VOA慢速英语2010-SCIENCE IN THE NEWS - An Odyssey of Orchi

BARBARA KLEIN: This is SCIENCE IN THE NEWS in VOA Special English. I’m Barbara Klein.

STEVE EMBER: And I’m Steve Ember. Today we tell about the beauty and science of orchids², some of nature’s most interesting flowers.

Orchids at the U.S. Botanic Garden near the Capitol building in Washington

BARBARA KLEIN: Many people think of orchids as beautiful, sweet smelling, costly³ flowers that grow in hot tropical forests. But that is not the whole story of orchids. Some of the plants are found above the Arctic Circle. Some have an unpleasant smell. Not every species is lovely. And if you want to buy an orchid¹, it will cost a lot less than it once did.

Orchids are among the most common plant groups in the world. But some orchids that grow naturally are in danger of disappearing from Earth. At the same time, orchids produced in factories have become an important greenhouse crop.

Orchids come in many different shapes and colors

Orchid industry sales are especially important to places like the Netherlands, Singapore, Taiwan and Thailand. People enjoy orchids as decorative⁴ plants and cut flowers.

STEVE EMBER: Orchids come in all shapes, sizes, designs, colors and color combinations. The flowers may be tiny or large. But most have some common characteristics. The sepals of an orchid form the outside of the bud before the flower opens. There also are two regular petals⁶. The third petal⁵ is the lip. Orchids share this structure with lilies and irises⁷.

For reproduction, orchid flowers have male and female parts joined into one structure. The structure is called the column. The column is the most important quality that identifies the orchid family.

Not all orchids grow from the ground. Some are “air plants” that grow on trees. Unlike parasites⁸, however, they do not rob the trees of nutrition.

BARBARA KLEIN: Visitors are currently learning about orchids at the United States Botanic Garden in Washington, D.C. America’s plant museum and the Horticultural Services Division of the Smithsonian Institution are presenting the show “Orchids: A Cultural Odyssey⁹.”

Among the many visitors, Tonya Johnson came to the exhibit with young children from the Shabach Christian¹⁰ Academy in Landover, Maryland. She helped the children make discoveries about orchids.

STEVE EMBER: Live orchids form a rainbow of colors in the Botanic Garden’s conservatory¹¹ building. Orchid plants are blooming out of pots, climbing on trees or overflowing¹² from baskets among the garden’s permanent collection.

The world has an estimated twenty-five thousand kinds of orchids. A big blue globe near the opening of the exhibit shows places where orchids grow. The number of species in an area is written near its name.

For example, Costa Rica has one thousand five hundred species. The United States has seventy. The far northern nation of Greenland has four.

(MUSIC)

BARBARA KLEIN: Signs and overhanging banners help tell the stories of the plants on exhibit. Some of the orchids look like insects – butterflies, bees or spiders. Others look like stars, cups or lighted fireworks.

A colorful figure of a dragon with big teeth attracts attention to information about orchids in Sri Lanka. Orchids play an important part in special events in that country and on that country’s money. One banner shows the flowers on Sri Lanka’s one-hundred rupee note. Another banner shows delicate orchids on a five-dollar note from Singapore.

Orchids on display at the U.S. Botanical Garden

STEVE EMBER: Many visitors to the exhibit say they recognize some common orchid plants. The Cattleya, for example, gets a lot of attention.

The flower is sometimes called the corsage orchid. People wear the cut flower on clothing to celebrate special events like birthdays or Mother’s Day. There are many species of Cattleya. Most come from the treetops in wet tropical forests in Central and South America. They need warm temperatures to grow well.

BARBARA KLEIN: The Cattleya probably owes its existence to William Cattley, a British botanist¹³. In eighteen eighteen, Cattley saved the orchid plant from being thrown away. At the time, the plant was used as packing material that protected other orchid plants arriving from Brazil. Cattley succeeded in getting the unknown plant to flower. Later another botanist named it the Cattleya in his honor.

People often describe the deep color of the Cattleya lip as “showy.” But this part of the flower provides more than beautiful appearance. It serves as a landing area for bees and other insects that spread pollen¹⁴ to the plant. The colors and design of the lip help attract the insects.

STEVE EMBER: The nun’s orchid has an interesting name and shape. Not surprisingly, the flower looks like the head covering worn by some female Catholic religious workers. The nun’s orchid came first from China. It reached the United States in the eighteenth century. The flowers can be big, up to almost thirteen centimeters across. Some are brown with a lip that looks purple. Other possible color designs include yellows, reds and browns.

