Nepenthes
Uses
The main value of Nepenthes in international commerce is in the horticultural trade, where it probably far exceeds 15 million dollars per annum in our estimation (see ‘Conservation’, p. 13).
In SE Asia, the use of N. mirabilis as toy phallocrypts in New Guinea is probably the most obscure. Stems of several species are used for making rope, that of N. ampullaria being considered of particularly good quality, being very durable when used in, for ex-ample, tying fences. Fluid from unopened pitchers is potable (pers. obs.) and used to treat inflammation of the eyes and both indigestion and other stomach problems. Boiled roots of N. ampullaria and N. gracilis have both been used to treat stomachache. Nepenthes reinwardtiana has been used to facilitate healing of skin and as an astringent. Opened pitchers of the larger pitchers are used to cook rice in, imparting an interesting flavour. The last use is reflected in one of the common names of many species in various languages, which translates as ‘monkeys’ rice pots’. Other common names which may reflect uses translate as ‘monkeys’ goblet’ and ‘monkeys’ water-scooper’. A detailed compilation of common names based on those recorded on herbarium specimens is given by Danser (1928) from which most of the above uses have been obtained.
A
A. Danser, B.H. 1928: The Nepenthaceae of the Netherlands Indies. – Bull. Jard. Bot. Buitenzorg, sér. 3, 9: 249-438
In SE Asia, the use of N. mirabilis as toy phallocrypts in New Guinea is probably the most obscure. Stems of several species are used for making rope, that of N. ampullaria being considered of particularly good quality, being very durable when used in, for ex-ample, tying fences. Fluid from unopened pitchers is potable (pers. obs.) and used to treat inflammation of the eyes and both indigestion and other stomach problems. Boiled roots of N. ampullaria and N. gracilis have both been used to treat stomachache. Nepenthes reinwardtiana has been used to facilitate healing of skin and as an astringent. Opened pitchers of the larger pitchers are used to cook rice in, imparting an interesting flavour. The last use is reflected in one of the common names of many species in various languages, which translates as ‘monkeys’ rice pots’. Other common names which may reflect uses translate as ‘monkeys’ goblet’ and ‘monkeys’ water-scooper’. A detailed compilation of common names based on those recorded on herbarium specimens is given by Danser (1928) from which most of the above uses have been obtained.
A
Distribution (General)
Mostly in Malesia, but with outlying species in: Madagascar, Seychelles, Sri Lanka, NE India, Indochina, Solomon Islands, New Caledonia and Australia. Most species are found in Borneo and Sumatra.B
B. Cheek, M.R. & Jebb, M.H.P. 2001: Flora Malesiana - Nepenthaceae, Series I, Volume 15
Materials Methods
The descriptions of species that follow are based on field observations by the authors in Peninsular Malaysia, Borneo, and New Guinea and on the measurements of specimens principally at K, L, and BO, and to a lesser extent those of B, BK, BM, DBN, KEP, KLU, LAE, OXF, P, SAR, SING, SINU, TCD, U, UPNG, US, and W. Some descriptions are partly taken from protologues, usually where we have not been able to consult adequate herbarium material. For example, for N. rhombicaulis and N. sibuyanensis we have only seen sterile herbarium sheets bearing fragmentary material, and so data on the inflorescence and the range of variation in vegetative parts has been taken from the protologue. Where this has occurred it is indicated in the notes following the description. Many species are inadequately collected, even though they may be well known from popular illustrated books on Nepenthes. For example, the lower pitcher of N. bur-bidgeae is represented by only a single specimen. For many species, lower pitchers and their leaves or inflorescences or infructescences are entirely unknown. Nepenthes mollis, known only from the type specimen, is unusual in that no pitchers, either upper or lower, are known!
The format of the descriptions is unusual in the botanical world, principally in that indumentum and colour are placed at the end of the description. This standard for Nepenthes descriptions was set by Danser (1928) and has been followed by Nepenthes workers since, e.g. Jebb & Cheek (1997) and Clarke (1997). In order to be consistent, we maintain this standard here.
