bulb (redirected from vestibular bulb, vestibulovaginal bulb)

bulb, thickened, fleshy plant bud, usually formed under the surface of the soil, which carries the plant over from one blooming season to another. It may have many fleshy layers (as in the onion and hyacinth) or thin dry scales (as in some lilies)—both of which are highly modified leaves. Many popular outdoor and house plants, such as the tulip and the narcissus, are grown from bulbs, often out of their usual flowering season by forcing (i.e., by exposing them to a cold treatment). Not true bulbs, but often so called, are the corm of the crocus and the gladiolus, the tuber of the dahlia and the potato, and the rhizome of certain irises. All such organs are specialized subterranean stems serving for food and water storage and asexual reproduction.

Bibliography

See J. E. Bryan, Bulbs (1989).

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bulb

In botany, the resting stage of certain seed plants, particularly perennial monocotyledons (see cotyledon), consisting of a relatively large, usually globe-shaped, underground bud with membranous or fleshy overlapping leaves arising from a short stem. The fleshy leaves function as food reserves that enable a plant to lie dormant when water is unavailable (during winter or drought) and to resume active growth when favourable conditions again prevail. There are two main types of bulbs. One, typified by the onion, has a thin papery covering protecting its fleshy leaves. The other, the scaly bulb, as seen in true lilies, has naked storage leaves, with no papery covering, making the bulb appear to consist of angular scales. Bulbs enable many common ornamentals, such as the narcissus, tulip, and hyacinth, to flower rapidly in early spring when growing conditions are favourable. Other bulb-producing plants bloom in the summer (e.g., lilies) or fall (e.g., the autumn crocus). The solid corms of the crocus and gladiolus and the elongated rhizomes of some irises are not bulbs.

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bulb

1. a rounded organ of vegetative reproduction in plants such as the tulip and onion: a flattened stem bearing a central shoot surrounded by fleshy nutritive inner leaves and thin brown outer leaves

2. a plant, such as a hyacinth or daffodil, that grows from a bulb

3. See light bulb

4. a rounded part of an instrument such as a syringe or thermometer

5. Anatomy a rounded expansion of a cylindrical organ or part, such as the medulla oblongata

6. Nautical a bulbous protuberance at the forefoot of a ship to reduce turbulence

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bulb [bəlb]

(botany)

A short, subterranean stem with many overlapping fleshy leaf bases or scales, such as in the onion and tulip.

(electricity)

envelope