Nepenthes orbiculata
Nepenthes orbiculata
118 vues
Taxonomie
| Famille: | Nepenthaceae |
|---|---|
| Genre: | Nepenthes |
| Commande: | Caryophyllales |
Aperçu
Nepenthes orbiculata is a lowland tropical pitcher plant known only from two sites in Phang Nga Province, Peninsular Thailand. Its lower pitchers are almost round, and for years it was grown and sold in Thailand under the informal name Nepenthes 'Viking'.
Nepenthes orbiculata is an upright shrub. Adult plants can reach 1.5 m, but in the wild the species is mostly found as rosettes with scrambling stems up to 50 cm long. The leaves are lanceolate, up to 25 cm long and 3-8 cm wide, sometimes with fringed margins, and the tendrils are two to four times as long as the pitchers.
The lower pitchers are ovoid to ellipsoid, 8-12 cm long and 5-7 cm wide, with two broad, fringed wings down the front. Their defining feature is the 'hip', the line where the pitcher's shape changes, which sits just below the lid. The peristome is flattened and 8-10 mm wide, and the lid is round to elliptic, with a small glandular boss on its underside near the tip. Lower pitchers are bright to dark red outside, often fading to pale green or white in the upper part, and pale green to white inside. Upper pitchers are 10-15 cm long, obconic to obovoid and light green. Plants may be hairless or entirely covered in a cobweb-like coat of hairs.
The species is closely related to N. mirabilis, which has more elongated pitchers with the hip at the centre or in the lower half. It is also close to N. mirabilis var. globosa from Trang Province, which can produce the same round pitchers but also elongated ones, and which climbs to 4 or 5 m. Catalano regards the round pitchers of the two as a case of convergent evolution in two separate populations of N. mirabilis exposed to the same monsoon climate and seasonal savanna habitat.
Informations géographiques
région natale: Phang Nga Province, Peninsular Thailand (endemic; two known sites)
Zones climatiques: Tropical lowland savanna (sea level); grown under glass outside the tropics
Sandy soils in savannas and grasslands at sea level. At both known sites, a few kilometres apart, it grows with N. andamana and N. mirabilis. Each takes a slightly different niche: N. mirabilis grows along the forest edge, N. andamana in the open savanna, and N. orbiculata in the waterlogged spots of the savanna. Near ponds and streams, N. mirabilis grows 0-1 m from the water and N. orbiculata 2-3 m from it.
Caractéristiques physiques
Taille adulte: Shrub to 1.5 m, usually a rosette with stems to 50 cm; lower pitchers 8-12 cm (3-5 in) long
Taux de croissance: Moderate
Type de piège: Pitfall Trap
Like other Nepenthes, each pitcher is a watertight trap at the tip of a leaf tendril. The ribbed rim around the mouth, the peristome, helps retain prey and guide it inside, and the pitcher's slippery walls make it very hard for an insect that has fallen in to climb out. The lid carries nectar glands that attract prey. In N. orbiculata the glandular (digestive) zone of the lower pitchers reaches almost to the base of the lid.
Guide d'entretien
Besoins en lumière
Bright, diffuse light. Artificial light can be enough if it is bright. In the wild it grows in open savanna.
Bright light year round tous les jours
Besoins en eau
Taper: Purified water (distilled, reverse osmosis or rain) is safest
Méthode: Water from above to keep the mix moist and let the excess drain. Plants left standing in trays often develop dwarfed root systems.
Fréquence: Often enough to keep the mix evenly moist
Humidité: High: at least 60%, ideally near 90%
Sol
A 50:50 mix of long-fiber sphagnum moss and perlite is a good general starting point. After about a year, check whether the roots are exploring the mix and change it if they are not.
pH: Acidic (sphagnum based)
Température
Été: Days 86-93°F (30-34°C), nights 14°F (8°C) cooler
Hiver: Same as summer (lowland tropical species)
Alimentation
Fréquence: Optional; fertilizer at most once or twice a month into pitchers
An orchid or epiphyte fertilizer can be poured into the pitchers once or twice a month, starting with small amounts and watching the effect. It is optional.
