Delivery by bee蜜蜂送貨
Watch the bee arrive with pollen on its body, touch the stigma, and leave.
看蜜蜂帶著一身花粉飛來，碰到柱頭，再飛走。
Living Things · Unit 2 · Lesson 6 · 生命與生態 單元二 第六課
Why Do Flowers Bloom?花為什麼要開？
Flowers are not there to look pretty for us. They are how a plant makes seeds, and a plant cannot walk over to another plant. In a 3D model, cut a flower open and follow one grain of pollen: carried in by a bee, caught by the stigma, and then growing a tube down to a waiting seed-to-be. Switch to the wind and see why some plants must throw away so much pollen. Last, look at a flower and work out who delivers for it.
花不是為了讓我們覺得好看才開的。花是植物製造種子的方法，而植物沒辦法走到另一株植物那裡去。在 3D 模型裡把一朵花切開，跟著一粒花粉走：被蜜蜂帶進來、被柱頭接住，然後長出一條管子，通到等在那裡的「未來的種子」。換成風來送，看看為什麼有些植物非得浪費那麼多花粉不可。最後看著一朵花，推理出是誰在替它送貨。
Big idea · 一句話看懂
A flower is the part of a plant that makes seeds. To make a seed, pollen from one flower has to reach the stigma of another. A plant cannot move, so it uses a carrier. Many plants hire animals, and they pay with nectar and advertise with color and scent. Others let the wind do it and make huge amounts of pollen. When pollen arrives, it grows a tube down to an ovule. The ovule becomes a seed, and the part around it becomes a fruit.
花是植物用來製造種子的部分。要做出種子，一朵花的花粉必須送到另一朵花的柱頭上。植物不能移動，所以要找人送貨。很多植物雇用動物，用花蜜付工錢，用顏色和香味打廣告；另外一些讓風來送，於是得製造非常大量的花粉。花粉送到以後，會長出一條管子通到胚珠。胚珠變成種子，包著它的部分變成果實。
3D Model · 3D 模型
Follow the Pollen 跟著花粉走
Drag to turn the model, and scroll or pinch to zoom. The flower has been cut open so that you can see inside. Press Pause and move the slider slowly through the four steps. Watch where the pollen lands, and where the orange tube goes. Then choose By wind and run it again. What has changed about the flower, and how much of the pollen arrives?
拖曳可以旋轉模型，滾輪或雙指可以縮放。這朵花被切開了，讓你看得到裡面。按「暫停」，慢慢拉動滑桿，走過四個階段。注意花粉落在哪裡、橘色的管子通到哪裡。接著選「風送」再跑一次：這朵花有什麼地方不一樣了？花粉又有多少送得到？
Drag to turn · 拖曳旋轉 Scroll or pinch to zoom · 滾輪／雙指縮放
This 3D model needs WebGL, which this browser does not support. The reading and the cards below still explain everything.
這個瀏覽器不支援 WebGL，無法顯示 3D 模型；下方的課文與卡片一樣能看懂。
- Pink: petals, the signboard
粉紅色：花瓣，招牌 - Yellow: anthers and pollen
黃色：花藥和花粉 - Green: the stigma, the style below it, and the ovary
綠色：柱頭、下面的花柱，還有子房 - Orange line: the pollen tube
橘色的線：花粉管 - Orange: the ovary swelling into a fruit
橘色：子房膨大成果實
A teaching model. The parts are not to scale: pollen grains are far too small to see like this. The numbers of grains are examples. Real flowers come in thousands of shapes, and many have their parts in different numbers and places. A real wind-pollinated flower usually looks quite different from the other kind, and the model changes only a few things so that you can compare them. The steps shown take hours or days.
這是教學用的模型。各部分沒有照比例：花粉粒其實小到不可能這樣看見。花粉的粒數是示意。真的花有成千上萬種形狀，很多花各部分的數目和位置都不一樣。真正靠風傳粉的花，樣子通常和另一類差很多；模型只改了幾個地方，方便你比較。畫面裡的過程，實際上要花幾小時到幾天。
Model drawn by My Culture Connect as a teaching diagram. The ideas follow the sources listed at the bottom of this page. · 模型由人師教育協會自繪示意；原理依本頁最下方列出的出處。
Reading · 英文閱讀
6
Unit 6: Why Do Flowers Bloom?
