted near the base of the lid.[8]
Upper pitchers are similar to their lower counterparts in most respects. They are cylindrical-infundibular throughout and have a pair of ribs in place of wings.[8]
Nepenthes albomarginata has aracemoseinflorescence that is usually longer in male plants. Thepeduncle is up to 25 centimetres (9.8 in) long, while therachis reaches lengths of up to 40 centimetres (16 in). Partial peduncles are one- or two-flowered, up to 30 millimetres (1.2 in) long, and lack abract.Sepals areobovate to oblong in shape and up to 4 millimetres (0.16 in) long.[8] A study of 120pollen samples taken from a herbarium specimen (J.H.Adam 2417, collected in Borneo at an altitude of 0–30 metres (0–98 ft)) found the mean pollen diameter to be 31.8 μm (0.00125 in) (SE = 0.4;CV = 6.2%).[10]
Most parts of the plant are covered in a denseindumentum of very short,stellate white hairs. However, the underside of the lamina bears a dense covering of long hairs.[8]
Nepenthes albomarginata is a widespread species, occurring inBorneo,Peninsular Malaysia, andSumatra. It is also found on smaller islands such asNias andPenang.[11][12] It has an altitudinal distribution of 0–1200 m above sea level.[13]
A lower pitcher with an intact band of trichomes (left) and one lacking them (right)
Nepenthes albomarginata is notable for specializing intermites; most of the species in the genusNepenthes are unselective about their prey. According tobotanistMarlis A. Merbach and coworkers, this specialization to a single prey taxon is unique amongstcarnivorous plants.[15][16][17][18][19]
Nepenthes albomarginata has a uniquemorphological feature: a rim of living whitetrichomes directly below theperistome. The rim's hairs tend to be missing from pitchers that have caught termites. Merbach said "For several days, nothing would happen, then — after a single night — pitchers would fill with termites and their rim hairs would disappear."
Merbach investigated this phenomenon by placing fresh intact pitchers, together with pitchers with their white rims removed, near to the head offoraging columns of the termiteHospitalitermes bicolor.[15] When the column found the pitcher, termites grazed on the rim.
While grazing, many termites (both workers and soldiers) fell into the pitchers. Once in the pitcher, they were unable to climb out. Merbach counted up to 22 individuals per minute falling into the pitchers and noted that the capture rate could easily exceed this for denser columns. After about an hour, the hairs were all gone and the pitcher was evidently no longer attractive to termites (and was filled with termites trying to escape).
It is not known how the trichomes lure termites to the plant. Merbach detected no long-rangeolfactory attraction during his experiments and noted that "all contacts seemed to happen by chance, with termites often missing pitchers less than 1 cm away from them."
Merbach also points out thatN. albomarginata is the onlyplant species to offer its tissue as a bait.
In 2001, Clarke performed acladistic analysis of theNepenthes species of Sumatra andPeninsular Malaysia using 70 morphological characteristics of each taxon. The following is a portion of the resultantcladogram, showing "Clade 6", which is only weakly supported at 50%. The sister pair ofN. angasanensis andN. mikei has 79% support.[4]
Lower pitchers ofN. adnata (left) and a purple form ofN. albomarginata (right)
Nepenthes × cincta is a rare plant and, due to the localised distribution ofN. northiana, only grows at a few sites inBau,Sarawak, usually on asubstrate oflimestone.
The traits ofN. albomarginata are very dominant in this hybrid; the wide flared peristome of its larger parent species (N. northiana) is almost completely lost. Pitchers are narrowlyinfundibulate (funnel-shaped) throughout and range in colour from cream to dusky purple with red or black spots.[27]
^Bauer, U., C.J. Clemente, T. Renner & W. Federle 2012. Form follows function: morphological diversification and alternative trapping strategies in carnivorousNepenthes pitcher plants.Journal of Evolutionary Biology25(1): 90–102.doi:10.1111/j.1420-9101.2011.02406.x
^Anderson, J.A.R. 1965. Limestone habitat in Sarawak.Proceedings of the Symposium on Ecological Research in Humid Tropics Vegetation, July 1963, Kuching, Sarawak. pp. 49–57.
