pitcher plant
Generic name
for a tropical
carnivorous plant of the genus Nepenthes, of which there exist
many species, as well as several hybrids and cultivars. They are mostly found
within the Malay-Indonesian Archipelago, including the Philippines, with the
greatest biodiversity found on the islands of Borneo (fig.) and Sumatra. Outside this region they are
also found in Madagascar, India, Sri Lanka, southern China and northern
Australia, but to a lesser extend. The species found in Thailand include Nepenthes anamensis, Nepenthes ampullaria, Nepenthes globosa, Nepenthes gracilis,
Nepenthes mirabilis (fig.), Nepenthes sanguinea, Nepenthes smilesii, and Nepenthes
thorelii. Pitcher plants derive their name from the plant's globe- or
tube-shaped trap, that resembles a pitcher with a lid and is used to capture
prey. This pitcher contains either a watery or viscous fluid which is produced
by the plant itself and used to drown its prey. On the inside, the lower part of
the pitcher contains glands that absorb nutrients from captured prey, whilst the
upper part has a slick waxy coating which impedes the escape of any prey. The
upper edge of the pitcher's mouth has a curled lip, called the peristome, which
is very slippery. This peristome is often quite colourful, which attracts prey,
but offers an unsure footing. Above the peristome is a lid known as the
operculum, which in many species contains nectar glands on the underside, in
order to attract prey. In addition, the lid may help prevent the fluid within of
being diluted by rain, though this would hardly affect its efficiency. Despite
its lethal features, there are some organisms that may spend at least part of
their lives within the pitchers and in return aid the plant with its digestion.
These natural tenants are called infauna. Besides this, many pitcher plant
species have also formed a dependant relationship with visiting insects and
vertebrates. Carpenter ants take larger prey from the pitchers of the Fanged
Pitcher-Plant (Nepenthes bicalcarata) found in Borneo and build their nests in
the hollow tendrils of its upper pitchers, thus reducing potential harmful
organic matter for the community of infaunal species. In order to avoid any
pollinating insects to also fall prey, pitcher plants grow their flowers well
away from their pitcher traps. The Low's Pitcher-Plant
(Nepenthes lowii), another species endemic to Borneo has relatively large
pitchers, that grow up to 28 centimeters high and 10 centimeters wide. The lids
of these pitchers provide a sugary nectar which is eaten by tree shrews, that
perch on and defecate into the pitcher, which led to this species being
nicknamed tree shrew lavatories. Pitcher plants are also known as common swamp
pitcher plants, as well as monkey cups, and are in Thai generally
called moh
khao
moh
kaeng ling (หม้อข้าวหม้อแกงลิง), which could be translated
as ‘monkey
rice pot soup pot’, though each species also has its own specific
Thai designation, with
Nepenthes mirabilis being called kha-neng nai phraan (เขนงนายพราน). The name monkey cups refers to the fact that monkeys have
reportedly been
observed drinking rainwater from these plants, whereas the Thai name rice pot
derives from the fact that the people in Southern Thailand steam rice in the
pitchers. See also
ton mai kin malaeng.
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