A plant has a problem that an animal does not have. To make seeds, it usually needs something from another plant of its own kind. But it is rooted to the ground and cannot go and get it. A flower is the answer to that problem.
植物有一個動物沒有的難題。要做出種子，它通常需要另一株同類植物身上的東西；可是它的根扎在地上，沒辦法自己過去拿。花，就是用來解決這個難題的。
Look into the middle of a flower. Around the center there is a ring of thin stalks, each with a small bag on top. The bags are called anthers, and they make pollen, a fine yellow dust. Right in the center stands the stigma. It is often sticky, and below it, at the bottom of the flower, are the ovules. Each ovule can become a seed.
往一朵花的中間看。圍著中心有一圈細細的柄，每一根的頂端有一個小袋子。這些小袋子叫做花藥，會製造花粉——一種細細的黃色粉末。正中央立著的是柱頭，通常黏黏的；在它的下方、花的最底部，是胚珠。每一顆胚珠都可能變成一粒種子。
A seed begins when pollen from one flower lands on the stigma of another. Something has to carry it there. About four out of five kinds of flowering plants use animals: bees, butterflies, moths, flies, beetles, birds, and bats. The animal comes for nectar, a sugary drink, and carries pollen away on its body without meaning to.
一朵花的花粉落到另一朵花的柱頭上，種子才會開始形成。花粉得有人送過去。每五種開花植物裡，大約有四種靠動物：蜜蜂、蝴蝶、蛾、蠅、甲蟲、鳥，還有蝙蝠。動物是為了花蜜（一種含糖的飲料）而來，花粉沾在身上，就這樣在不知不覺中被帶走了。
This is why so many flowers are bright and sweet-smelling. The color and the scent are advertising, and the nectar is the pay. Some flowers even have lines on their petals that point the way to the nectar.
所以才有這麼多花又鮮豔又香。顏色和香味是廣告，花蜜是工錢。有些花的花瓣上甚至有線條，指出花蜜在哪裡。
Other plants use the wind. Grasses and oak trees are like this. Their flowers are small and dull, with no scent, because the wind does not need to be invited. But the wind does not aim, so these plants make enormous amounts of light pollen, and they catch it with stigmas shaped like feathers.
另外一些植物靠風。禾草和橡樹就是這樣。它們的花又小又不起眼，也沒有香味，因為風用不著邀請。可是風不會瞄準，所以這些植物會製造非常大量、非常輕的花粉，再用羽毛形狀的柱頭去接。
When a grain of pollen lands on the right stigma, it grows a thin tube down to an ovule. Then the ovule becomes a seed, and the part of the flower around it, the ovary, grows into a fruit. A tomato, a peach, and a bean pod were all once the middle of a flower.
一粒花粉落在對的柱頭上以後，會長出一條細細的管子，通到一顆胚珠。接著胚珠變成種子，而花朵裡包著它的那個部分——子房——長成果實。番茄、桃子和豆莢，原本都是一朵花的中心。
Read aloud · 課文朗讀
Questions · 閱讀理解
What problem does a flower solve for a plant?
A plant cannot move, so it cannot go to another plant to get pollen. A flower lets something else carry the pollen.
Why are many flowers bright and sweet-smelling?
The color and the scent are advertising for animals, and the nectar is their pay for carrying pollen.
What does the ovary of a flower become?
It becomes a fruit, with the seeds inside it.
