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Nepenthes Rajah Plant Royal Giant Carnivorous Plant Characteristics, Reproduction, Care

real huge carnivorous plant

Nepenthes rajah is a carnivorous pitcher plant species of the Nepenthaceae family. It is common in Mount Kinabalu and adjacent to Mount Tambuyukon in Sabah, Malaysian Borneo. Nepenthes rajah grows solely on bending substrates, mainly in areas of soaking ground water where the soil is loose and eternally humid. N. rajah is categorized as an endangered species by the IUCN and registered on CITES Appendix I.

Nepenthes rajah is most well-known for the giant urn-shaped traps it creates, which can grow up to 41 cm high and 20 cm wide. These are able of holding 3.5 liters of water and in surplus of 2.5 liters of digestive fluid, making them perhaps the major in the genre by volume.

The plant is recognized to trap vertebrates and even small mammals, with sunk rats having been witnessed in the pitcher-shaped traps. It is one of merely three Nepenthes species acknowledged as having trapped mammalian prey in the wild, the others being Nepenthes rafflesiana and attenboroughii. Rajah is also known to sporadically catch tiny vertebrates such as frogs, lizards and even birds, though these cases possibly include ill animals and surely do not signify the custom. Insects, and mainly ants, encompass the essential prey in both aerial and terrestrial pitchers.

Although Nepenthes rajah is most famous for entrapping and processing animals, its pitchers are also mass to a large number of other organisms, which are thought to form a mutually beneficial (symbiotic) association with the plant. Several of these animals are so specialized that they cannot survive anywhere else, and are referred to as nepenthebionts. Nepenthes rajah has two such mosquito taxa named after it: Culex rajah and Toxorhynchites rajah.



Nepenthes Rajah features
This unit can be more than 40 cm high and store up to 3.5 liters of fluid inside.

Nepenthes rajah, like almost every other species in the genre, is a climbing liana. The stem typically raises sideways the earth, but will try to climb at whatever time it comes into interaction with an object that can hold it. The stem is fairly dense (≤30 mm) and might extent up to 6 m in size, though it rarely surpasses 3 m. Nepenthes rajah does not create runners as some other species in the genre, but older plants are known to form basal sprouts.


Leaves are formed at consistent interludes along the stem. They are linked to the stem by enclosed structures known as petioles. An extended, thin vine originates from the end of each leaf. At the tip of the vine is a small blossom which, when physiologically triggered, progresses into an effective trap. Henceforth, the pitchers are adapted leaves and not specialized flowers as is frequently supposed. The green structure most alike to a normal leaf is explicitly known as the lamina or leaf blade.

The leaves of Nepenthes rajah are very distinctive and stretch a large size. They are rubbery in consistency with an undulating external border. The leaves are routinely peltate, whereby the vine joints the lamina on the base, afore the peak. This trait is more marked in Nepenthes rajah than in any other Nepenthes species, with the exception of Nepenthes clipeata. Nonetheless, it is not exclusive to these two taxa, as mature plants of numerous Nepenthes species show faintly peltate foliage. The vines are injected ≤5 cm below the leaf peak and achieve a length of around 50 cm.


Every Nepenthes pitchers share numerous simple physiognomies. Traps reside of the main pitcher cup, which is enclosed by an operculum or cover that averts rainwater from incoming the pitcher and dislocating or weakening its contents. A reflexed ring of hardboiled matter, recognized as the peristome, encircles the entry to the pitcher. A couple of fringed wings run down the border of lower traps and these seemingly aid to guide earthly bugs into the pitchers’ mouth. Thus, the wings are significantly condensed or wholly missing in aerial pitchers, for which winged bugs institute the mainstream of prey items.

Nepenthes rajah, like most species in the genre, creates two dissimilar types of traps. “Lower” or “terrestrial” pitchers are the most frequent. These are very outsized, splendidly colored, and ovoid in shape. In lower pitchers, the stem addition happens at the front of the pitcher cup comparative to the peristome and wings. Remarkable samples might be more than 40 cm in size and grasp 3.5 liters of water and in surplus of 2.5 liters of digestive fluid, although most do not surpass 200 ml.

The lower pitchers of Nepenthes rajah are perhaps the biggest in the genre by volume, equaled only by those of Nepenthes merrilliana and truncata and the colossal shape of Nepenthes rafflesiana. These traps repose on the earth and are frequently lounged, tilting against nearby objects for sustenance. They are typically red to purple on the exterior, while the inside surfaces are lime green to purple. This differences with all other parts of the plant, which are yellow-green. The lower pitchers of Nepenthes rajah are unique and for this reason it is effortless to differentiate it from all other Bornean Nepenthes species.

Developed plants might also manufacture “upper” or “aerial” pitchers, which are much reduced, funnel-shaped, and generally less colorful than the lowers. The stem supplement in upper pitchers is generally existent at the rear of the pitcher cup. True upper pitchers are rarely observed, as the stems of Nepenthes rajah hardly reach sizes larger than a little meters afore dying off and being substituted by off-shoots from the central rootstock.

Upper and lower pitchers contrast meaningfully in morphology, as they are dedicated to charm and catch dissimilar types of prey. Pitchers that do not fall right into either class are merely identified as “intermediate” pitchers.

The peristome of Nepenthes rajah has an exceedingly characteristic scalloped verge and is prominently extended, creating a striking red lip around the trap’s mouth. A sequence of elevated lumps, known as ribs, pass across the peristome, finishing in small, shrill teeth that line its inner margin. The inner ration of the peristome accounts for about 80% of its total cross-sectional surface measurement in this species. Two fringed wings run from the stem addition to the inferior verge of the peristome.

