| 词汇 | bract |
| 释义 | bract noun[ C ] biology specializeduk /brækt/ us /brækt/ a type of leaf that grows from the area just below a flower and is sometimes different in shape or colour from the main leaves: 苞叶，苞片（长在花的底部，形状或颜色或不同于主叶） Poinsettias are popular for their attractive red bracts.一品红因其迷人的红色苞片广受喜爱。 espy3008/iStock/Getty Images Plus/Getty Images /GettyImages Parts of plants axil bark bilobed blade bulb caning cascara sagrada corolla endodermis inflorescence knot pistil rooty rosella seed coat seed pod sessile sting taproot tubule Examples of bractbract The vertical bract tips are about 2 mm long. Five whorls of bracts subtending sporangia are visible. The leaf-like bracts on this cone are almost indistinguishable from the normal vegetative leaves, except they are more curved towards the stem. When receptive, the stigmas release a species-specific fragrance, and the bracts in the neck of the inflorescence loosen, allowing the pollinators to enter. Seeds were germinated in their fruiting bracts or after bract removal. In each experimental patch, 10 plants had a red bract added, 10 plants had a green bract added and five plants had no bract. For each bract treatment values for the species are means of three temperatures. Due to the obliqueness of the section, bracts of the whorl above appear individualized. The number of bracts is unknown due to poor preservation. Individual growth was measured as the number of new leaves and floral bracts produced per individual. On female trees each inflorescence is solitary and consists of a single pedunculate flower surrounded by a whorl of bracts c. 7 mm long. On the male trees inflorescences are often in fascicles, and with each inflorescence a whorl of bracts surrounds a capitulum of apetalous male flowers. The bracts are red and flower colour is uniformly violet. The hibernacula are located in flower bracts, under lichens, loose bark and on other tree parts, which are relatively exposed to ambient weather conditions. In both seasons, seeds were germinated either in their fruiting bracts (fruits) or after handremoval of the fruiting bracts. These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors. |
| 随便看 |
反思网英语在线翻译词典收录了377474条英语词汇在线翻译词条，基本涵盖了全部常用英语词汇的中英文双语翻译及用法，是英语学习的有利工具。