perennial

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perennial,

any plant that under natural conditions lives for several to many growing seasons, as contrasted to an annualannual,
plant that germinates from seed, blossoms, produces seed, and dies within one year. Annuals propagate themselves by seed only, unlike many biennials and perennials. They are thus especially suited to environments that have a short growing season.
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 or a biennialbiennial,
plant requiring two years to complete its life cycle, as distinguished from an annual or a perennial. In the first year a biennial usually produces a rosette of leaves (e.g., the cabbage) and a fleshy root, which acts as a food reserve over the winter.
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. Botanically, the term perennial applies to both woody and herbaceous plants (see stemstem,
supporting structure of a plant, serving also to conduct and to store food materials. The stems of herbaceous and of woody plants differ: those of herbaceous plants are usually green and pliant and are covered by a thin epidermis instead of by the bark of woody plants.
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) and thus includes numerous members of the kingdom. In horticulture, however, the term is usually restricted to hardy herbaceous perennials, particularly border plants such as alyssum, chrysanthemum, iris, peony, phlox, pink, and sedum, all of which characteristically die down to the ground each year and survive the winter on food stored in specialized underground stems (corms, rhizomes, and tubers in horticulture; bulbous plants are not considered perennials). Perennials form seeds each year after reaching maturity, but since plants grown from seeds do not normally bloom until the second season (unless forced), most garden perennials are propagated by dividing the rootstocks (see propagation of plantspropagation of plants
is effected in nature chiefly sexually by the seed and the spore, less often by rhizomes and other methods (see reproduction). Vegetative means include cutting, layering, grafting, tissue culture, and division of the roots (see perennial) and of the tubers
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). In fact, division every few years—as well as judicious pruning—is usually necessary to prevent the plant's becoming straggly and weak. Perennials, including the woody perennials, may have a rest period of some duration during their life cycle. In the plant different parts rest at different times and resume growth independently, e.g., the buds of deciduous plants, which form in late summer and remain dormant until spring. Even in tropical areas where plants appear to retain their leaves the year round, some plants lose all their leaves for a brief period and others grow new and drop old leaves on a continuing basis, as do most conifers.

Bibliography

See R. W. Cumming and R. E. Lee, Contemporary Perennials (1960); J. U. Crockett, Perennials (1972); A. M. Armitage, Herbaceous Perennial Plants (1989); R. R. Clausen and N. H. Ekstrom, Perennials for American Gardens (1989); P. J. Harper, Designing with Perennials (991).

perennial

[pə′ren·ē·əl]
(botany)
A plant that lives for an indefinite period, dying back seasonally and producing new growth from a perennating part.

perennial

A plant or shrub whose life cycle is greater than 2 years.

perennial

a woody or herbaceous plant that can continue its growth for at least two years
References in periodicals archive ?
The moderate to high estimates of narrow-sense heritability in this study suggested that improving gray leaf spot resistance in perennial ryegrass would be very effective through a genotypic recurrent selection breeding program.
Populations were similar under grazed and mown (data not shown) perennial ryegrass, and were similar under ryegrass-white clover and herb ley (data not shown).
A fructosyltransferase (LpFT1) cDNA and its promoter region was isolated from perennial ryegrass (Chalmers et al., 2003).
Fungicide effects on Acremonium endophyte, plant parasitic nematodes, and thatch in Kentucky bluegrass and perennial ryegrass. Plant Dis.
How perennial ryegrass from our fields and back gardens could be turned into fuel for our cars
Significant (P < 0.05) GL interaction variance for turf density was found only in red rescue and perennial ryegrass. However, the modest size of the [s.sup.2.sub.L(rg)] relative to the [s.sup.2.sub.g] and the relatively high pooled genetic correlation among locations ([r.sub.g] > 0.80) indicated that crossover GL effects were also fairly small in these species (Table 2).
(1996), who reported that white clover (Trifolium repens L.) patch size increased and harvested mass was greater in cut perennial ryegrass (Lolium perenne L.)-white clover swards, while patch size remained unchanged in grazed swards.
If there's too much annual meadowgrass and other wild grasses, and too few sown species like perennial ryegrass, it is time for action.
IBERS is looking to use perennial ryegrass for production of ethanol as a transport fuel - not only is it a potential new source of income for farmers, it won't use crops normally grown for human food.
This short-to-medium-term cutting and grazing mixture contains AberRuby - the first of the new generation of red clovers - and the high-sugar perennial ryegrass AberDart and high-sugar hybrid AberEcho.
Five chapters cover topics that include toxicosis of sheep caused by specific toxins produced in endophyte-infected perennial ryegrass, the use of animal models in studying toxicoses, the pathology of ergot alkaloid toxicoses, and ways for producers to reduce the effects of toxic endophytes.
The grass is natural hybrid derived from perennial ryegrass and meadow fescue.