In order to reduce the length of descriptions, we have omitted characters of the inner pitcher surface and have cut out description of female inflorescences since they are similar to those of the male and much more rarely collected. It should be noted that our descriptions and measurements of nectar glands and indumentum are based on observation made by a Leitz monocular tt10 lens fitted with a graticule measuring to 0.1 mm. No microscope or dissections were used, and so our descriptions of hair types should not be taken as definitive.
Ranges of measurements are based on those of all the specimens that we have seen at K, L, and BO. These are cited in the exsiccatae list of Jebb & Cheek (1997). Exceptional measurements, whether small or large are placed in brackets at the upper or lower end of the range, as appropriate. Such exceptional measurements represent a single specimen that falls outside the main range of measurements. Naturally, ranges are likely to change in future descriptions if more specimens become available, particularly in the case of the many poorly collected species. Of the 83 taxa (80 species) that we recognise in Flora Malesiana, 23 are known by three or fewer collections and it is to be expected that each extra specimen collected of any of these 23 species will necessitate a modification to the ranges given here.
Please note that ranges of measurements given for lower pitchers do not include those of seedlings.
C,D,E
C. Clarke, C.M. 1997: Nepenthes of Borneo, D. Danser, B.H. 1928: The Nepenthaceae of the Netherlands Indies. – Bull. Jard. Bot. Buitenzorg, sér. 3, 9: 249-438, E. Jebb, M.H.P. & Cheek, M.R. 1997: A skeletal revision of Nepenthes. – Blumea 42(1): 1-106
The format of the descriptions is unusual in the botanical world, principally in that indumentum and colour are placed at the end of the description. This standard for Nepenthes descriptions was set by Danser (1928) and has been followed by Nepenthes workers since, e.g. Jebb & Cheek (1997) and Clarke (1997). In order to be consistent, we maintain this standard here.
In order to reduce the length of descriptions, we have omitted characters of the inner pitcher surface and have cut out description of female inflorescences since they are similar to those of the male and much more rarely collected. It should be noted that our descriptions and measurements of nectar glands and indumentum are based on observation made by a Leitz monocular tt10 lens fitted with a graticule measuring to 0.1 mm. No microscope or dissections were used, and so our descriptions of hair types should not be taken as definitive.
Ranges of measurements are based on those of all the specimens that we have seen at K, L, and BO. These are cited in the exsiccatae list of Jebb & Cheek (1997). Exceptional measurements, whether small or large are placed in brackets at the upper or lower end of the range, as appropriate. Such exceptional measurements represent a single specimen that falls outside the main range of measurements. Naturally, ranges are likely to change in future descriptions if more specimens become available, particularly in the case of the many poorly collected species. Of the 83 taxa (80 species) that we recognise in Flora Malesiana, 23 are known by three or fewer collections and it is to be expected that each extra specimen collected of any of these 23 species will necessitate a modification to the ranges given here.
Please note that ranges of measurements given for lower pitchers do not include those of seedlings.
C,D,E
Habitat & Ecology
Nepenthes are most commonly encountered in disturbed secondary forest, swamp, kerangas or heath forest from sea level to c. 700 m altitude. In such habitats however, only a few species occur, although they can be locally common. Nepenthes ampullaria, N. rafflesiana, and N. gracilis can be found in these habitats in Peninsular Malaysia, Sumatra, and Borneo, while in New Guinea N. neoguineensis and N. ampullaria occupy these niches. More locally distributed in such habitats are N. bicalcarata (Borneo), N. treubiana (W New Guinea), and N. sumatrana (WC Sumatra). Nepenthes mirabilis occurs from Indochina to N Australia, sometimes in such habitats, though it also occurs in Eucalyptus savannah and open fresh-water or brackish swamps.
The shade of undisturbed high forest is anathema to most Nepenthes. The majority of Nepenthes species are confined to montane habitats between 1500-2500 m altitude, usually in open mossy, stunted, ridge-top forest as climbers or epiphytes. A few species reach montane or subalpine grassland, for example N. lamii which reaches 3520 m alti-tude in Irian Jaya — the highest altitude known for the genus.
