Species
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Nepenthes rajah Hook.fil.

Nepenthaceae

Climate known 9 photographs Carnivorous plant
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Every figure on this page is derived from public data by a stated rule and says its source; nothing here is written by a person or a model, except the Wikipedia passage, which is quoted and marked as such. How it is made.

Summary

Nepenthes rajah is a carnivorous pitcher plant species of the family Nepenthaceae. It is endemic to Mount Kinabalu and neighbouring Mount Tambuyukon in Sabah, Malaysian Borneo. Nepenthes rajah grows exclusively on serpentine substrates, particularly in areas of seeping ground water where the soil is loose and permanently moist. The species has an altitudinal range of 1,500–2,650 m (4,920–8,690 ft) above sea level and is thus considered a highland or sub-alpine plant. More on Wikipedia ›

The opening of Wikipedia, “Nepenthes rajah”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.

About the genus · Nepenthes

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 mostly liana-forming plants of the Old World tropics, ranging from South China, Indonesia, Malaysia, and the Philippines; westward to Madagascar and the Seychelles (one); southward to Australia (four) and New Caledonia (one); and northward to India (one) and Sri Lanka (one). More on Wikipedia ›

The opening of Wikipedia, “Nepenthes”, CC BY-SA 4.0, quoted as written.

Family
Nepenthaceae
Described by
Hook.fil.
Native to
Borneo
Wild records
60 in range· 7 open

At a glance

Warmest month
22°C
Apr, mean day; nights 13 °C (CHELSA)
Rain
3206mm/yr
12 wet months · peak Oct 353 mm (CHELSA)
Light
27–36DLI
mol/m²/day, winter to summer, open sky (CHELSA shortwave)
In short condensed by rule from the cultivation cards · not written by a person
Grouped as a carnivorous plant by the genus Nepenthes, which is reliably one kind of plant (archetype table). Rain rule: no season, 70% of the rain takes 8 months (September to January and May to July at the habitat (not shifted)). Habitat rain 3206 mm a year, wettest October at 353 mm, driest February at 171 mm (habitat calendar, northern hemisphere). Open sky over the habitat: 27 to 36 mol/m²/day. Cold floor 9.3 °C (1st-percentile habitat night, NASA POWER).
Each sentence is one card's own one-line form, written by the same rule as the card (Its year, Rain, Light, Temperature); the note cannot say what a card does not. Months are given for the northern hemisphere (set your site in Settings to change this), and the habitat's own alongside. The cards · the figures.

Cultivation

Grouped as a carnivorous plant by the genus Nepenthes, which is reliably one kind of plant (archetype table). The table holds no figure for this group, which spans too much for one minimum; the cold floor is the habitat's alone, and no prose comes from the table.

Its year Rain rule: no season, 70% of the rain takes 8 months (September to January and May to July at the habitat (not shifted)).

This species’ habitat figures, and what two fixed rules read from them.

The rain rule reads no season: 70% of the year's rain (2423 mm of 3206 mm) takes 8 months, September to January and May to July. Mean temperature moves 1.1 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere, within 10° of the equator; with no thermal season there there is no season to reverse, so they are not shifted for a collection elsewhere.

Read from the median year of CHELSA monthly rainfall and mean temperature across the envelope cells: the rain rule takes the smallest set of months carrying 70% of the rain and calls it winter when its mean is more than half a degree below the year's, summer when more than that above, and neither in between; the temperature rule, used only under 120 mm, names the cooler six months when they are at least a degree cooler than the other six. Months are shifted for the other hemisphere only where the temperature curve gives a season to reverse. A reading of the curves, not an observation of the plant.

Rain Habitat rain 3206 mm a year, wettest October at 353 mm, driest February at 171 mm (habitat calendar, northern hemisphere).

This species’ habitat figures, with their source.

