DUSKY PITCHER PLANT Nepenthes fusca
Nepenthes fusca, or the dusky pitcher-plant, is a tropical pitcher plant endemic to Borneo. It is found throughout a wide altitudinal range and is almost always epiphytic in nature, primarily growing in mossy forest.
The specific epithet fusca is derived from the Latin word fuscus, meaning "dark brown" or "dusky", and refers to the colour of the pitchers.
Nepenthes fusca is a climbing plant. The stem may attain a length of 10 m and is up to 8 mm in diameter. Internodes are circular in cross section and up to 7 cm long.
The leaves of this species are petiolate and coriaceous in texture. The lamina or leaf blade is obovate-oblong in shape and measures up to 15 cm in length by 6 cm in width. Tendrils measure up to 5 cm in length.
Rosette and lower pitchers are cylindrical throughout. They usually grow to 20 cm in height by 4 cm in width, although exceptional specimens up to 28 cm have been recorded. A pair of fringed wings (≤5 mm wide) runs down the ventral surface of the pitcher and bears fringe elements measuring up to 10 mm and spaced 6 mm apart.
Upper pitchers are similar in size to their lower counterparts, typically measuring up to 18 cm, with some larger forms reaching 26 cm. The pitcher lid is very narrowly triangular with the margins and apex curved downwards. In aerial pitchers, the wings are reduced to ribs.
Nepenthes fusca is most commonly found as an epiphyte in shady mossy forest on ridge tops, where it may grow 10 to 15 m off the ground. This makes it particularly difficult to find and often the only evidence of its presence are dead pitchers that have fallen to the forest floor.
Nepenthes fusca is classified as Vulnerable on the 2006 IUCN Red List of Threatened Species, based on an assessment carried out in 2000. This agrees with an informal assessment made in 1997 by Charles Clarke, who also classified the species as Vulnerable based on the IUCN criteria. However, Clarke noted that since substantial populations of N. fusca lie within the boundaries of national parks, they "are unlikely to become threatened in the foreseeable future.
Habitat destruction is considered to be the greatest threat to the species's survival in the wild. Plant poaching is of far lesser concern, as this species is not particularly sought after in the carnivorous plant hobby as its epiphytic habit makes it largely inaccessible to collectors.
Sacilotto found N. fusca to be tolerant of a wide range of conditions. Nepenthes fusca was found to tolerate temperatures in the range of 10 to 38 °C (50 to 100 °F). A nighttime drop in temperature below 21 °C (70 °F) was necessary for good growth; plants that were not exposed to such a drop grew poorly and produced fewer pitchers. The experiments suggested that N. fusca grows best when relative humidity is in the range of 65 to 90%.
The species seemed to do best in growing media with a high proportion of organic matter (such as a mixture consisting of 10% peat moss chunks, 30% perlite, and 60% of any combination of Sphagnum moss and fir bark). Soil with a slightly acidic pH of 4.5 to 5.0 produced the best results.
Nepenthes fusca was found to respond well to a quarter-strength fertilizer that was applied to the pitchers. Ants were also an effective food source.
Type: Tropical perennial
Hardiness zones: 9-11 planted outdoors, or grown indoors.
Seeds per pack: 5
Germination: These seeds germinate best on dampened sphagnum moss. Soak the moss for 1 hour, then gently squeeze out excess water, but allow some moisture to remain (not dripping). Place the moss in a container, and sprinkle the seeds on top. Cover the container with plastic to retain moisture. Place the container in very bright light, and in a very warm location, ideally 32C, 90F. Once the small plants begin to grow, slowly open the plastic a little each day. Use rain water or bottled water (use a spritz bottle while plants are small) to regularly water plants, but do not leave them standing on water. Once plants are large enough to transplant, a growing mix consisting of equal parts peat moss, perlite, vermiculite and sphagnum moss (long fibre type) can be used. Seeds germinate anywhere from 1 month, to 12 months. Patience is needed, but they are worth the effort for this unique plant!