The vanilla¹⁵ orchid also has an interesting form. The fruit is inside the seedpods of its thick leaves. The leaves grow on tree trunks. Extract of vanilla provides a spice used in foods. The tiny dark dots in vanilla ice cream are from the seedpods of the vanilla orchid. The orchid grows in the rain forests of Mexico. It also grows in Madagascar, South America, Central America and warm areas of Asia and Africa.

(MUSIC)

BARBARA KLEIN: It is illegal to collect orchids growing in nature. But poachers often do so. And orchids reproduce with difficulty. They depend on birds, bees or insects to spread their pollen to another orchid flower.

Some orchids trick their pollinators. Such plants produce a smell that attracts pollinators not normally attracted to them. Other orchids trick male flies by making themselves look like female flies. Still others temporarily trap a pollinator. The action forces the insects to touch the orchid pollen. They pick it up on their bodies and carry it to another flower. Once the second flower is fertilized¹⁶, seeds begin to form.

Orchid seeds grow slowly. Sometimes they take months to develop inside the seedpods. The very small seedpods contain as many as three thousand seeds. The seeds float in the air when the pods break open. But they do not begin growing just anywhere.

STEVE EMBER: The seeds need to be near what is called a mycorrhizal fungus¹⁷. The seeds lack nutrients¹⁸, and the fungus feeds them. But the fungus is rare, and some of its habitats are threatened.

Thomas Mirenda is an orchid collection specialist at the Smithsonian Institution. Mister Mirenda says orchids growing in nature depend completely on their environment to survive.

Human development or natural disasters can change that environment. The orchids cannot reproduce if birds and insects are no longer living in the area. He says loss of forests and climate change are part of the problem.

Mister Mirenda also says very little money is available to help orchid conservation. He says financing is seriously endangered, like the orchids themselves.

(MUSIC)

BARBARA KLEIN: Today, science and technology can produce orchids in large numbers in greenhouse settings. In nineteen seventeen, Cornell University scientist Lewis Knudsen found that under certain conditions, the fungus was not needed. He discovered that seeds or spores¹⁹ could grow if the seed could develop in a special preparation. The preparation had a sugar base and was similar to gelatin, a food product. The method was put into use a few years later in greenhouses.

Seed germination²⁰ in sterile²¹ nutrients is now a common way to reproduce orchids.

STEVE EMBER: Mericloning also is a common modern method. The process calls for culturing from the merismatic tissue on a plant. Active growth takes place in that area. In the process, a small piece of tissue is taken from a high quality orchid. The tissue is made into tiny pieces and grown in a laboratory. Many exact copies of the orchid are produced. Whether grown naturally or through technology, people who love orchids say they are the most beautiful flowers on Earth.

(MUSIC)

BARBARA KLEIN: This program was written by Jerilyn Watson . Our producer was Brianna Blake. I’m Barbara Klein.

STEVE EMBER: And I’m Steve Ember. Go to our Web site, voaspecialenglish.com. You can comment on this story and other programs. You can share your thoughts and read what other people are saying. You can also find transcripts²², MP3s, podcasts and captioned²³ videos. Join us again next week for another program about science in Special English on the Voice of America.
 

1 orchid   

n.兰花，淡紫色

参考例句：

• The orchid is a class of plant which I have never tried to grow.兰花这类植物我从来没种过。
• There are over 35 000 species of orchid distributed throughout the world.有35,000多种兰花分布在世界各地。

2 orchids   

n.兰花( orchid的名词复数 )

参考例句：

• Wild flowers such as orchids and primroses are becoming rare. 兰花和报春花这类野花越来越稀少了。 来自《简明英汉词典》
• She breeds orchids in her greenhouse. 她在温室里培育兰花。 来自《简明英汉词典》

3 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

4 decorative   

adj.装饰的，可作装饰的

参考例句：

• This ware is suitable for decorative purpose but unsuitable for utility.这种器皿中看不中用。
• The style is ornate and highly decorative.这种风格很华丽，而且装饰效果很好。

5 petal   

n.花瓣

参考例句：

• Each white petal had a stripe of red.每一片白色的花瓣上都有一条红色的条纹。
• A petal fluttered to the ground.一片花瓣飘落到地上。

6 petals   

n.花瓣( petal的名词复数 )

参考例句：

• white petals tinged with blue 略带蓝色的白花瓣
• The petals of many flowers expand in the sunshine. 许多花瓣在阳光下开放。 来自《现代英汉综合大词典》

7 irises   

n.虹( iris的名词复数 )；虹膜；虹彩；鸢尾（花）

参考例句：

• The cottage gardens blaze with irises, lilies and peonies. 村舍花园万紫千红，鸢尾、百合花和牡丹竞相争艳。 来自《简明英汉词典》
• The irises were of flecked grey. 虹膜呈斑驳的灰色。 来自《简明英汉词典》

