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28th Issue, Vol. 4, No. 1-B (Annex) ISSN 2094-1765 January 2011

A Closer Look at Philippine Pitcher Plants The Nepenthes, popularly known as tropical pitcher plants or monkey cups, are a genus of carnivorous plants in the monotypic family Nepenthaceae. The genus comprises roughly 130 species, numerous natural and many cultivated hybrids. They are mostly liana-forming plants of the Old World tropics, ranging from South China, Indonesia, Malaysia and the Philippines; westward to Madagascar and the Seychelles ; southward to Australia and New Caledonia ; and northward to India and Sri Lanka . The greatest diversity occurs on Borneo and Sumatra with many endemic species. Many are plants of hot humid lowland areas, but the majority are tropical montane plants, receiving warm days but cool to cold humid nights year round. A few are considered tropical alpine with cool days and nights near freezing. The name monkey cups refers to the fact that monkeys have been observed drinking rainwater from these plants. Description

Nepenthes species usually consist of a shallow root system and a prostrate or climbing stem, often several meters long and up to 15 m (49 ft) or more, and usually 1 cm (0.4 in) or less in diameter, although this may be thicker in a few species. From the stems arise alternate sword-shaped leaves with entire leaf margins. An extension of the midrib (tendril), which in some species aid in climbing, protrudes from the tip of the leaf; at the end of the tendril the pitcher forms. The pitcher starts as a small bud and gradually expands to form a globe- or tube-shaped trap. The trap contains a fluid of the plant's own production, which may be watery or syrupy and is used to drown the prey. Research has shown that this fluid contains viscoelastic biopolymers that may be crucial to the retention of insects within the traps of many species. The trapping efficiency of this fluid remains high, even when significantly diluted by water, as inevitably happens in wet conditions.

Basic structure of an upper pitcher

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The lower part of the trap contains glands which absorb nutrients from captured prey. Along the upper inside part of the trap is a slick waxy coating which makes the escape of its prey nearly impossible. Surrounding the entrance to the trap is a structure called the peristome (the "lip") which is slippery and often quite colorful, attracting prey but offering an unsure footing. Above the peristome is a lid (the operculum): in many species this keeps rain from diluting the fluid within the pitcher, the underside of which may contain nectar glands which attract prey. Nepenthes usually produce two types of pitchers, known as leaf dimorphism. Appearing near the base of the plant are the large lower traps, which typically sit on the ground. The upper or aerial pitchers are usually smaller, differently-coloured, and possess different features from the lower pitchers. These upper pitchers usually form as the plant reaches maturity and the plant grows taller. To keep the plant steady, the upper pitchers often form a loop in the tendril, allowing it to wrap around nearby support. In some species, different prey may be attracted by the two types of pitchers. This varied morphology also often makes identification of species difficult. Prey usually consists of insects, but the largest species may occasionally catch small vertebrates, such as rats and lizards. Flowers occur in racemes or more rarely in panicles with male and female flowers on separate plants. Seed is produced in a four-sided capsule which may contain 50–500 wind-distributed seeds, consisting of a central embryo and two wings, one on either side. Distribution and habitat

The global distribution of Nepenthes species.

The genus Nepenthes is mostly found within the Malay Archipelago, with the greatest biodiversity found on Borneo and Sumatra, especially in the Borneo montane rain forests. The full range of the genus includes Madagascar (N. madagascariensis and N. masoalensis), the Seychelles (N. pervillei), Sri Lanka (N. distillatoria), and India (N. khasiana) in the west to Australia (N. mirabilis, N. rowanae, and N. tenax) and New Caledonia (N. vieillardii) in the southeast. Most species are restricted to very small

