英国学生科学读本 Lesson 74 蒲公英(2)

In spring, some hollow flower-stalks grow up from the centre of the rosette of leaves. Each stalk bears what looks like one large yellow flower. But if you pull one of these flower-heads to pieces, you will find that it is really made up of a great many small separate flowers, which all grow close together on the cushion-shaped top of the flower-stalk.

春天来临之际, 有些叶子的莲座丛中间会长出空心的花葶。每一根花葶头上都好像顶着一朵巨大的黄花。然而, 如果你将这样一个头状花序分解开来, 就会发现, 它其实由许多独立的小花构成, 它们全部生长在花茎的垫状顶部, 彼此紧密依靠在一起。

Outside the large flower-head is a double row of small green leaves, which protected the tiny flowers within when the "head" was only a bud. These small leaves look somewhat like the green cup or calyx which covers the young buds of single flowers. But they are really quite different.

巨大的头状花序外面长有两排小绿叶, 它们能够在“头状花序”只是蓓蕾时保护深藏其中的幼年小花。这些叶子看起来就像是绿色的杯子或者说是包裹着单生花的花蕾的花萼, 不过它们之间的区别很大。

If we pull off some of the many small yellow flowers or florets that make up the flower-head, and look at them very carefully, we shall see that each has an outside fringe of white hairs. These hairs are really the calyx or outer cup of the tiny flower; and although they do not seem to be of any use to it now, we shall see that they are of much use by-and-by. The little flower itself is a narrow tube, one side of which grows out into a long yellow ribbon.

取下几朵黄色的小花仔细观察, 就会发现, 每一只花朵外面都长有白色细丝状的边缘结构。这些才是真正的花萼;虽然现在它们看起来没什么作用, 不过我们逐渐就会了解到它们的重要功能。小花本身呈狭窄的管状结构, 其中一侧发育成为长长的黄色带状物。

Inside this tube are five very small dust-spikes, all growing together, and forming another and smaller tube. In the centre of the flower is the seed- vessel. At the bottom it is round and white like a little bag. From the top the slender yellow style rises, pushing two rough curving horns out beyond the flower-tube. These horns are ready to catch any pollen dust that insects may bring.

这个管状结构内部则是五个非常细小的雄蕊, 彼此紧靠在一起, 构成另外一个更小的管状结构。花朵中间则是种皮。底部是一个白色的袋装结构。顶部则长有细细的黄色花柱, 两个不平整的卷曲突起伸展而出, 扎根于花冠筒的上方。这两个突起随时准备捕捉昆虫传播过来的花粉。

英语美文