^Merbach, M.A., D.J. Merbach, W.E. Booth, U. Maschwitz, G. Zizka & B. Fiala 2000. A unique niche in plant carnivory:Nepenthes albomarginata feeds on epigaeically mass foraging termites. Tagungsband gtö 2000 13. Jahrestagung der Deutschen Gesellschaft für Tropenökologie 1–3. March 2000 in Würzburg Lehrstuhl für Tierökologie und Tropenbiologie Universität Würzburg. p. 105.
Beveridge, N.G.P., C. Rauch, P.J.A. Keßler, R.R. van Vugt & P.C. van Welzen 2013. A new way to identify living species ofNepenthes (Nepenthaceae): more data needed!Carnivorous Plant Newsletter42(4): 122–128.
(in French) Blondeau, G. 2001.Nepenthes albomarginata. In:Les Plantes Carnivores. De Vecchi, Paris. p. 69.
Bonhomme, V., H. Pelloux-Prayer, E. Jousselin, Y. Forterre, J.-J. Labat & L. Gaume 2011. Slippery or sticky? Functional diversity in the trapping strategy ofNepenthes carnivorous plants.New Phytologist191(2): 545–554.doi:10.1111/j.1469-8137.2011.03696.x
Kato, M., M. Hotta, R. Tamin & T. Itino 1993. Inter- and intra-specific variation in prey assemblages and inhabitant communities inNepenthes pitchers in Sumatra.Tropical Zoology6(1): 11–25.Abstract
(in Indonesian) Mansur, M. 2007. Keanekaragaman jenisNepenthes (kantong semar) dataran rendah di Kalimantan Tengah. [Diversity of lowlandNepenthes (kantong semar) in Central Kalimantan.]Berita Biologi8(5): 335–341.Abstract
Meimberg, H., A. Wistuba, P. Dittrich & G. Heubl 2001. Molecular phylogeny of Nepenthaceae based on cladistic analysis of plastid trnK intron sequence data.Plant Biology3(2): 164–175.doi:10.1055/s-2001-12897
Meimberg, H. & G. Heubl 2006. Introduction of a nuclear marker for phylogenetic analysis of Nepenthaceae.Plant Biology8(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 thetrnK intron in carnivorous family Nepenthaceae.Molecular Phylogenetics and Evolution39(2): 478–490.doi:10.1016/j.ympev.2005.11.023
Osunkoya, O.O., S.D. Daud & F.L. Wimmer 2008. Longevity, lignin content and construction cost of the assimilatory organs ofNepenthes species.Annals of Botany102(5): 845–853.doi:10.1093/aob/mcn162
Renner, T. & C.D. Specht 2011. A sticky situation: assessing adaptations for plant carnivory in the Caryophyllales by means of stochastic character mapping.International Journal of Plant Sciences172(7): 889–901.doi:10.1086/660882
Riedel, M., A. Eichner, H. Meimberg & R. Jetter 2007. Chemical composition of epicuticular wax crystals on the slippery zone in pitchers of fiveNepenthes species and hybrids.Planta225(6): 1517–1534.doi:10.1007/s00425-006-0437-3
Smythies, B.E. 1965. The distribution and ecology of pitcher-plants (Nepenthes) in Sarawak. UNESCO Humid Tropics Symposium, June–July 1963, Kuching, Sarawak.
Takeuchi, Y., M.M. Salcher, M. Ushio, R. Shimizu-Inatsugi, M.J. Kobayashi, B. Diway, C. von Mering, J. Pernthaler & K.K. Shimizu 2011.In situ enzyme activity in the dissolved and particulate fraction of the fluid from four pitcher plant species of the genusNepenthes.PLoS ONE6(9): e25144.doi:10.1371/journal.pone.0025144
Wan, A.S., R.T. Aexel, R.B. Ramsey & H.J. Nicholas 1972. Nepenthaceae: sterols and triterpenes of the pitcher plant.Phytochemistry11(1): 456–461.doi:10.1016/S0031-9422(00)90055-4
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