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ranges, including some that are only found on individual mountains. These limited distributions and the inaccessibility of the region often means that some species go decades without being rediscovered in the wild (e.g. N. deaniana, which was rediscovered 100 years after its initial discovery). Approximately ten species have population distributions larger than a single island or group of smaller islands. Nepenthes mirabilis has the distinction of being the most widely distributed species in the genus, ranging from Indochina and throughout the Malay Archipelago to Australia. Because of the nature of the habitats which Nepenthes species occupy, they are often graded as either lowland or highland species, depending on their altitude above sea level, with 1,200 m (3,937 ft) the rough delineation between lowland and highland. Species that grow at lower altitudes require continuously warm climates with little difference between day and night temperatures, whereas highland species thrive when they receive warm days and much cooler nights. Most Nepenthes species grow in environments that provide high humidity and precipitation and moderate to high light levels. A few species, prefer the dense, shaded forests, but most other species thrive on the margins of tree/shrub communities or clearings. Some species have been found growing in clear-cut forest areas, roadsides, and disturbed fields. Other species have adapted to growing in savanna-like grass communities. The soils that Nepenthes grow in are usually acidic and low in nutrients, being composed of peat, white sand, sandstone, or volcanic soils. There are, however, exceptions to these generalities, including species that thrive in soils that have high heavy metal content, on sandy beaches in the sea spray zone. Other species grow on inselbergs and as lithophytes, while others, can grow as epiphytes with no soil contact. Ecological relationships The most obvious interaction between Nepenthes species and its environment, including other organisms, is that of predator and prey. Nepenthes species certainly attract and kill their prey, albeit passively, through active production of attractive colors, sugary nectar, and even sweet scents. From this relationship, the plants primarily gain nitrogen and phosphorus to supplement their nutrient requirements for growth, given that soil nutrients are typically lacking. The most frequent prey is an abundant and diverse group of arthropods, with ants and other insects topping the menu. Other arthropods that are found frequently include spiders, scorpions, and centipedes, while snails and frogs are more unusual but not unheard of. The most uncommon prey for Nepenthes species includes rats found in N. rajah. The composition of prey captured depends on many factors, including location, but can incorporate hundreds of individual insects and many different species. While many Nepenthes are generalists in what they capture, at least one, N. albomarginata, has specialised and almost exclusively traps termites and produces nearly no nectar. Nepenthes albomarginata gains its name from the ring of white trichomes that are directly beneath the peristome. These trichomes—or "hairs"—are palatable to termites and will attract them to the pitcher. In the course of collecting the edible trichomes, hundreds or thousands of termites will fall into the pitcher. Cultivation Nepenthes may be cultivated in greenhouses or in a garden where humidity could be somehow controlled. Lowland species are usually easier to grow than that of highland species.

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Highland forms are those species that grow in habitats that are generally higher up in elevation, and thus exposed to cooler evening temperatures. Lowland forms are those species that grow nearer to sea level. Both forms respond best to rainwater (but tap water works as long as you flush it out with rainwater every month or if you have soft water), bright light (not full sun), a well drained medium, good air circulation and relatively high humidity, although easier species such as N. alata can adapt to lower humidity environments. Highland species must have night-time cooling to thrive in the long-term. Chemical fertilizers are best used at low strength. Occasional feeding with frozen (thawed before use) crickets may be beneficial. Terrarium culture of smaller plants is possible, but most plants will get too large over time. Plants can be propagated by seed, cuttings, and tissue culture. Seeds are usually sown on damp chopped Sphagnum moss, or on sterile plant tissue culture media once they have been properly disinfected. The seeds generally become nonviable soon after harvesting, so seed are not usually the preferred method of propagation. A 1:1 mixture of orchid medium with moss or perlite has been used for germination and culture. Seed may take two months to germinate, and two years or more to yield mature plants. Cuttings may be rooted in damp Sphagnum moss in a plastic bag or tank with high humidity and moderate light. They can begin to root in 1–2 months and start to form pitchers in about six months. Tissue culture is now used commercially and helps reduce collection of wild plants, as well as making many rare species available to hobbyists at reasonable prices. Nepenthes are considered threatened or endangered plants and are listed in CITES appendices 1 & 2. Some of the Philippine Pitcher Plants