3206 mm a year at the habitat, 2423 mm of it September to January and May to July. Wettest month October at 353 mm, driest February at 171 mm. Across the envelope cells the year's total runs 3123 mm to 3317 mm (10th to 90th percentile of each cell's own year) (median year across the envelope cells, CHELSA; habitat calendar, northern hemisphere).

CHELSA monthly precipitation, median year across the envelope cells. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light Open sky over the habitat: 27 to 36 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 27 to 36 mol/m²/day across the year (daily light integral, median year across the envelope cells, CHELSA; the lowest 10th-percentile month across the cells is 26, the highest 90th-percentile month 36).

CHELSA shortwave radiation at each envelope cell, a daily-mean flux taken to a daily total and converted at 2.07 mol of PAR per MJ. The sky over the habitat, measured; what reaches a plant under a rock, a shrub or a shade cloth is not.

Warmth and air Cold floor 9.3 °C (1st-percentile habitat night, NASA POWER).

This species’ habitat figures, with their source.

Temperature

Coldest: the 1st-percentile night over 44 years at the typical cell is 9.3 °C, the absolute minimum 6.5 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 20.9 °C. Monthly means: coldest night 12.2 °C in July (across the envelope cells 4.1 °C to 15.9 °C), warmest day 21.9 °C in April (median year across the envelope cells, CHELSA). Cold floor: 9.3 °C, which is the 1st-percentile night over 44 years at the typical cell (NASA POWER).

NASA POWER daily minima and maxima 1981–2024 at the typical cell, lapse-corrected to its elevation; CHELSA monthly means, median year across the envelope cells, CHELSA. The cold floor is the figure named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity

Relative humidity at the habitat: 66 to 72% across the year (monthly means, median year across the envelope cells, CHELSA). A figure about the air, saying nothing about how the plant takes water.

CHELSA relative humidity, median year across the envelope cells.

The figures the cards read from are in Climate below, and where they came from in Natural habitat.

Climate across the habitat

Habitat climate through the yearMean day from 20 °C in Jan to 22 °C in Apr; mean night from 12 °C in Jul to 13 °C in May. The cold quarter, Jun to Aug, is the three months around the coldest night. 3206 mm of rain a year, most in Oct. The bands show the 10th to 90th percentile across 4 habitat cells. Over 44 years at the typical cell the absolute minimum was 6.5 °C and the 99th-percentile day 20.9 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.10°15°20°25°30°20.9° 99th-percentile day (undated)6.5° lowest night in 44 yrs (undated)°C · day and nightcold quarter0100200300400mm rainDLI 27–36RH 66–72 %JanFebMarAprMayJunJulAugSepOctNovDec
day night rain 10th–90th percentile across 4 habitat cells cold quarter: the three months around the coldest night extremes over 44 years at the typical cell, marked at the edge: undated DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C20 / 12–2320 / 13–2421 / 14–2522 / 14–2622 / 14–2621 / 13–2521 / 13–2521 / 13–2521 / 13–2520 / 13–2420 / 13–2420 / 13–23
Night °C13 / 5–1613 / 5–1613 / 5–1613 / 5–1713 / 5–1713 / 5–1612 / 4–1612 / 4–1612 / 4–1612 / 5–1613 / 5–1613 / 5–16
Rain mm293 / 274–308171 / 160–176175 / 168–185175 / 170–188292 / 284–308281 / 277–287277 / 274–281262 / 260–265294 / 289–299353 / 346–358296 / 289–307337 / 324–357
DLI29 / 28–3032 / 31–3336 / 35–3635 / 34–3629 / 28–3227 / 26–3127 / 26–3230 / 28–3430 / 28–3429 / 26–3229 / 27–3029 / 27–29
RH %70 / 60–7368 / 59–7167 / 57–6968 / 59–6970 / 63–7068 / 64–6866 / 63–6766 / 63–6667 / 64–6870 / 66–7072 / 65–7271 / 63–73

