兰花能忍受长期干旱,这与它的根组织的生理生态有关。兰花的根没有主根、侧根之分,更没有吸收水分和养分的根毛,是一种吸收能力极强的单一肉质根条,根的外层是一层厚厚的海绵组织,伸缩力极大,到处都能快速地吸收水分和养分,具有根毛的作用。根的中央是一条拉力极强的梗心,是水分和养分的运输通道。笔者在一个经过秋旱连冬干的早春,在疏林中挖取的春兰,兰根干缩而布满皱折,像死根一样,而兰叶却浓绿而富有生气。携回后,将根系浸渍于清水中,不到半个钟头,便恢复了原有晶莹透亮的圆柱状肉质根。具有气生根的热带洋兰根系比国兰春兰更为奇特,它能和叶片一样裸露于空气中,摄取水分和制 Orchids can tolerate long-term drought, which is related to the physiology of its root tissue. Orchids root no root, lateral root points, but did not absorb moisture and nutrients in the root hair, is a strong absorption of a single fleshy roots, the root of the outer layer is a thick layer of sponge, great stretching force, Moisture and nutrients can be quickly absorbed everywhere, with the effect of root hairs. The root of the root is a very strong stretch of the heart, is the moisture and nutrients in the transport channel. The author in a dry autumn even after the early spring dry spring, digging in the sparse forest Chunlan, Langen dry shrinkage and wrinkled, like dead roots, while the leaves are dark green and full of life. After carrying back, the roots immersed in water, less than half an hour, it restored the original crystal clear translucent cylindrical fleshy roots. Roots of the tropical roots with tropical Lanna more unique than Cynanchum, it can be the same as leaves and exposed to the air, water intake and system