Nepenthes rafflesiana
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Nepenthes rafflesiana |
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Nepenthes rafflesiana is a carnivorous plant from the genus of pitcher plants ( Nepenthes ). It is native to Borneo, Sumatra and the Malay Peninsula.
description
Nepenthes rafflesiana is a perennial, evergreen , climbing subshrub that can often be up to 4, rarely up to 15 meters high.
Nepenthes rafflesiana forms short shoots , the leathery, stalked leaves of which are spread out. The 2 to 10 centimeters long petiole is furrowed and narrowly winged, at its base it encloses the stem like a leaf sheath from half to two thirds. The lanceolate-spatulate blade , rounded at the tip to tapering to a point and sometimes suddenly tapering towards the base, becomes 8 to 30 centimeters long and 1.5 to 5 centimeters wide. From the petiole arise three to five longitudinally parallel ribs, the numerous side ribs run diagonally to the edge. The leaf veins are irregularly reticulated. The tendrils are as long or slightly longer than the blade, bent down or drooping and without curls.
The leaves of the long shoots are similar to those of the short shoots, they differ through an elongated-round to lanceolate leaf shape, are 12 to 30 centimeters long and 3 to 10 centimeters wide, usually blunt towards the tip, rarely tapering to a point. The petiole is half as long to as long as the blade. Four or five longitudinal side ribs arise from the approach of the central rib and run parallel in the outer two thirds of the blade. The tendrils are usually longer than the rungs, can-bearing tendrils form a curl.
The pitchers show a clear dimorphism . The so-called floor jugs are rounded in the lower part and become conical towards the top . They are 5 to 25 inches high and 3 to 10 inches wide at the bottom. Two fringed wing strips up to 35 millimeters wide run along the entire length. The individual fringes are thread-shaped, up to 15 millimeters long and are spaced 0.5 to 3 millimeters apart. The jug opening is steeply inclined and extends into a 2 to 5 centimeter long transition to the jug lid. The peristome is flattened, the ribs are 0.5 to 1 millimeter apart, the teeth on the inner edge are three to six times as long as they are wide. Up to two thirds of its height, the surface of the inside of the pitcher is covered with 1,800 to 2,500 tiny, bulging glands per square centimeter. The lid is egg-shaped to heart-shaped and - most of all at the base - arched. There are a few thread-like appendages on the top. In the center the lid is glandless, towards the edge it has numerous, relatively large, sunken glands. The spur close to the lid is unbranched and up to 20 millimeters long. The top pitchers, i.e. those of the long shoots, are similar to the bottom pitchers, but 10 to 40 centimeters high and 3 to 6.5 centimeters wide at the top. The can opening is very steep. The peristome is flattened and rolled up on the outer edge. The inside is completely covered with glands. The lid is 5 to 10 inches long and 3.5 to 8 inches wide.
The male inflorescences are cylindrical racemes . The inflorescence is 6 to 18 centimeters, the inflorescence axis 10 to 50 centimeters long, at the base it measures 3 to 5 millimeters in diameter. The flower stalks are single-flowered, rarely double-flowered, without bracts , the lower 10 to 25 millimeters long, the upper slightly shorter. The bracts are oblong-round to elliptical, 4 to 10 millimeters long, the anthers are in one or two whorls . The female inflorescences are similar to the male ones, they are only slightly shorter. The ovary is strongly tapered at its base to almost a stalk. The fruit is strongly tapered at the base, 25 to 50 mm long and 4 to 8 millimeters wide. The seeds are thread-shaped and contain tiny, spindle-shaped seeds 10 to 20 millimeters in length.
The number of chromosomes is 2n = 80.
ecology
To attract prey, the pitchers have strong UV patterns, especially on the peristome, which are particularly noticeable to insect eyes. Around 20% of the pitchers also produce fragrances, which means that they attract almost twice as much prey as pitchless pitchers. There may also be a case of Batesian mimicry in the air cans , imitating flowers.
All of these properties mean that Nepenthes rafflesiana is one of the species with the broadest prey range of all pitcher plants. Their prey comes from three classes ( insects , arachnids , centipedes ) and fifteen orders , with ants accounting for 88.7% in ground cans and 64.3% in air cans, followed by 7.3% in termites and in air cans of 19.1% two-winged birds . The jug liquid in particular is decisive for success: the movement of the animals in the liquid makes it extremely visco-elastic , so that escape is no longer possible.
The Hardwick woolly bat Kerivoula hardwickii uses the large pitchers of Nepenthes rafflesiana as a low-parasite overnight accommodation. The plant also benefits from the nutrients from the animal's droppings.
Distribution and habitat
Nepenthes rafflesiana is widespread in Borneo at altitudes between sea level and 1000 meters , but rarely in Sumatra , on the Malay Peninsula and in Singapore . It grows in open vegetation on swampy soils to shady forests, it is often found on roadsides in herbaceous growth.
Systematics
Nepenthes rafflesiana was first described by William Jack in 1835, the specific epithet honoring Thomas Stamford Raffles , the founder of Singapore . Confusingly, Hugh Low also described a Nepenthes under this name in 1848 . His name is invalid, the species was renamed as Nepenthes hookeriana in the sense of Low, but has since turned out to be a natural hybrid of Nepenthes rafflesiana with Nepenthes ampullaria ( Nepenthes × hookeriana ).
Due to the extreme variability of the species, numerous varieties and forms have been described, especially from Borneo , all of which are now considered synonymous.
Individual evidence
- ↑ a b c d e f Benedictus H. Danser : The Nepenthaceae of the Netherlands Indies. = Contributions à l'étude de la flores des Indes Néerlandaises. XV. In: Bulletin du Jardin de Botanique. Series 3, Vol. 9, No. 3–4, 1928, ISSN 0852-8756 , pp. 249–438, ( Nepenthes rafflesiana - text online )
- ^ Nepenthes rafflesiana at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- ^ A b Jonathan A. Moran: Pitcher dimorphism, prey composition and the mechanism of prey attraction in the pitcher plant Nepenthes rafflesiana in Borneo. In: Journal of Ecology . Vol. 84, No. 4, 1996, pp. 515-525, JSTOR 2261474 .
- ↑ Laurence Gaume, Yoel Forterre: A Viscoelastic Deadly Fluid in Carnivorous Pitcher Plants. In: PLoS ONE . Vol. 2, No. 11, 2007, e1185, doi : 10.1371 / journal.pone.0001185 .
- ↑ T. Ulmar Grafe, Caroline R. Schöner, Gerald Kerth, Anissa Junaidi, Michael G. Schöner: A novel resource-service mutualism between bats and pitcher plants. In: Biology Letters . Vol. 7, No. 3, 2011, doi : 10.1098 / rsbl.2010.1141 .
- ^ A b c Matthew Jebb, Martin Cheek: A Skeletal Revision of Nepenthes (Nepenthaceae). In: Blumea. Vol. 42, 1997, ISSN 0006-5196 , pp. 1–106, here pp. 75–76, ( digital version (PDF; 8.82 MB) ).
- ↑ Megan R. Crawford: Structure and Dynamics in Nepenthes Pitcher Plants of Borneo , 2007, p. 6, ( PDF Online ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link accordingly Instructions and then remove this notice. )