Each figure is the median across the 4 grid cells holding the 5 in-range records, with the 10th–90th percentile span across those cells after the slash where it differs. Extremes and elevation were read at the typical cell 1679:5931 (6.025, 116.575). Over 44 years there: absolute minimum 6.5 °C, 1st-percentile night 9.3 °C, 99th-percentile day 20.9 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Envelope: median and 10th–90th percentile of each month across the 4 distinct grid cells holding the 5 in-range records; extremes and elevation at the typical cell 1679:5931 (its coldest month's mean night nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 6.00_116.875, lapse-corrected +1366 m at 6.5 °C/km. Elevation: ETOPO 2022, 1842 m (cell mean).

Natural habitat

Native range as published by WCVP; the marker is where the records are densest and decides nothing: the climate was read across every in-range record's cell, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeBorneo
Kew's description“scrambling shrub or liana” · “montane tropical”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Map marker6.05, 116.6 · in the densest population, 60 records (100% of those in range)
Evidence usedThe map marker and the climate envelope rest on all 60 georeferenced records inside the native range; the map shows only the 7 openly licensed ones, which alone would put the marker 11 km away. 55 in-range records are placed to worse than 10 km and stay on the map but off the climate.
The map markerthe map marker: the openly licensed record nearest the middle of the densest 1° population of the 60 in-range records; it decides nothing.

Photographs

Nepenthes rajahNepenthes rajahNepenthes rajahNepenthes rajahNepenthes rajahNepenthes rajahNepenthes rajahNepenthes rajah

Photographs: (c) ml_ls, some rights reserved (CC BY) (4); ml_ls, CC BY, iNaturalist via GBIF (4).

Photographs: iNaturalist did not answer when this page was built; what is shown came from the sources that did.

Papers naming this species

Works whose title or abstract names Nepenthes rajah, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

Pitchers of Nepenthes rajah collect faecal droppings from both diurnal and nocturnal small mammals and emit fruity odour
Konstans Wells, Maklarin Lakim, Stefan Schulz, Manfred Ayasse (2011) · Journal of Tropical Ecology
Tuning of color contrast signals to visual sensitivity maxima of tree shrews by three Bornean highland Nepenthes species
Jonathan A. Moran, Charles Clarke, Melinda Greenwood, Lijin Chin (2012) · Plant Signaling & Behavior
On the Cultivation of the Giant Malaysian Pitcher Plant (Nepenthes rajah)
Thomas C. Gibson (1983) · Carnivorous Plant Newsletter
PLANTS IN PERIL, 15 NEPENTHES RAJAH
R. J. S. Simpson (1991) · Curtis s Botanical Magazine
A Further Note on Nepenthes rajah Cultivation
Thomas C. Gibson (1988) · Carnivorous Plant Newsletter
Nepenthes rajah Hook. fil.
Royal Botanic Garden Edinburgh (2026) · DiSSCo
Occurrence Download
GBIF.org User (2026) · Global Biodiversity Information Facility
Occurrence Download
GBIF.org User (2026) · Global Biodiversity Information Facility
Occurrence Download
GBIF.org User (2026) · Global Biodiversity Information Facility

Similar habitat climate the 6 species whose habitat climate is nearest this one's: mean day and night, month by month, and rain on a log scale, in calendar order, so a habitat with the same seasons six months out is far, not near. Nothing else counts: not range, not family.

Other Nepenthes 174 in the reference

History & registers

Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.synonyms answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.vernacular answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
wcvp.distribution answered
gbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zam
climate answered
wikidata answeredcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
wikipedia answeredcarried from build of 2026-09-19; this build: skipped
inat.taxon not asked
inat.photos.wild answeredcarried from build of 2026-09-19; this build: skipped
inat.photos.cultivated nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
commons nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
gbif.media answered
openalex answeredcarried from build of 2026-09-19; this build: skipped

Every upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 4 datasets via GBIF.org; each carries its own licence.