陕西省定边县第四中学高中英语 Unit 4 Exploring plants 背景材料 文章 Pitcher plants 素材 新人教版选修 9Tropical Pitcher plants are impressive plants, needing humidity and warmth. They can divided into two main groups - highland plants, and lowland plants, but there is some cross over where you find the intermediate ones. The produce two typed of trap - lower traps formed on lower growth, and upper pitchers formed when the plants get larger and start to climb. The lowland plants like temperatures of around 25oC all the time, with a slight drop in temperature at night. They are very intolerant of low temperatures (we have lost many to a power cut in the winter!) They also like humidity of 80% ideally. These things need to be quite constant, so monitoring is important. If you don't have suitable tropical greenhouse, a terrarium can be a good place to grow lowland plants, though they may well out grow it. All Nepenthes can be pruned of they get too big. Highland plants like a fluctuation in temperature, particularly between day and night. Ideally it should be 20oC during the day, and 15oC at night, but some will tolerate temperatures just above freezing at night. Humidity should be no less that 60%. Many highlands will grow well on a windowsill, the back o f a conservatory or in a shower room, but grow well in a warm greenhouse. Nepenthes like good light, but not the baking sun. They benefit from artificial lights in the winter as our days are so short. If grown in a greenhouse, 50% shade is needed. Watering Do not place in water trays. Water from the top and make sure they stay damp. Mist regularly -at least daily. This is very important, as humidity helps trap formation. If the tips of the leaves are drying before they produce traps, they need more humidity. Plants can be placed on gravel trays to increase humidity, or grown with other plants to help create a humid microclimate. If they have arrived through the post with empty traps, just put a little rainwater in each open trap. They will produce their own liquid normally. Feeding Nepenthes can be fed by putting insect or anything into the trap. Id does not have to be alive. They can also be fertilized with ½ strength orchid foliar feed about tw ice a month during the summer months. Just spray it on the leaves. Winter Care Lowland plants need constant conditions, winter and summer as far as possible. This can prove quite expensive in the winter. Many highlands will tolerate quite low temperatures in the winter, but they will sulk. Traps will die back over the winter start ing with the lid, then the whole trap and finally the leaf. Just remove dead parts.