Words & Phrases · 生字及片語
flower(n.)花A flower is where a plant makes its seeds.花是植物製造種子的地方。petal(n.)花瓣This rose has soft red petals.這朵玫瑰有柔軟的紅色花瓣。pollen(n.)花粉The bee is covered in yellow pollen.這隻蜜蜂全身都是黃色的花粉。nectar(n.)花蜜Butterflies drink nectar from flowers.蝴蝶從花裡吸花蜜。bee(n.)蜜蜂A bee flew from flower to flower.一隻蜜蜂從一朵花飛到另一朵花。scent(n.)香味；氣味The scent of the flowers filled the garden.花園裡滿是花的香味。fruit(n.)果實；水果The flower became a small green fruit.那朵花變成了一顆小小的綠色果實。bloom(v. / n.)開花The cherry trees bloom in spring.櫻花樹在春天開花。
Quick Check · 小測驗
1. What is a flower for?
2. Which part of a flower makes pollen?
3. Why do bees visit flowers?
4. What is true of flowers that use the wind?
5. What does an ovule become after pollen reaches it?
Be the Botanist · 當一次植物學家
Who delivers the pollen? 誰來送花粉？
You can often tell who carries a flower's pollen just by looking at it. Tick what the flower has, and see what that suggests.
只要看一朵花的樣子，常常就猜得出是誰替它送花粉。把這朵花有的特徵打勾，看看這代表什麼。
What is the flower like? · 這朵花長什麼樣子？
This is a rule of thumb, and flowers are full of exceptions. It works best as a first guess, which you then check by watching the flower.這只是一個粗略的判斷方法，花的世界到處都是例外。最好把它當成第一個猜測，再去觀察那朵花來驗證。
Its pollen is probably carried by · 它的花粉大概是靠
Try It in the Model · 在模型裡試試
Four things to watch 四件值得看的事
In both versions, steps 3 and 4 are exactly the same. Only the delivery is different. One plant pays for a careful carrier, and the other pays nothing and sends far more.
兩種版本的第三、第四階段完全一樣，不一樣的只有送貨的方式：一種植物付錢請仔細的送貨員，另一種一毛錢也不付，但是送出去的多得多。
Delivery by wind風送貨
Forty grains blow past. Count how many of them touch the stigma.
四十粒花粉飄過去。數數看有幾粒碰到柱頭。
The pollen tube花粉管
Follow the orange line down from the stigma. Where is it heading?
順著橘色的線從柱頭往下看。它要去哪裡？
From flower to fruit從花到果實
The petals are gone and the ovary has swollen. Find the one ovule that became a seed.
花瓣掉了，子房脹大了。找出變成種子的那一顆胚珠。
Go Further · 延伸閱讀
What comes before, and what comes next 之前的事，和接下來的事
Living Things · Lesson 5 · 生命與生態 第五課How Does a Seed Know When to Grow?種子怎麼知道什麼時候該發芽？See what happens to the seed that the flower made.看看花做出來的那粒種子，後來怎麼樣了。Go to the lesson · 前往這一課 →Living Things · Lesson 3 · 生命與生態 第三課What Is DNA?DNA 是什麼？Pollen carries half of the instructions for the new plant.花粉帶著新植物一半的說明書。Go to the lesson · 前往這一課 →
Flowers by the Numbers · 花的數字
Six numbers about flowers 六個和花有關的數字
Who carries the pollen, and how far it has to go.
誰在送花粉，花粉又要走多遠。
80%of flowering plants · 的開花植物
About this share rely on living carriers, mostly insects, to move their pollen.大約這麼高的比例，是靠生物（大多是昆蟲）來搬運花粉的。
4rings · 圈
A typical flower is built in four rings: sepals, petals, stamens, and the pistil in the middle.典型的花由四圈構成：萼片、花瓣、雄蕊，還有正中央的雌蕊。
30 cmand more · 以上
In corn, a single pollen tube can grow longer than this to reach its ovule.玉米的一條花粉管可以長得比這還長，才到得了胚珠。
1793the year · 年
Christian Konrad Sprengel published the idea that flowers exist to attract insects.施普倫格爾發表了他的看法：花的存在是為了吸引昆蟲。
0paid · 報酬
Wind-pollinated flowers make little or no nectar and no scent. The wind works for free.靠風傳粉的花幾乎不製造花蜜，也沒有香味。風是免費的。
1ovary · 個子房
A fruit is the ovary of a flower, grown large after the flower has finished.果實就是花的子房，在花謝了以後長大而成。
Flower Stories · 花的故事
A teacher nobody believed, hidden lines, the food on your plate, and lights in the fields of Tianwei 沒有人相信的老師、看不見的線條、你盤子裡的食物，還有田尾田裡的燈
What people have learned by watching flowers closely.