Propagation
Méthodes: Stem cuttings with about two leaves each, leaves trimmed to about a third, kept in very high humidity; roots usually form in about a month. Seed needs a male and a female plant flowering at the same time and should be sown immediately.
Difficulté: Moderate
Conseils pour débutants
Keep it warm, humid and brightly lit, water from the top, and buy from a source that can confirm it is N. orbiculata and not N. mirabilis var. globosa or a hybrid.
Dépannage
New leaves without pitchers or with burnt edges: humidity is too low. Weak, small root system: the pot has been standing in water. Pitchers with the hip lower down than usual: the plant may be immature, etiolated or a hybrid with N. mirabilis.
Conseils de culture
No pitchers? Raise the humidity Troubleshooting
When humidity is too low, leaf edges burn and tendrils fail to form pitchers. Raise humidity before changing anything else.
Warm and humid all year General
As a sea-level plant it wants days around 30-34°C (86-93°F), nights about 8°C (14°F) cooler, and humidity of at least 60%.
Check the hip of the pitcher Advanced
True N. orbiculata always has round lower pitchers with the hip just below the lid. Plants with the hip at the middle or lower are more likely N. mirabilis, N. mirabilis var. globosa or a hybrid.
Faits intéressants
The name orbiculata comes from Latin orbiculatus, 'round', after the shape of its pitchers.
Thai growers had it in cultivation from 1992, where it was nicknamed Nepenthes 'Viking'.
It is known from only two populations, a few kilometres apart.
At its sites the hybrid N. andamana × N. mirabilis makes up as much as a third of the local pitcher plants, and hybrids of N. orbiculata with both of those species are also frequent.
Its flowers have rarely been seen in the wild and are known mostly from photos and cultivated plants.
Immature, etiolated or hybrid plants can have lower pitcher hips, which makes them hard to tell from N. mirabilis var. globosa.
Histoire
In 2004 Marcello Catalano saw a cutting-grown plant with unusually squat, rounded pitchers at a stall in Chatuchak market, Thailand. The seller said it came from a secret island in Phang Nga Province. Thai growers told him the plant had been in cultivation in Thailand since 1992 under the nickname Nepenthes 'Viking', and the Japanese botanist Shigeo Kurata suggested publishing it as a new species, N. globosa. A similar round-pitchered plant from Trang Province, first collected by Hamilton and Congdon in 1979, complicated the picture.
In 2010 Catalano published the Trang plants as N. mirabilis var. globosa, treating both populations as one variety. Visits to Phang Nga colonies with Trongtham Kruetreepradit in 2013 showed that the round-pitchered plants grow alongside N. mirabilis and hybridize with it, while no round-pitchered colonies were known in the 200 km between Phang Nga and Trang. Catalano and Kruetreepradit concluded that the Phang Nga population was a separate species, and described it as N. orbiculata in 2018 in AIPC Magazine (issue 50), from a type specimen collected in 2017.
Sources
- Catalano, M. (2018). Nepenthes orbiculata, una nuova specie da Phang Nga (Thailandia). AIPC Magazine 50: 32-43 (archived PDF)
- Nepenthes orbiculata, Wikipedia
- Nepenthes: species from other parts of the world, The Carnivorous Plant FAQ (Barry Rice)
- Nepenthes: the tropical pitcher plants, The Carnivorous Plant FAQ (Barry Rice)
- Nepenthes: basic cultivation, The Carnivorous Plant FAQ (Barry Rice)
- Nepenthes: advanced cultivation, The Carnivorous Plant FAQ (Barry Rice)
Questions fréquentes
Disponible à l'achat
Espèces apparentées
Restez informé sur Nepenthes orbiculata
Abonnez-vous pour recevoir des conseils d'entretien, des guides de culture et des mises à jour spécifiques à Nepenthes orbiculata et d'autres plantes carnivores.