Fanged Pitcher Plant

Taxonómia

Rodina:	Nepenthaceae
Rod:	Nepenthes
Objednávka:	Caryophyllales

Prehľad

Nepenthes bicalcarata, the fanged pitcher plant, is a giant lowland vine endemic to Borneo. Two sharp thorns hang above the mouth of each pitcher, and its hollow tendrils house a species of ant, Camponotus schmitzi, that lives in partnership with the plant.

Nepenthes bicalcarata is the largest plant in the genus, climbing up to about 20 m into the forest canopy on a stem up to 3.5 cm thick, thicker than that of any other species. Its leathery leaves reach 80 cm long and 12 cm wide, and the tendrils grow up to 60 cm long. The tendrils are hollow and swollen near the pitcher, and are the main home of its ants.

The pitchers themselves are not the largest in the genus, but they can hold over a litre and grow up to 25 cm (10 in) tall and 16 cm wide. Lower pitchers carry a pair of prominent fringed wings, which are usually reduced to ribs on upper pitchers. The peristome is flattened and curved inwards, and its uppermost 10 to 12 ribs are fused into the two thorns that give the species its name; they may be 3 cm long. The lid is kidney- to heart-shaped and broader than long. Lower pitchers range from green to red, while upper pitchers are usually yellowish or orange, sometimes green.

Mature plants are almost hairless. The species varies little across its range and no varieties have been described. Natural hybrids are known with N. ampullaria, N. gracilis (N. × cantleyi), N. mirabilis and N. rafflesiana, but none is known to be colonised by the ants.

Geografické informácie

Rodný región: Borneo (endemic): northwestern Kalimantan, Sarawak, Brunei and southwestern Sabah

Klimatické zóny: Tropical lowland, mostly below 300 m

Nepenthes bicalcarata is most common in the peat swamp forests of western Borneo, where it often grows in the shade of the dipterocarp tree Shorea albida. It also occurs in kerangas (heath) forest on white sand, and is often found alongside N. ampullaria. Plants grow largest in undisturbed swamp forest, where the light is diffuse and the humidity high. Its roots are shallow, reaching only about 25 cm into the peat and leaf litter, because the deeper peat is made toxic by tannins and alkaloids. It is generally found below 300 m; Cheek and Jebb give its full range as sea level to 950 m.

Fyzikálne vlastnosti

Veľkosť pre dospelých: Vine climbing to about 20 m; pitchers up to 25 cm (10 in) tall

Tempo rastu: Fast

Typ pasce: Pitfall Trap

The two thorns under the lid carry some of the largest nectaries in the plant kingdom. Their purpose has long been debated: Frederick Burbidge suggested they deter mammals from raiding the pitchers, but Charles Clarke's observations suggest they lure insects into a precarious position over the mouth, from which they slip into the fluid. The peristome matters too: a 2004 study found that a wet peristome catches more than three times as many insects as a dry one. As in N. ampullaria, the digestive zone reaches almost to the rim, leaving little or no waxy zone.

The plant is also fed by its ants. Camponotus schmitzi nests only in its tendrils, swims in the pitcher fluid, hauls large prey out and eats fly larvae that would otherwise leave the pitcher, and the plant absorbs nutrients from the ants' waste. This input has been estimated at 42% of the plant's leaf nitrogen, and 76% in heavily occupied plants. The ants also clean the peristome and defend the plant against pitcher-destroying weevils. In return the plant keeps its fluid less acidic and less sticky than most Nepenthes and appears to lack functional digestive enzymes, so it depends heavily on the ants.

Sprievodca starostlivosťou

Požiadavky na svetlo

In the wild it grows largest in diffuse light under the swamp-forest canopy. Bright, diffuse light is excellent, and artificial lighting can be adequate if it is bright enough.

Bright light year round; no seasonal rest denne

Požiadavky na vodu

Typ: Purified water (distilled, reverse osmosis or rain) is safest

Metóda: Water from above and let the excess drain. Do not keep the pot standing in a tray of water: plants sitting in trays often have dwarfed root systems.

Frekvencia: Often enough to keep the mix evenly moist

Vlhkosť: Very high: at least 60%, ideally near 90%

Pôda

A 50:50 mix of long-fiber sphagnum moss and perlite is a good general starting point. After about a year, knock the plant out of its pot and look at the roots; if they are not exploring the mix, try a different one. Although it grows wild in peat swamp, N. bicalcarata has also been grown successfully in a fully inorganic mix of clay granules and lava gravel.

pH: Acidic (sphagnum based)

Teplota

Leto: Days 86-93°F (30-34°C), nights about 14°F cooler

Zima: Same as summer; tropical, grows all year

Kŕmenie

Frekvencia: Optional; at most once or twice a month into the pitchers

In the wild a large part of its nitrogen comes from its resident ants rather than its own digestion. Plants that catch insects need no feeding. Growers who want to fertilize can pour a small amount of orchid or epiphyte fertilizer into the pitchers once or twice a month, starting small and watching the effect. Fertilizing is optional.