Nepenthes alata Nepenthes argentii

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Nepenthes attenboroughii Nepenthes bellii

Nepenthes burkei Nepenthes copelandii

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Nepenthes deaniana Nepenthes gantungensis

Nepenthes hamiguitanensis N. mantalingajanensis

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Nepenthes merrilliana Nepenthes micramphora

Nepenthes mindanaoensis Nepenthes mira

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Nepenthes mirabilis Nepenthes palawanensis

Nepenthes petiolata Nepenthes philippinensis

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Nepenthes. sibuyanensis Nepenthes surigaoensis

Nepenthes truncata Nepenthes ventricosa

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Pitcher plants are one type of carnivorous plants which can be successfully grown in your garden. Carnivorous plants are properly called “insectivorous plants”, as they prefer to trap insects, and are not like the imaginary notion of a flesh-hungry creeping plant monsters. One common species is Nepenthes alata, which is found in Philippine forests and also widespread within the southeast Asian region. The genus name Nepenthes came from the Greek words: ne, meaning “not” and penthos, “grief:, meaning “without grief” as it was mentioned in Homer’s Odyssey in which the plant was given to Helen by an Egyptian queen as a drug that quells all sorrows with forgetfulness. Pitcher plants are certainly wonderful botanical specimen plants to behold, with its colorful and strange pitcher-like, insect trapping appendages. Pitcher plants are locally called Pitsel-Pitselan in Tagalog, Condom plants or Monkey Cups (as plant collectors see monkeys occasionally drinking the fluid in the pitchers). The plant group which belongs to the Nepenthaceae plant family, is composed of about 120 species of vine-forming plants, distributed in South China, Indonesia, Malaysia, the Philippines, Madagascar, the Seychelles, Australia, New Caledonia, India and Sri Lanka. Nepenthes are shallow rooted prostate or climbing vines, and may attain a length of about several meters long. Leaf-like expanded petioles arises from the stem, ending in a tendril, which aids the plant in climbing. The pitcher, which is considered its true leaf, forms at the end of the tendril. The pitcher is actually a leaf modification and are swelling of the mid-vein in the leaf. Insects are attracted to this structure because of the nectar secretions and coloration. Pitchers ranges in size and color of green, yellow and red. This leaf modification is an insect trap and supplies the plant with added nourishment from insects prey as the plant thrives in nutrient deficient locations. Prey are not totally limited to insects, as some large species of pitcher plants can trap rats and lizards. The insect traps contain a fluid, either watery or syrupy, and is manufactured by the plant itself. The fluid is slippery in consistency to prevent the escape of the prey and is intended to drown the prey. The trapping efficiency of this fluid remains high, even when significantly diluted by rain water. The lower portion of the trap contains glands which absorb nutrients from the dead decaying prey. Along the upper inside part of the trap is a slick waxy coating which makes the escape of its prey nearly impossible. The slippery rim (peristome or “lip”) is slippery and colorful, offering unsure footing, and attracting insects to fall into the digestive fluid at the bottom of the trap. Trapped insects are actually drowned and nutrients are absorbed from this “soup”. Above the peristome is a lid (operculum), which in most species keeps the rain from diluting the fluid within the pitcher, the underside of which may contain nectar glands used as a bait for prey. Cultural Requirements for Pitcher Plants: Light – Pitcher plants grows in diffused bright light (about 50% light). Protect it from direct sun, . to avoid scorching of leaves. They can be grown with other shade loving orchids like Phalaenopsis and ferns. Watering & Humidity – Water plants regularly and do not allow them to dry out completely. They can benefit from moist media and occasional flooding to wash away any accumulated salts. Use soft water such as rain water, distilled or purified water. Tap water can be used as long as the water is low in salts. Low level chlorine does not seem to be problem. Provide a humid environment by grouping Pitcher plants along with other shade loving plants and watering them regularly. They usually stop making pitchers when humidity is low. They can also be grown in terrariums (the small species), or inside clear plastic bags for added humidity. Allow ventilation and air-movement between plants at all times to prevent rotting of leaves. As much as possible, always add a little water to the pitchers, about ½ or ¾ its length to avoid drying up.