人們仔細觀察花朵之後學到的事。
1793
The secret of nature大自然的祕密
Christian Konrad Sprengel was a German teacher who spent years watching insects visit flowers. In 1793 he published a book explaining that the purpose of a flower is to attract insects, and that nature favors pollen brought from another plant. Few people took notice. His work was not widely recognized until Charles Darwin tested and confirmed his observations many years later.
施普倫格爾是一位德國教師，花了好多年觀察昆蟲造訪花朵。1793 年他出版了一本書，說明花的功用是吸引昆蟲，而且大自然偏好從別株帶來的花粉。當時沒有什麼人注意。直到很多年以後，達爾文檢驗並證實了他的觀察，他的研究才被廣泛認可。
Ultraviolet · 紫外光
Lines we cannot see我們看不見的線條
Some flowers have marks on their petals that guide a visitor to the nectar, like lines painted on a runway. In some plants, such as the meadow buttercup, the marks show up only in ultraviolet light, which human eyes cannot see. To us the flower is plain yellow. Seen in ultraviolet, it has a dark center where the nectar is.
有些花的花瓣上有記號，把訪客引到花蜜那裡，就像畫在跑道上的線。有些植物（例如草地毛茛）的記號只有在紫外光下才看得出來，而人的眼睛看不見紫外光。在我們眼裡，那朵花是一片單純的黃色；在紫外光下，它的中心是深色的，花蜜就在那裡。
Kitchen · 廚房
Fruits in disguise偽裝的果實
To a cook, a fruit is something sweet. To a botanist, a fruit is whatever grows from the ovary of a flower and holds the seeds. By that meaning, bean pods and nuts are fruits as well. Next time you cut one open, look for the seeds, and remember that each one began with a grain of pollen.
對廚師來說，水果是甜的東西。對植物學家來說，凡是由花的子房長成、裡面裝著種子的，都是果實。照這個意思，豆莢和堅果也是果實。下次切開它們的時候，找找裡面的種子，並且記得：每一粒種子，最初都是從一粒花粉開始的。
Taiwan · 台灣
Why the fields of Tianwei are lit at night田尾的田為什麼晚上點燈
Chrysanthemums bloom in autumn, when the nights grow long. The plant measures the length of the night, and a long night is its signal to make flower buds. Growers in Tianwei, Changhua, hang lamps over their fields and switch them on after dark. The night is made short, so the plants keep growing and do not bloom. When the growers want flowers, they turn off the lamps. That is how flowers can be ready for the right day, on long stems.
菊花在秋天開花，那時候夜晚變長了。菊花會測量夜晚的長度，夜一長，就是它長出花苞的信號。彰化田尾的花農在田裡吊起燈泡，天黑之後點亮，把長夜變成短夜，菊花就繼續長高而不開花。等到想要花的時候，再把燈關掉。這樣花就能在需要的日子開，而且花莖夠長。
Myth vs. Fact · 常見迷思
Four things people get wrong 四個常見的誤會
✗ Myth · 迷思Flowers are there to look pretty.花是為了好看才開的。
✓ Fact · 事實Flowers are there to make seeds. The color is advertising for the animals that carry pollen.花是為了製造種子。顏色是給搬運花粉的動物看的廣告。
✗ Myth · 迷思Bees visit flowers to help the plant.蜜蜂去採花是為了幫植物的忙。
✓ Fact · 事實Bees come for nectar and pollen to eat. Carrying pollen between flowers is a side effect.蜜蜂是為了吃花蜜和花粉而來。在花與花之間搬運花粉，只是順帶發生的事。
✗ Myth · 迷思Grass and trees like oaks have no flowers.草和橡樹這類的樹不會開花。
✓ Fact · 事實They do. Their flowers are small and plain because the wind carries their pollen.它們會開花，只是花又小又樸素，因為它們的花粉是風送的。
✗ Myth · 迷思Fruits and flowers are separate things.果實和花是兩回事。
✓ Fact · 事實A fruit grows from the ovary of a flower. Every fruit was once part of a flower.果實是由花的子房長成的。每一顆果實，都曾經是花的一部分。
Remember It · 記憶口訣
A flower in a sentence 一句話記住花
A flower makes seeds花是做種子的
That is its whole job.