Some species can occur in both lowland and montane habitats, for example N. alata, N. albomarginata, N. eustachya, N. maxima, N. merrilliana, N. neoguineensis, and N. reinwardtiana, although most species occur in one or the other.
Limestone and ultramafic substrates often support open scrub or woodland and are habitats for some Nepenthes.
Obligate limestone species are known only from Borneo: N. boschiana, N. campanulata, N. faizaliana, N. mapuluensis, and N. northiana.
Facultative limestone species (Borneo only) are: N. albomarginata, N. reinwardtiana.
It is strange that no Nepenthes are reported from the limestone outcrops of Philippines, Sumatra, or New Guinea. This may be due to undercollecting.
Obligate ultramafic species are known only from N Borneo, Philippines, Sulawesi, and Waigeo Island: N. argentii, N. burbidgeae, N. danseri, N. edwardsiana, N. macrovulgaris, N. philippinensis, N. rajah, N. sibuyanensis, N. tomoriana, and N. villosa.
Suspected ultramafic obligate species (all from Mindanao) are: N. bellii, N. merrilliana, N. petiolata, and N. truncata.
Facultative ultramafic species are: N. alata, N. gracilis, N. maxima, N. mirabilis, N. rafflesiana, N. stenophylla, and N. tentaculata.
According to Brookes (1987), plant species that grow on ultramafic substrates adopt one of three physiological strategies to cope with the metal-rich conditions that are toxic to many plant species. Ultramafic dwelling plants are either metal excluders, tolerators or hyperaccumulators. Metal concentrations have been examined in only three species of Nepenthes: N. maxima, N. mirabilis, and N. reinwardtiana in a study on an ultramafic site on Obi Island, Moluccas by De Vogel reported in Brookes (1987). However, the last species is not known from the Moluccas. No vouchers are recorded. The concentrations of nickel, cobalt, and manganese present in the leaf samples taken from these species in the study show them to be metal tolerators rather than excluders or hyperaccumulators (Brookes 1987).F
F. Brookes, R.R. 1987: Serpentine & its Vegetation
The shade of undisturbed high forest is anathema to most Nepenthes. The majority of Nepenthes species are confined to montane habitats between 1500-2500 m altitude, usually in open mossy, stunted, ridge-top forest as climbers or epiphytes. A few species reach montane or subalpine grassland, for example N. lamii which reaches 3520 m alti-tude in Irian Jaya — the highest altitude known for the genus.
Some species can occur in both lowland and montane habitats, for example N. alata, N. albomarginata, N. eustachya, N. maxima, N. merrilliana, N. neoguineensis, and N. reinwardtiana, although most species occur in one or the other.
Limestone and ultramafic substrates often support open scrub or woodland and are habitats for some Nepenthes.
Obligate limestone species are known only from Borneo: N. boschiana, N. campanulata, N. faizaliana, N. mapuluensis, and N. northiana.
Facultative limestone species (Borneo only) are: N. albomarginata, N. reinwardtiana.
It is strange that no Nepenthes are reported from the limestone outcrops of Philippines, Sumatra, or New Guinea. This may be due to undercollecting.
Obligate ultramafic species are known only from N Borneo, Philippines, Sulawesi, and Waigeo Island: N. argentii, N. burbidgeae, N. danseri, N. edwardsiana, N. macrovulgaris, N. philippinensis, N. rajah, N. sibuyanensis, N. tomoriana, and N. villosa.
Suspected ultramafic obligate species (all from Mindanao) are: N. bellii, N. merrilliana, N. petiolata, and N. truncata.
Facultative ultramafic species are: N. alata, N. gracilis, N. maxima, N. mirabilis, N. rafflesiana, N. stenophylla, and N. tentaculata.
