P. grandiflora: hardy, lime-tolerant, rockery or pond edge, easy (see pp.29 and 64).
P. vulgaris: hardy, purple flowers, peat bog, not easy. P. moranensis group: large, easy indoors in indirect light or shade (see pp.6 and 62).
P. agnata: large, indoors, white flowers tinged purple at edge. P. gypsicola: needs care, very beautiful leaves and flowers. P. primuli/Jora: keep warm, leaves grow new plants at ends.
A relative of Sarracenia, D. cali/ornica is another pitcher plant from North America and the sole representative of its genus. As the name implies, it is a native of California, where it grows in the mountains along the mossy banks of streams.
With its startling cobra-like appearance, which gives it the common name of cobra lily, this plant certainly deserves to be better known to most gardeners. The pitcher trap works in a very similar way to Sarracenia, but looks different, the entire pitcher length being twisted and the head forming an expanded hood with snake-like fangs at the mouth. Nectar on the hood and fangs attracts the prey, which enters the hood through a hole. Although it might still be able to escape at this stage, it is usually lured further into the hood and away from the true exit, towards the light admitted by transparent cells or false windows. Exhaustion or sheer bad luck leads the fly on into the slippery pitcher neck, from where there is almost no hope of escape.
The mottled green traps may continue to be attractive and possibly useful for two to three years. Each season the new traps tend to be bigger than those of preceding years, the very first pitcher of the year being the largest. As with Sarracenia, the flowers appear before the pitchers in spring and are tall pendulous lanterns of greenish yellow and brick-red. Although the petals fall within a few weeks, the seed heads remain decorative for months and also dry well.
In the wild, Darlingtonia survives snow cover, but Californian winters are relatively mild and dry. Therefore, it is wise to provide winter protection, either under glass or outside with a covering of loose straw. In summer, a cool root run is essential and plants should be kept in semi-shade outdoors, where they will happily grow in a bog or pond. Alternatively, they may be potted and stood in water, preferably submerging the roots and crown and in winter reducing the depth of water to about 2 in. (5 cm). Compost: D or B. Temperature: 32°F (0°C) winter minimum or protect with straw.
New plants produced around the edges of the pot can simply be separated and repotted.
The third type of pitcher plant, C./olIicularis, is the only member of its genus and is confined to a small area of western Australia near the town of Albany.
To see this little plant, never more than 2\ in. (6cm) tall, is to want to own one. It nestles in a bed of moss, forming a tight clump of open-mouthed pitchers, green in normal light or purple in strong sunshine, with leaves which are more or less numerous depending on the season. Each pitcher is like a miniature, thumbless, boxing glove, with a cap overhanging the opening and three obvious hairy ribs on the main body, as well as a smoothly ribbed rim. These ribs almost certainly help to guide insects, chiefly ants and beetles, into the trap. Nectar is also secreted as a lure. As with Darlingtonia, the trap is spotted with windows which admit light, although their exact purpose or even whether they have a role in trapping is not clear. Whatever the explanation, Cephalotus is a strange, lovable, but much understudied plant. Traps are produced in the summer months and plain, slightly fleshy leaves in spring. The flower spikes are an incredible 2 ft (60 cm) tall, but of no particular beauty.
The plant does best in a very open compost and care should be taken that it is not overgrown by tall mosses. It should stand in a tray or deeper container of soft water all year. Strong sunlight is essential for the best growth and colouration. Compost: B. Temperature: 50°F (10°C) winter minimum (see pp.31 and 59).
Easily increased by division, root cuttings or leaf cuttings. NEPENTHES MONKEY CUP
Probably the most familiar pitcher plants of all are the tropical Nepenthes, known as monkey cups. Although few people have seen them alive, they are popular subjects for magazines and television and in Victorian times were common as hothouse plants.
Like all the pitcher plants, the Nepenthes have a pitfall or passive trap, into which insects fall to drown in a soup of digestive juices. The pitcher is designed to ensure that the insect is attracted to a landing platform, the lid; it is then led on to the obviously ribbed rim and, once over this, to the inner waxy surface, where it tumbles into the waiting pool of liquid (to join not only other past meals but a host of animals, including mosquitoes and tree frogs, which use the pitchers as homes in the wild).
The traps hang on tendrils from the ends of beautiful, green, glossy leaves and are truly pitcher- or jug-shaped. They come in an enormous range of colours, shapes and sizes for, as well as a large number of species, there are innumerable hybrids, many of them created by the Victorians.
Pitcher production is at its peak in summer and occurs even on seedlings. Many plants have two types of pitcher, one at ground level and the other further up the vine-like stem, which enhances their appeal. Pitchers are from 2 to 14 in. (5-35 cm) long and the vines may grow to 50 ft (15 m), but do best if cut back annually.
Opposite: One of the many Nepenthes hybrids, with their spectacular pitchers and attractive leaves
The Victorian practice of growing Nepenthes in hothouses led to a belief that all need tropical temperatures. Fortunately, this is not true. Many are highland species, requiring cooler humid conditions to recreate their cloud forest habitat, and these will be happy if the nights are frost-free and the days cool or warm. Only the lowland species need tropical conditions, in other words, warm nights and hot days (see table 7).
Table 7: winter and summer temperatures suitable for lowland and highland Nepenthes
Day Night Day Night
Lowland species 70 ° F (21° C) minimum as high as possible
Highland species 64-71°F 52°F(11°C) 71-95°F as cool as (18-22°C) minimum (22-35°C) possible, but 52 °F (11°C) minimum
The traps of monkey cups are found in a wide variety of shapes and sizes
The traps of monkey cups are found in a wide variety of shapes and sizes
All Nepenthes dislike sunlight and, although their tolerances vary, most prefer about 50 per cent shading. Plastic sheets, netting or shading paint can be used. Netting has the advantage of being easily removed in winter, when less shading is required, and also does not inhibit ventilation too much. Pitcher development is in fact influenced by humidity rather than light. Too little light will affect only the colour of the pitcher and it is therefore better to overshade and then reduce the shading gradually, checking carefully for any sign of leaf or pitcher burn.
Regular misting or spraying three or four times a day is essential and the humidity can also be raised by damping down the greenhouse floor or placing plants above a large tray of water. An automatic misting device can be a worthwhile investment. Nepenthes will happily accept tap water, although in hard water areas the lime may form deposits that stain the leaves. Good drainage is vital and is easily provided by growing the plants in baskets. If this is not possible, they can be grown in pots of pure live sphagnum (in which case soft water rather than tap water must be used, in order not to kill the moss), with a live sphagnum wick to draw water up from a reservoir into the pot. Unlike most carnivorous plants, Nepenthes should be watered from above and must not stand in water, otherwise the roots will rot and the plants soon die. Compost: C or D. Temperature: see table 7.
Readily increased from stem cuttings and, as they become leggy with age and benefit from cutting back in spring, this should provide an ample supply of cuttings. They can also be raised from seed, which must be sown fresh on shredded sphagnum or pure perlite and kept at a temperature of 80°F (26°C). Mist regularly and do not allow the growing medium to dry out. Germination will occur in two to six weeks. Seedlings burn easily and should be well protected from direct sunlight.
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