這就是它全部的工作。
Pollen must travel花粉要出門
From an anther to another flower's stigma.
從花藥到另一朵花的柱頭。
Pay an animal, or use the wind付錢給動物，或是靠風
Nectar and color, or clouds of pollen.
花蜜和顏色，或是一大片花粉。
Ovule to seed, ovary to fruit胚珠變種子，子房變果實
After a pollen tube arrives.
在花粉管抵達之後。
An Observer's Code · 觀察守則
Watching flowers without harming them 看花，但不傷害它們
- Pick only flowers that you have permission to pick, and never pick wild flowers in a park or a nature reserve.只摘得到允許的花；公園和保護區裡的野花不要摘。
- Watch bees and wasps from an arm's length away, and do not wave at them or try to touch them.觀察蜜蜂和胡蜂時，保持一隻手臂的距離，不要揮趕，也不要去碰。
- Leave every insect where you found it.每一隻昆蟲都留在原來的地方。
Classroom Activity 1 · 課堂活動一
Take a Flower Apart 把一朵花拆開
You need · 準備材料
- One large flower that you are allowed to pick, such as a lily or a hibiscus一朵得到允許可以摘的大花，例如百合或朱槿
- A sheet of white paper, tape, and a magnifying glass一張白紙、膠帶和一支放大鏡
Steps · 步驟
- Starting from the outside, gently pull off each ring of parts and tape it to the paper in a row.從最外面開始，輕輕把每一圈的構造摘下來，在紙上貼成一排。
- Label each row: sepals, petals, stamens, and the pistil in the middle.替每一排寫上名稱：萼片、花瓣、雄蕊，還有正中央的雌蕊。
- Touch an anther to the paper. Look at the dust it leaves through the magnifying glass.拿一個花藥在紙上輕輕碰一下，用放大鏡看它留下的粉末。
- Ask an adult to cut the bottom of the pistil across. Can you see the ovules inside?請大人把雌蕊的底部橫切開來。你看得到裡面的胚珠嗎？
Lily pollen stains cloth, so cover the table. Count the parts in each ring. In many flowers the numbers are related, such as three and six, or five and ten.
百合的花粉會把布染色，桌面先鋪一層紙。數一數每一圈有幾個；很多花各圈的數目是有關係的，例如三和六，或是五和十。
Classroom Activity 2 · 課堂活動二
Ten Minutes at a Flower 在一朵花旁邊待十分鐘
You need · 準備材料
- A notebook and a pencil一本筆記本和一支鉛筆
- A patch of flowers outdoors on a warm, dry day晴朗溫暖的日子裡，戶外的一小片花
Steps · 步驟
- Choose one flower, or one small group of flowers, and sit where you can see it clearly.選一朵花，或一小叢花，坐在看得清楚的地方。
- For ten minutes, make a mark for every visitor: bee, butterfly, fly, beetle, or something else.在十分鐘裡，每來一位訪客就畫一個記號：蜜蜂、蝴蝶、蠅、甲蟲，或是別的。
- For each visitor, notice where it lands and which parts of the flower it touches.留意每一位訪客降落在哪裡、碰到了花的哪些部分。
- Do the same at a different kind of flower. Are the visitors the same?換一種花再做一次。來的訪客一樣嗎？
Try it at different times of day. Some flowers open only in the morning, and some are visited mostly at dusk.