According to Brookes (1987), plant species that grow on ultramafic substrates adopt one of three physiological strategies to cope with the metal-rich conditions that are toxic to many plant species. Ultramafic dwelling plants are either metal excluders, tolerators or hyperaccumulators. Metal concentrations have been examined in only three species of Nepenthes: N. maxima, N. mirabilis, and N. reinwardtiana in a study on an ultramafic site on Obi Island, Moluccas by De Vogel reported in Brookes (1987). However, the last species is not known from the Moluccas. No vouchers are recorded. The concentrations of nickel, cobalt, and manganese present in the leaf samples taken from these species in the study show them to be metal tolerators rather than excluders or hyperaccumulators (Brookes 1987).F
Notes
Genus with 176 species and 9 natural hybrid described here (about 160 species according to Clarke & al. 2018). G
G. Berendsohn, W.G. 2017+: Compilation of Nepenthes data for the Caryophyllales taxonomic backbone.
Anatomy
Metcalfe & Chalk (1950) provide a report on the vegetative anatomy based on their examination of two horticultural hybrid taxa, Nepenthes ‘Hainaniana’ and N. ‘Ratcliffeana’ as well as summarising data from previous work. Much of what follows is based on their work.
Leaf blade with distinct palisade in some taxa, indistinct in others. Stomata on lower surface only, ranunculaceous. Hypoderm usually present, especially at the upper surface, of 1-3 cell layers. Mesophyll including up to 5 layers of palisade cells and cells with spiral bands of cellulose thickening. Midrib similar to petiole.
Petiole with vascular cylinder adaxially flattened, of widely spaced collateral bundles supported by fibres and connected by a zone of sclerotic cells. Larger adaxial bundles with xylem uppermost, smaller adaxial bundles inverted. Abaxial bundles variously orientated. One medullary bundle in one taxon, two in another; xylem adaxial. Small bundles present in petiole wings. Tanniniferous deposits and occasional cluster crystals in mesophyll cells.
Tendril with vascular cylinder of collateral bundles embedded in sclerenchyma. Adaxial bundles sometimes inverted, that is, with xylem internal. Medullary bundle(s) well developed or absent.
Pitcher with epidermis of thick-walled cells. Stomata present on outer surface, and both surfaces of the lid. Spirally thickened cells embedded, walls supplied by numerous vascular bundles with very well-developed phloem. Larger bundles sheathed in fibres (Metcalfe & Chalk 1950).H
H. Cheek, M.R. & Jebb, M.H.P. 2001: Flora Malesiana - Nepenthaceae, Series I, Volume 15
Leaf blade with distinct palisade in some taxa, indistinct in others. Stomata on lower surface only, ranunculaceous. Hypoderm usually present, especially at the upper surface, of 1-3 cell layers. Mesophyll including up to 5 layers of palisade cells and cells with spiral bands of cellulose thickening. Midrib similar to petiole.
Petiole with vascular cylinder adaxially flattened, of widely spaced collateral bundles supported by fibres and connected by a zone of sclerotic cells. Larger adaxial bundles with xylem uppermost, smaller adaxial bundles inverted. Abaxial bundles variously orientated. One medullary bundle in one taxon, two in another; xylem adaxial. Small bundles present in petiole wings. Tanniniferous deposits and occasional cluster crystals in mesophyll cells.
Tendril with vascular cylinder of collateral bundles embedded in sclerenchyma. Adaxial bundles sometimes inverted, that is, with xylem internal. Medullary bundle(s) well developed or absent.