The massive, curved cover of Nepenthes rajah, the biggest in the genre, is one more unique characteristic of this species. It is egg-shaped to parallelogram in shape and has a clear keel running down the middle, with two noticeable sideways veins. The limb at the back of the cover is around 20 mm lengthy and unbranched.

Nepenthes rajah is well-known for having very outsized nectar-secreting glands masking its pitchers. These are rather unalike from those of any other Nepenthes and are easily identifiable. The inner surface of the pitcher, in specific, is absolutely glandular, with 300 to 800 glands/cm².


Nepenthes rajah looks to flower at any time of the year. Flowers are bent in great numbers on inflorescences that rise from the top of the focal stem. Nepenthes rajah creates a very sizable inflorescence that can be 80 cm, and occasionally even 120 cm tall. The separate flowers of Nepenthes rajah are fashioned on partial peduncles (twin straws) and so the inflorescence is named a raceme (as opposite to a panicle for multi-flowered groups). The flowers are described to offer off a solid syrupy aroma and are brownish-yellow in color. Sepals are elliptic to parallelogram and ≤8 mm long. Like all Nepenthes species, N. rajah is dioecious, which means that separate plants create flowers of a single sex. Fruits are orange-brown and 10 to 20 mm long.

Other characteristics

Reproduction of Nepenthes Rajah
Nepenthes rajah feeds mainly on insects and small reptiles.

The root organization of Nepenthes rajah is particularly widespread, though it is moderately thin as in most Nepenthes species.

All parts of the plant are coated in lengthy, white hairs when young, but mature plants are virtually lack all sorts of hair. This cover of hair is identified as the indumentum.

The color of herbarium samples is dark-brown in variable sorts.

Little disparity has remained witnessed inside natural populations of Nepenthes rajah and, therefore, no types or variations have been defined. Additionally, Nepenthes rajah has no true nomenclatural synonyms, different from countless other Nepenthes species, which display bigger changeability.


Nepenthes rajah has continuously been believed to be one of the more problematic Nepenthes species to nurture. Though, in recent years, it has become seeming that the plant might not be justified of its status.

Environmental factors

Nepenthes rajah is a montane species or “highlander”, developing at heights reaching from 1500 to 2650 m. As such, it necessitates warm days, with heats reaching (preferably) from around 25 to 30 ℃, and cool nights, with temperatures of approximately 10 to 15 ℃. The temperatures themselves are not fundamental (when kept inside reasonable limits), but somewhat the temperature descent itself; Nepenthes rajah needs significantly cooler nights, with a drop of 10 ℃ or more being preferable. Failure to observe this requirement will almost certainly doom the plant in the long term or, at best, limit it to being a small, unimpressive specimen.

In addition, like all Nepenthes, this plant demands a relatively humid situation to grow well. Nepenthes rajah can bear oscillations in humidity, particularly when young, on condition that the air does not convert too dry. Humidity can be controlled without difficulty using an ultrasonic humidifier in combination with a humidistat.

In its usual habitat, Nepenthes rajah grows in exposed areas, where it is open to uninterrupted sunlight – it consequently requires to be kept with an important quantity of light in farming as well. To meet this need, many growers have used metal halide lamps in the 500–1000 watt range, with substantial success. The plant should be located a reasonable space from the light source, 1 to 2 m is recommended. Depending on location, growers can utilize natural sunlight as a source of illumination. However, this is only recommended for those living in equatorial regions, where light intensity is sufficient to satisfy the needs of the plant. A photoperiod of 12 hours is comparable to that experienced in nature, since Borneo lies on the equator.

Potting and watering

Untainted long-fiber Sphagnum moss is an outstanding potting medium, though mixtures concerning any of the following – peat, perlite, vermiculite, sand, lava rock, pumice, Osmunda fiber, orchid bark and horticultural charcoal – can be cast-off with identical accomplishment. The potting medium should be well-drained and not excessively compressed. Moss is beneficial for dampness retaining nearby the roots. The mixture should be methodically saturated in water previous to potting the plant.

It has been distinguished that Nepenthes rajah makes a very widespread root system (for a Nepenthes) and, for this reason, it is suggested that a broad pot be used to permit the correct growth of the root organization. This also eliminates the need for frequent re-potting, which can lead to transplant shock and the eventual death of the plant.

Purified water should be used for watering dedications, even though “hard water” is tolerated. This is done to reduce the build-up of minerals and chemicals in the earth. Water purity superior than 100 p.p.m. of total dissolved solids is frequently cited as idyllic. An inverse osmosis unit can be used to filter the water or, otherwise, bottled distilled water can be purchased. Watering should be done habitually. On the other hand, plants should not be allowed to sit in water, as this may lead to root rot.

Feeding and fertilizing

nepenthes rajah care
It is considered one of the most difficult to grow plants because it requires special care.

Nepenthes rajah is a carnivorous plant and, as such, additional nutrients added from the earth with captured prey (mainly bugs) to ease deficits in significant components such as nitrogen, phosphorus and potassium. Just as in nature, a nurtured plant’s “diet” may comprise bugs and other prey items, even though this is not essential for fruitful farming. Crickets are suggested for their size and low cost. These can be bought online or at expert pet stores. They can merely be released into the pitchers by hand or located inside using metal tongs or similar, whether dead or alive.

From tests passed out by a commercial Nepenthes nursery, it appears that micronutrient solutions have “a beneficial effect on plants of improved leaf coloration, with no deleterious effects” as far as can be appreciated. However, more investigation is obligatory to confirm these calculations. Actual fertilizers were, on the other hand, found to “cause damage to plants, promote pathogens and have no observable benefits”. Henceforth, the use of chemical fertilizers is typically not recommended.

Nepenthes rajah is a slow growing Nepenthes. Under optimal conditions, N. rajah can reach flowering size within 10 years of seed germination.

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