A weed of cultivation is any plant that is well-adapted to environments in which land is cultivated for growing some other plant. Many such

weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...

s are quite specialised and can only thrive and reproduce where the ground has been broken by plough or spade. They are invariably

annual Annual may refer to: *Annual publication, periodical publications appearing regularly once per year ** Yearbook ** Literary annual *Annual plant *Annual report *Annual giving *Annual, Morocco, a settlement in northeastern Morocco *Annuals (band), ...

and

reproduction Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual or ...

is by

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

alone, which can in many species lie dormant for years in the

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...

until brought to the surface during cultivation. They have fast reproduction cycles, usually in one year from seed to seed, though some species can have more than one generation in one season. A few species such as groundsel (''

Senecio vulgaris ''Senecio vulgaris'', often known by the common names groundsel and old-man-in-the-spring, is a flowering plant in the family Asteraceae. It is an annual herb, native to Europe and widely naturalised as a ruderal species in suitable disturbed ha ...

''), shepherd's purse (''

Capsella bursa-pastoris ''Capsella bursa-pastoris'', known as shepherd's purse because of its triangular flat fruits, which are purse-like, is a small annual and ruderal flowering plant in the mustard family (Brassicaceae). It is native to eastern Europe and Asia minor, ...

''), red deadnettle (''

Lamium purpureum ''Lamium purpureum'', known as red dead-nettle, purple dead-nettle, or purple archangel, is an annual herbaceous flowering plant native to Europe and Asia. Varieties: * ''Lamium purpureum'' var. ''hybridum'' (Vill.) Vill. (synonym: ''Lamium hybr ...

'') and chickweed ('' Stellaria media'') can survive unharmed through very cold weather and are often able to seed even in winter.

References

Weeds Agronomy Horticulture {{botany-stub

See also

References