Pitcher with epidermis of thick-walled cells. Stomata present on outer surface, and both surfaces of the lid. Spirally thickened cells embedded, walls supplied by numerous vascular bundles with very well-developed phloem. Larger bundles sheathed in fibres (Metcalfe & Chalk 1950).H
Description
Carnivorous, dioecious, woody or subwoody climbers or subshrubs, terrestrial or epiphytic. Stems terete or 2-4-angled, or winged. Buds naked, lacking scales. Phyllotaxy spiral, 2/5 or 1/2. Leaves exstipulate; involute or convolute, marcescent, simple, chartaceous or coriaceous, petiolate or sessile; midrib extended into an unbranched tendril, the distal part of which expands into an elaborate, animal trapping receptacle (pitcher) containing digestive fluid. Pitchers dimorphic. Lower pitchers produced from rosettes or short stems, often resting on the ground, usually ovoid or globular, the mouth facing towards the stem, with two ventral fringed wings running from the base to the pitcher rim and with the tendril straight, not coiled. Upper pitchers (usually absent in N. argentii, N. ampullaria, and N. pectinata) usually more elongated and infundibuliform (funnel-shaped) than the lower pitchers, the mouth facing away from the stem, the wings reduced to ridges and not fimbriate, or absent, and the tendril coiled. Pitcher mouth apical or subapical, rimmed with a ribbed peristome (except N. inermis), the inner edge often toothed and bearing nectar glands, at the rear sometimes raised to form a column, supporting the lid; lid usually held over the mouth (reflexed e.g. in N. dubia), lower surface with a laterally flattened basal appendage, rarely an apical filiform appendage, or appendages absent; nectar glands usually abundant; spur inserted on dorsal surface at junction with lid, entire or variously divided, flattened or terete. Inflorescence terminal, appearing lateral by subsequent growth, a paniculoid thyrse or raceme, of 6-300 flowers, the main axis with indeterminate growth, the partial inflorescences 1-flowered (racemose) or 2-flowered, less usually 3-40-flowered, bracteate or ebracteate. Perianth imbricate, a single whorl of 4 (also interpreted as two whorls of 2) free or basally united, patent, nectariferous tepals. Female flowers with androecium lacking, ovary superior, 4-carpellate, incompletely 4-locular locules antitepalous, placentation lamellar, ovules erect, anatropous, bitegmic, crassinucellate, 200-500, stigmas sessile, as many as locules. Male inflorescence usually larger and more floriferous, perianth as in female; stamens 4-?12, filaments united into an androphore, anthers tetrasporangiate, in 1-3 dense whorls, united into a subspherical anther head, locules opening by longitudinal slits, extrorse; gynoecium lacking. Fruit sometimes stipitate, a loculicidally dehiscent capsule with 4 valves containing 50-500 seeds. Seeds filiform, 3-25 mm long, slender due to long basal and apical appendages. Testa reduced to an outer epidermis with thick outer walls to the cells and irregular thickenings on the radial and inner walls. Tegmen produced only around the embryonic cavity, crushed. Endosperm starchy or absent. Embryo minute, central, straight or U-shaped in a subellipsoid cavity, cotyledons and hypocotyl well-developed, though minute. Indumentum of simple, bifid, fasciculate, stellate, dendritic non-glandular and sunken, sessile or shortly stipitate glandular hairs. Colour of pitchers entirely green, or yellow or orange or white or purple or red, often marked with red streaks or blotches; peristome often glossy red; inflorescence with green, brown or red tepals. 2n = 80.I
I. Cheek, M.R. & Jebb, M.H.P. 2001: Flora Malesiana - Nepenthaceae, Series I, Volume 15
Synonymy
Nepenthes, Sp. Pl.: 955. 1753 sec. Jebb & Cheek 1997
- Type: Nepenthes distillatoria
- =Bandura, Fam. Pl. 2: 75. 1763
- Type: Nepenthes distillatoria
- =Phyllamphora, Fl. Cochin. 2: 606. 1790
- Type: Nepenthes mirabilis
- =Anurosperma in Beih. Bot. Centralbl., Abt. 2, 39(2): 162. 1921
- Type: Nepenthes pervillei
Images
Keys
Polytomous
- SPOT CHARACTERS
- KEY TO THE SUMATRAN AND JAVAN SPECIES
- KEY TO THE PENINSULAR MALAYSIAN SPECIESSee key to highland species under N. gracillima or here
- KEY TO THE JAVAN SPECIES
- KEY TO THE MOLUCCAN AND SULAWESI ISLAND SPECIES
- KEY TO THE BORNEAN SPECIES
- KEY TO THE PHILIPPINE SPECIES
- KEY TO THE SPECIES OF NEW GUINEA AND NEIGHBOURING ISLANDS