Onion (plant part)

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Tulip bulbs , partly cut open
Hyacinth bulb sprouting a shoot
Blue onion from Lilium wallichianum
Tulip bulb with young next bulb

The onion , also called the globe , is a compressed shoot with thickened, often fleshy lower leaves , which serve as storage organs. Onions occur, for example, in the lily plants or many leek plants and are known as the "flower bulbs" of numerous garden plants.

construction

The bulbs usually grow underground to just above the soil surface. The onion shoot axis has greatly shortened internodes and forms a flat, disc-shaped part called the onion pie. On its surface there are flaky or tubular leaves, the lower leaf of which is thickened and swollen and stores nutrients (onion scales or onion skins). The upper leaves are usually green or later die off. The dry outer skin (onion cover or skin) protects the inner leaves from drying out. Unbranched sprout roots sprout from the underside of the onion pie and pull the onion into the ground as it grows. There the onion plant can survive an unfavorable season (winter or dry season) ( onion geophytes ). Inside the onion is the bud with the plant for foliage leaves leafless inflorescence stem and inflorescence for the next growing season .

An example of a shell onion is the kitchen onion . The bulbs of many lilies are developed as scaling onions .

Onions as reproductive organs

Daughter onions

In the leaf axils of the onion scales, one or two buds usually develop into small daughter onions. If the mother onion dies after flowering and fruiting of the plant, the daughter onions survive and are used for (vegetative) reproduction.

Brood onions

In some cases, bulbs also form in the axilla of leaves or in the inflorescence, for example in the fire lily or in the onion root . These bulbils (bulbils) are also reproductive organs.

Onions for food

Edible onions mainly belong to the leek family , such as the kitchen onion , shallot , winter onion , pearl onion and garlic . In addition, the above-ground onion of the vegetable fennel from the umbelliferae family and the onion of the edible prairie lily from the asparagus family are used as food.

Individual evidence

  1. ^ Peter Sitte, Hubert Ziegler, Friedrich Ehrendorfer, Andreas Bresinsky: Strasburger, textbook of botany. Gustav Fischer, Stuttgart, Jena, New York 1991, ISBN 3-437-20447-5 , p. 172.
  2. a b c d e Wolfgang Franke: Crop science, usable plants of the temperate latitudes, subtropics and tropics. 3rd edition, Thieme, Stuttgart, New York, NY 1985, ISBN 3-13-530403-5 , pp. 25-26, 199, 202, 366-368.
  3. ^ Peter Sitte, Hubert Ziegler, Friedrich Ehrendorfer, Andreas Bresinsky: Strasburger, textbook of botany. Gustav Fischer, Stuttgart, Jena, New York 1991, ISBN 3-437-20447-5 , p. 476.
  4. Native American Ethnobotany Database ( Memento of the original from January 20, 2009 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , University of Michigan @1@ 2Template: Webachiv / IABot / herb.umd.umich.edu

Web links

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