在一天裡不同的時間試試看。有些花只在早上開，有些花的訪客大多在黃昏才來。
Sources · 資料出處
Facts and numbers on this page were checked against these sources (October 2026). · 本頁的事實與數字依下列資料查證（2026 年 10 月）。
- Flowers are the reproductive structures of flowering plants, typically built in four rings: sepals, petals, stamens, and the pistil; the stamens present the pollen and the stigma receives it and directs it to the ovules in the ovary; nectar guides may be visible only under ultraviolet light; after pollination and fertilization the resulting cell grows into a seed花是開花植物的生殖構造，典型由四輪構成：萼片、花瓣、雄蕊、雌蕊；雄蕊提供花粉，柱頭接收花粉並導向子房內的胚珠；蜜源標記可能只在紫外光下可見；授粉與受精之後發育成種子Wikipedia, “Flower” ↗
- About 80% of flowering plants rely on biotic pollination; abiotic pollination relies on wind or water; cross-pollination is the delivery of pollen from the stamen of one flower to the stigma of a flower on another plant of the same species約 80% 的被子植物仰賴生物傳粉；非生物傳粉靠風或水；異花授粉是花粉由一朵花的雄蕊送到同種另一株植物的花的柱頭Wikipedia, “Pollination” ↗
- Pollinators include bees, wasps, flies, butterflies, moths, and beetles, and among vertebrates mainly bats and birds傳粉者包括蜂類、蠅類、蝴蝶、蛾、甲蟲；脊椎動物主要是蝙蝠和鳥類Wikipedia, “Pollinator” ↗
- Nectar is a sugar-rich liquid produced by plants, with which flowers attract pollinating animals花蜜是植物分泌的含糖液體，花朵用它吸引傳粉的動物Wikipedia, “Nectar” ↗
- Nectar guides are markings that guide pollinators to their rewards; in some plants, such as the meadow buttercup, they are visible only in ultraviolet light, where the flowers have a darker center蜜源標記是引導傳粉者找到報酬的花紋；有些植物（如草地毛茛）的標記只在紫外光下可見，花心顏色較深Wikipedia, “Nectar guide” ↗
- Wind-pollinated flowers lack scent and showy parts, make little nectar, and produce enormous numbers of light, smooth pollen grains; they have large, feathery stigmas; grasses and oaks are wind-pollinated風媒花沒有香味、沒有顯眼的構造、花蜜少，製造極大量又輕又光滑的花粉，柱頭大而呈羽毛狀；禾草與橡樹是風媒植物Wikipedia, “Anemophily” ↗
- The pollen tube carries the male cells from the pollen grain on the stigma to the ovules; in maize a single tube can grow longer than 12 inches (30 cm)花粉管把雄性細胞從柱頭上的花粉粒送到胚珠；玉米的單一花粉管可以長到超過 30 公分Wikipedia, “Pollen tube” ↗
- In botany a fruit is the seed-bearing structure formed from the ovary after flowering; the term includes nuts and bean pods植物學上，果實是開花後由子房形成、內含種子的構造；堅果與豆莢也算果實Wikipedia, “Fruit” ↗
- Sprengel's book of 1793; he was the first to recognize that the function of flowers was to attract insects and that nature favored cross-pollination; his work was not widely recognized until Charles Darwin confirmed several of his observations施普倫格爾 1793 年的著作；他最早認識到花的功能是吸引昆蟲、自然界偏好異花授粉；直到達爾文證實他的多項觀察後才受到廣泛認可Wikipedia, “Christian Konrad Sprengel” ↗
- The chrysanthemum is a short-day plant, in fact a long-night plant, which forms flower buds when the nights grow long; lamps lit at night turn the long night into a short one and hold back flowering, to adjust the harvest date and to lengthen the stems菊花是短日植物（其實是「長夜植物」），夜變長時才花芽分化；夜間點燈把長夜變成短夜，抑制開花，用來調節產期並延長花莖農業部 農業知識入口網 菊花主題館〈菊花為什麼要電照？〉（許謙信撰） Ministry of Agriculture, Taiwan ↗
- The sea of lights over the chrysanthemum fields is a feature of Tianwei「電照菊花的燈海」是田尾的一大特色彰化縣田尾鄉公所〈電照菊花栽培〉 Tianwei Township Office, Changhua County ↗