这是个倒装句型,我们把它拆开来看,xxxx代表an unmistakable landing strip to attract the specific insect,先抛开它不看.句子原语序是这样：
The orchid has chosen as its pollinator (a way/method/thing) dramatically marked as xxxx.
对上面这个句子进行倒装,就是It is (a way/method/thing) dramatically marked as xxxx the orchid has chosen as its pollinator.再省略掉括号里的成分就变成了你的句子.
整句话意思是“兰花选择作为其授粉器官的东西被戏剧性地当成了xxxx”.
然后我们再看xxxx,也就是“an unmistakable landing strip to attract the specific insect”,这个短语的结构应该是很好理解的,意思就是“一个以吸引那种昆虫为目标的准确无误的起飞跑道”.landing strip原意是飞机场的起飞道,这里算是一种比喻吧.
最开始我是把它当强调句理解的,后来发现不对,应该是倒装更合适些.这不是一个非常标准的句子.希望我的解释你可以明白.如果你还有哪儿想不通,发消息问吧.