Biennial plant

A biennial plant is a flowering plant that takes two years to complete its lifecycle. In the first year the plant grows leaves, stems, and roots (vegetative structures), then it enters a period of dormancy over the colder months. Usually the stem remains very short and the leaves are low to the ground, forming a rosette. Many biennials require a cold treatment, or vernalization, before they will flower. During the next spring or summer, the stem of the biennial plant elongates greatly, or "bolts". The plant then flowers, producing fruits and seeds before it finally dies. There are far fewer biennials than either perennials or annuals.

Under extreme climatic conditions, a biennial plant may complete its life cycle in a very short period of time (e.g. three or four months instead of two years). This is quite common in vegetable or flower seedlings that were exposed to cold conditions, or vernalized, before they were planted in the ground. This behavior leads to many normally biennial plants being treated as annuals in some areas. Flowering can be induced in some biennials without vernalization by application of the plant hormone "gibberellin", but this is rarely done commercially.

. If a normally biennial plant is grown in extremely harsh conditions, it is likely to be treated as an annual because it will not survive the winter cold. Conversely, an annual grown under extremely favorable conditions may have highly successful seed propagation, giving it the appearance of being biennial or perennial. Some short-lived perennials may appear to be biennial rather than perennial. True biennials flower only once, while many perennials will flower every year once mature.

Examples of biennial plants are parsley, "Lunaria", silverbeet, Sweet William, colic weed, and carrot. Plant breeders have produced annual cultivars of several biennials that will flower the first year from seed, e.g. foxglove and stock.

ee also

*Annual plant
*Perennial plant

References


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Look at other dictionaries:

  • biennial plant — biennial plant. См. двулетник. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • biennial plant — dvimečiai augalai statusas T sritis ekologija ir aplinkotyra apibrėžtis Augalai, kurių vegetacinis periodas prasideda rudenį ir baigiasi kitą vasarą (pvz., morkos, kopūstai, runkeliai, svogūnai pirmaisiais metais kaupia šaknyse, lapuose arba… …   Ekologijos terminų aiškinamasis žodynas

  • Biennial — may refer to:* an event that occurs every two years * a biennial plant, a plant which blooms in its second year * a biennale, an art exhibition held every two years ee also* anniversary (for all other Latin derived numerical names) * , an event… …   Wikipedia

  • biennial — ► ADJECTIVE 1) taking place every other year. Compare with BIANNUAL(Cf. ↑biannually). 2) (of a plant) taking two years to grow from seed to fruition and die. ► NOUN 1) a biennial plant. 2) an event celebrated or taking place every two years …   English terms dictionary

  • biennial — (adj.) lasting for two years (1620s); occurring every two years (1750), from L. biennium two year period, from bi (see BI (Cf. bi )) + annus year (see ANNUAL (Cf. annual)). The vowel change is due to the Latin phonetic law according to which the… …   Etymology dictionary

  • biennial — biennially, adv. /buy en ee euhl/, adj. 1. happening every two years: biennial games. 2. lasting or enduring for two years: a biennial life cycle. 3. Bot. completing its normal term of life in two years, flowering and fruiting the second year, as …   Universalium

  • biennial — bi•en•ni•al [[t]baɪˈɛn i əl[/t]] adj. 1) happening every two years: biennial games[/ex] 2) lasting or enduring for two years 3) bot (of a plant) requiring two years to complete a life cycle; blooming and forming seeds in the second year 4) an… …   From formal English to slang

  • biennial — [bʌɪ ɛnɪəl] adjective 1》 taking place every other year. Compare with biannual. 2》 (of a plant) taking two years to grow from seed to fruition and die. Compare with annual, perennial. noun 1》 a biennial plant. 2》 an event celebrated or taking… …   English new terms dictionary

  • biennial — bi|en|ni|al [baıˈeniəl] adj [Date: 1600 1700; : Latin; Origin: biennium two year period , from bi ( BI ) + annus year ] 1.) a biennial event happens once every two years →↑annual 2.) a biennial plant stays alive for two years →↑annual, perennial… …   Dictionary of contemporary English

  • biennial — bi|en|ni|al [ baı eniəl ] adjective 1. ) a biennial event happens once every two years 2. ) a biennial plant lives for only two years ─ compare BIANNUAL …   Usage of the words and phrases in modern English

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