Although axillary buds produce flowers, they always produce a bit of stem tissue first: the very first appendage primordia are leaf primordia, not sepal primordia. In most cacti, the axillary bud apical meristem actually produces 20 or 30 or more leaf primordia before it actually switches over to producing floral appendage primordia. The noteworthy thing is that these leaf primordia typically develop much more than do other leaf primordia on the same plant, and they mature into large scales that may be a centimeter or more long and have a thin, flat lamina-like region. People typically do not realize that these cactus leaves are true leaves but they are indeed. They are usually called “scales” or “bracts” but that does not matter: they are leaves. The problem is that the ovary is so deeply inferior that these leaves appear to be part of a flower rather than part of a vegetative stem.
頂端 
加到"我的最愛"
主題管理：
總固頂 
取消總固頂 
Message
查看
搜尋
通訊錄
複製
引用
回覆
2010/07/19 05:41pm 
IP: 已設定保密
...現在得跟英文真槍實彈火拼了 
我電子字典不離手，還要加上五色原子筆才能搞定這些東西。