Šírenie

Metódy: Stem cuttings: cut green stems into segments with about two leaves each, trim each leaf to about a third of its size, set the lower half in the mix and keep the cutting at very high humidity. Roots usually form within about a month. Seed needs a male and a female plant flowering at the same time; it is short-lived and should be sown at once.

Náročnosť: Moderate

Tipy pre začiatočníkov

Give it more heat, humidity and pot space than most Nepenthes, and be prepared for a large plant: under good conditions it grows fast.

Riešenie problémov

Growth stops for a while: the plant is often root-bound, and moving it to a larger pot often brings a rapid increase in size. Leaf edges burning and tendrils failing to form pitchers: humidity too low. A small plant with a weak root system: the pot has been standing in water.

Tipy na pestovanie

Room to grow Advanced

This is the largest Nepenthes and grows quickly for the genus when conditions suit it. Plan for a big plant.

Hot and humid General

As a lowland plant it wants days around 86-93°F (30-34°C), nights only about 14°F (8°C) cooler, and very high humidity.

Give it a big pot Troubleshooting

Pauses in growth are often caused by the plant becoming root-bound. Repotting into a larger pot often brings a rapid increase in size.

Zaujímavé fakty

Bicalcarata means 'two-spurred', after the two thorns over the pitcher mouth.
It is the largest Nepenthes, with the thickest stem of any species.
Its ant partner, Camponotus schmitzi, can swim and stay submerged in the pitcher fluid for up to 30 seconds.
Hauling one prey item about 5 cm out of the fluid may take the ants up to 12 hours.
A mite, Naiadacarus nepenthicola, appears to live only in its pitchers and hitches rides on the ants.
In Veitch's 1889 catalogue it cost more per plant than the famous N. rajah.
The IUCN Red List lists it as Vulnerable, from a 2000 assessment (Schnell et al., assessment T39624A10252393).

História

Joseph Dalton Hooker described Nepenthes bicalcarata in 1873, from specimens collected by Hugh Low and Odoardo Beccari near the Lawas River in Borneo; the type is held at Kew. In 1880 Spencer Moore described N. dyak from western Borneo, now treated as the same species.

Frederick William Burbidge, collecting for the Veitch Nursery, introduced it to Europe in 1879, and Veitch distributed plants in 1881, when interest in Nepenthes was at its peak. Burbidge also noted its ant partnership as early as 1880. It remained a horticultural rarity for years: in 1889 Veitch priced it at £3 3s a plant, against £2 2s for N. northiana and N. rajah. Artificial hybrids include the cultivars 'Hortulanus Otten' (with N. hirsuta) and 'Nina Dodd' (with N. × dyeriana).

Zdroje

Často kladené otázky

In the wild it grows largest in diffuse light under the swamp-forest canopy. Bright, diffuse light is excellent, and artificial lighting can be adequate if it is bright enough. Cieľom je asi Bright light year round; no seasonal rest svetla za deň.

Purified water (distilled, reverse osmosis or rain) is safest. Water from above and let the excess drain. Do not keep the pot standing in a tray of water: plants sitting in trays often have dwarfed root systems.

A 50:50 mix of long-fiber sphagnum moss and perlite is a good general starting point. After about a year, knock the plant out of its pot and look at the roots; if they are not exploring the mix, try a different one. Although it grows wild in peat swamp, N. bicalcarata has also been grown successfully in a fully inorganic mix of clay granules and lava gravel. pH pôdy: Acidic (sphagnum based).

Nepotrebuje spánok. Zimné teploty: Same as summer; tropical, grows all year.

In the wild a large part of its nitrogen comes from its resident ants rather than its own digestion. Plants that catch insects need no feeding. Growers who want to fertilize can pour a small amount of orchid or epiphyte fertilizer into the pitchers once or twice a month, starting small and watching the effect. Fertilizing is optional. Ako často: Optional; at most once or twice a month into the pitchers.

Borneo (endemic): northwestern Kalimantan, Sarawak, Brunei and southwestern Sabah. Nepenthes bicalcarata is most common in the peat swamp forests of western Borneo, where it often grows in the shade of the dipterocarp tree Shorea albida.

V Červenom zozname IUCN je zaradený ako Vulnerable.

Stem cuttings: cut green stems into segments with about two leaves each, trim each leaf to about a third of its size, set the lower half in the mix and keep the cutting at very high humidity. Roots usually form within about a month. Seed needs a male and a female plant flowering at the same time; it is short-lived and should be sown at once.

Growth stops for a while: the plant is often root-bound, and moving it to a larger pot often brings a rapid increase in size. Leaf edges burning and tendrils failing to form pitchers: humidity too low. A small plant with a weak root system: the pot has been standing in water.

Carnivoras sells Fanged Pitcher Plant in Mexico. See the plants available on this page.