Editing Bulb (section)

==Description==
[[File:Red onion cut labelled.svg|thumb|Longitudinal section through bulb]]
[[File:Red onion cross section 04.jpg|thumb|Cross section of onion bulb]]
The bulb's leaf bases, also known as [[Cataphyll|scales]], generally do not support leaves, but contain food reserves to enable the plant to survive adverse conditions. At the center of the bulb is a vegetative growing point or an unexpanded flowering shoot. The base is formed by a reduced [[Plant stem|stem]], and plant growth occurs from this basal plate. [[Root]]s emerge from the underside of the base, and new stems and leaves from the upper side. '''Tunicate''' bulbs have dry, membranous outer scales that protect the continuous lamina of fleshy scales.<ref name="Mishra">{{cite book |url=https://books.google.com/books?id=giqdNdoJNQsC |first=S.R. |last=Mishra |title=Plant Reproduction |publisher=Discovery Publishing House |year=2005 |isbn=978-81-7141-955-5 |pages=120–125}}</ref> Species in the genera ''[[Allium]]'', ''[[Hippeastrum]]'', ''[[Narcissus (plant)|Narcissus]]'', and ''[[Tulip]]a'' all have tunicate bulbs. Non-tunicate bulbs, such as ''[[Lilium]]'' and ''[[Fritillaria]]'' species, lack the protective tunic and have looser scales.<ref name="Ellis">{{cite book |url=https://archive.org/details/taylorsguidetobu00elli |url-access=registration |first=Barbara W. |last=Ellis |title=Bulbs |publisher=[[Houghton Mifflin Harcourt]] |year=2001 |isbn=978-0-618-06890-6 |page=[https://archive.org/details/taylorsguidetobu00elli/page/3 3]}}</ref>

Bulbous plant species cycle through vegetative and reproductive growth stages; the bulb grows to flowering size during the vegetative stage and the plant flowers during the reproductive stage. Certain environmental conditions are needed to trigger the transition from one stage to the next, such as the shift from a cold winter to spring.<ref name="Mishra"/> Once the flowering period is over, the plant enters a foliage period of about six weeks during which time the plant absorbs nutrients from the soil and energy from the sun for setting flowers for the next year. Vegetative bulbs may be planted like seeds and will sprout into plants. Bulbs dug up before the foliage period is completed will not bloom the following year but then should flower normally in subsequent years.<ref name=":0">{{Cite journal |title=Advances in bulb crops |url=https://www.primescholarslibrary.org/articles/advances-in-bulb-crops.pdf |journal=Department of Agriculture, Andhra University, Visakhapatnam, Andhra Pradesh, India.}}</ref>