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The Urban Gardener is an official electronic publication (in PDF Format) of the Plant Biotechnology Project, Research & Dev’t. Center, Rizal Technological University, Boni Avenue, Mandaluyong City, Philippines. It is published monthly. For more information, please inquire thru email: rdc_rtu@yahoo.com or plantbiotech_rtu@yahoo.com and landline (+632) 534-8267 Local 135 or Fax (+632) 534-9710.

Edited by N.R. Bautista © January 2011

The Plant Biotechnology Project Committee is composed of: Alexander B. Quilang, Norberto R. Bautista, & Jovita A. Anit.

Temperature. Nepenthes are grouped into the low-land species and the high-land species. Lowland types are more tolerant to lower humidity, warmer conditions and are usually easier to grow than the highland types. The highland types prefer a much cooler night time temperature and higher humidity. Potting Technique – Plant pitcher plants in plastic pots with any porous and low-fertility mixes like mixture of charcoal, coconut husk cubes, sphagnum moss, tree fern fiber and paslak (chopped roots of Birds nest fern). The media should be well drained and open enough so that air reaches the roots. Repot if the media breaks down, or when the plants needs a bigger pot. They are usually potted as a hanging plant. Tapping or vibrating the pot is a good way to settle down the media around the roots, but avoid pushing the media down as it can damage the plants’ fine roots. Water well after repotting. Fertilization. Pitcher plants are light feeders. It is not recommended to use control release fertilizers in the pots as it may burn the roots. If plants are being grown on areas where they cannot trap insects, spraying of very dilute balanced orchid fertilizer, about 1/8 teaspoon per galloon water once every week is sufficient. Another way is to add the fertilizer solution in its pitchers at about ¾ filled. For most plant hobbyists, one can occasionally add a small insect such as a fly, a cockroach or a dead cricket into the mature pitchers, however this is not normally needed. Pruning. Pitchers and leaves die naturally as the plant grows. Dead or dried parts need to be trimmed off. Nepenthes are vines, thus it is suggested that green stems be pruned back to encourage side shoots and to produce fuller plants, however, avoid pruning off more than 30 % of its foliage. Vines can be trained up on stakes, on wires or in hanging baskets. If plants fail to produce pitchers, increase humidity. Pest & Diseases. Most plants has not much pest. However, if insect infestation occurs, spray with a dilute solution of insecticide like Malathion or Lannate. To prevent leaf spots, allow ventilation among plants, allow proper spacing and keep plants dry between watering. For outbreak of fungal diseases, spray with a weak solution of Captan or Dithane. Propagation. In nature, pitcher plants are propagated by seeds. Male and female flowers are borne on racemes or in panicles on shoot tips of separate plants. Winged seeds numbering 10-60 or more are produced in four-sided capsules and they are dispersed by wind. Seeds may be sown on damp chopped sphagnum moss or in sterile plant tissue culture media (similar to how orchids are mass produced). Seeds generally become non-viable soon after harvesting, thus, seeds are not actually the preferred mode of propagation. Another way is to use shoot tip cuttings and they maybe rooted in damp sphagnum moss in a clear plastic bag or enclosed in a covered aquarium tank with high humidity and moderate lighting. Cuttings start to root in 1-2 months, and can start to form pitchers after 6 months. Plant tissue culture technology is now used in the commercial mass propagation of selected Nepenthes species and this helps to reduce the direct collection of plants from the wild. Efficient propagation techniques also makes rare species available and affordable to plant hobbyists and collectors. Conservation is needed for this group of plants as Nepenthes are considered threatened or endangered and are listed in Appendix 1 and 2 of CITES.