8 parasites   

寄生物( parasite的名词复数 )； 靠他人为生的人； 诸虫

参考例句：

• These symptoms may be referable to virus infection rather than parasites. 这些症状也许是由病毒感染引起的，而与寄生虫无关。
• Kangaroos harbor a vast range of parasites. 袋鼠身上有各种各样的寄生虫。

9 odyssey   

n.长途冒险旅行；一连串的冒险

参考例句：

• The march to Travnik was the final stretch of a 16-hour odyssey.去特拉夫尼克的这段路是长达16小时艰险旅行的最后一程。
• His odyssey of passion, friendship,love,and revenge was now finished.他的热情、友谊、爱情和复仇的漫长历程，到此结束了。

10 Christian   

adj.基督教徒的；n.基督教徒

参考例句：

• They always addressed each other by their Christian name.他们总是以教名互相称呼。
• His mother is a sincere Christian.他母亲是个虔诚的基督教徒。

11 conservatory   

n.温室，音乐学院；adj.保存性的，有保存力的

参考例句：

• At the conservatory,he learned how to score a musical composition.在音乐学校里，他学会了怎样谱曲。
• The modern conservatory is not an environment for nurturing plants.这个现代化温室的环境不适合培育植物。

12 overflowing   

n. 溢出物,溢流 adj. 充沛的，充满的 动词overflow的现在分词形式

参考例句：

• The stands were overflowing with farm and sideline products. 集市上农副产品非常丰富。
• The milk is overflowing. 牛奶溢出来了。

13 botanist   

n.植物学家

参考例句：

• The botanist introduced a new species of plant to the region.那位植物学家向该地区引入了一种新植物。
• I had never talked with a botanist before,and I found him fascinating.我从没有接触过植物学那一类的学者，我觉得他说话极有吸引力。

14 pollen   

n.[植]花粉

参考例句：

• Hummingbirds have discovered that nectar and pollen are very nutritious.蜂鸟发现花蜜和花粉是很有营养的。
• He developed an allergy to pollen.他对花粉过敏。

15 vanilla   

n.香子兰，香草

参考例句：

• He used to love milk flavoured with vanilla.他过去常爱喝带香草味的牛奶。
• I added a dollop of vanilla ice-cream to the pie.我在馅饼里加了一块香草冰激凌。

16 Fertilized   

v.施肥( fertilize的过去式和过去分词 )

参考例句：

• The study of psychology has recently been widely cross-fertilized by new discoveries in genetics. 心理学研究最近从遗传学的新发现中受益匪浅。
• Flowers are often fertilized by bees as they gather nectar. 花常在蜜蜂采蜜时受粉。

17 fungus   

n.真菌，真菌类植物

参考例句：

• Mushrooms are a type of fungus.蘑菇是一种真菌。
• This fungus can just be detected by the unaided eye.这种真菌只用肉眼就能检查出。

18 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

19 spores   

n.（细菌、苔藓、蕨类植物）孢子( spore的名词复数 )v.（细菌、苔藓、蕨类植物）孢子( spore的第三人称单数 )

参考例句：

• Ferns, mosses and fungi spread by means of spores. 蕨类植物、苔藓和真菌通过孢子传播蔓生。
• Spores form a lipid membrane during the process of reproducing. 孢于在生殖过程中形成类脂膜。 来自英汉非文学 - 生命科学 - 预防生物武器

20 germination   

n.萌芽，发生；萌发；生芽；催芽

参考例句：

• At the onset of germination, the hypocotyl elongates rapidly by cell enlargement. 萌发开始时，下胚轴依靠细胞增大而迅速伸长。 来自辞典例句
• Excessive moisture is unfavourable for soybean germination. 水分过多对于大豆萌发是不利的。 来自辞典例句

21 sterile   

adj.不毛的，不孕的，无菌的，枯燥的，贫瘠的

参考例句：

• This top fits over the bottle and keeps the teat sterile.这个盖子严实地盖在奶瓶上，保持奶嘴无菌。
• The farmers turned the sterile land into high fields.农民们把不毛之地变成了高产田。

22 transcripts   

n.抄本（ transcript的名词复数 ）；转写本；文字本；副本

参考例句：

• Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样，都是染色体DNA的转录产物。 来自辞典例句
• You can't take the transfer students'exam without your transcripts. 没有成绩证明书，你就不能参加转学考试。 来自辞典例句

23 captioned   

a.标题项下的； 标题所说的

参考例句：

• This paper reviews the production, development and nationalization of the captioned materials. 本文就铜系合金引线框架材料的生产、发展和国产化进程作一论述。
• Please advise other considerable hotels for this captioned group. 请推荐其它一些高级的旅馆给这一群打标语的人。