Bloom

Shepherd's bag. Flower

The development of flowers in various plants begins at a different time in their life. Some plants, mainly annuals , bloom quite early: a sprout that has barely emerged from the seed will harden in the ground and will develop several leaves (for example, a shepherd’s bag ( Capsella bursa-pastoris ), species of grouse ( Nasturtium ), alyssum ( Lepidium ) and others). Other plants bloom much later, when a young plantlet develops a strong root system and several leaves, in a word, when it is strong enough, it ripens, it accumulates reserve nutrients necessary for the development of flowers and seeds .

This maturation process can last, regardless of growing conditions, not equally long. In some plants ( perennial and annual ), the period of maturity, that is, flowering, begins within a month or two after germination, in others a year later (in many biennial plants), two and several years (in perennial woody and shrub plants).

Having matured, some plants bloom only once in their life (these are all annual and biennial plants and some of the perennials, the so-called one-period ones, for example, aloe , some palm trees ); such plants spend all their energy on the development of flowers and seeds, all the reserve nutrients that sometimes accumulate over the course of a dozen years, and, being exhausted, die.

Other plants that have reached maturity bloom from year to year (multi-period plants), reaching deep old age.

The time of appearance of the flowers and their abundance depends, of course, to a large extent on the growing conditions. Poor nutrition, and sometimes excessively plentiful food (rich in nitrogen ) delays flowering and significantly reduces the number of flowers.

The degree of flowering also depends on climatic conditions. For example, it has been observed that polar and alpine plants develop a much larger number of flowers than plants of temperate latitudes. Some polar and alpine plants are often dotted with bright flowers, which is probably due to the short growing season . A humid climate also reduces flowering and affects the brightness of the color of flowers.

Flowering begins, in fact, from the moment when the possibility of pollination (and fertilization ) arises in the developed flower, that is, when the parts of the flower participating in pollination become more or less free and accessible for exposure to pollination factors (wind, insects, water) . It follows that plants with cleistogamous flowers, especially underground cleistogamous flowers, clearly do not show flowering.

The method of flowering, the actual disclosure of flowers, depends on the structure of the flowers, on their location. In the simplest flowers, consisting of only stamens or pistils , flowering consists in the fact that the covering leaves covering the flowers ( bracts ) disperse, exposing the flowers, that is, making anthers and pistils free (even coniferous ovules from conifers ). In more complex flowers that still have a perianth , this last one way or another unfolds, not only not presenting obstacles, but more often contributing to pollination factors.

If the perianth is simple and green, that is, if its purpose is only to protect young fertilization organs, and later young seeds , then it simply opens, and parts of it partially or completely diverge from one another, making it more or less free access to the inside of the flower, and sometimes such a perianth is even discarded (in grapes , a cup in poppy ). If the perianth, in addition to protection, is also important as an organ that attracts insects and pollination mediators in general, that is, when the perianth is bright (whether it will be simple, for example, in a lily or corolla ), then it will more or less grow during flowering, and the shape it is associated with the shape, size and other characteristics of pollinators.

The blooming of the flower (mainly the perianth) occurs more or less quickly, and sometimes the movement of the parts is clearly noticeable (for example, in the donkey ( Oenothera biennis ), some orchids ), in some plants even a small rustle ( Stanhopea ) occurs.

Flowers bloom at different times, and the flowering period itself does not last the same. Some flowers open early in the morning, the ray of the rising sun (for example, Ipomaea purpurea ) barely falls on them, others open later (for example, Ivan tea at 6-7 hours, bindweed at 7-8 hours), others open at noon (for example, cinquefoil ), and others in the evening (for example, honeysuckle at 6 o’clock, Hesperis matronalis at 7-8, Nicotiana affinis at 8-9) and even at night ( Cereus nycticalus , queen of the night, at 9-10).

By the duration of flowering, flowers can be divided into one-day (day and night) and multi-day. To the first belong those whose flowering lasts several hours; they open and close either on the same day (day flowers), or open in the evening, and close at night or early in the morning on the next day (night). The data includes, for example, the following:

In multi-day flowers, flowering can last from 2 to 80 days. For example, in Epilobium collinum , Geranium pratense , garden poppy , mustard , rose, flowering lasts 2 days; in honeysuckle, Agrimonia eupatorium , bedstraw - three days; Lychnis diurna , Sedum atratum - 4 days; Digitalis purpurea , Lilium album - 6 days; buttercup 7 days; cranberries have 18 days; some orchids have even longer periods, for example, Cattleya labiata , Vanda coerulea - 30 days, Cypripedium insigne - 40 days, Oncidium cruentum - 60 days, Cypripedium villosum - 70 days, Odontoglossum rossii - 80 days.

The duration of flowering is directly dependent on the amount of pollen and the number of flowers that have developed on the same branch; this inverse relationship; the more pollen (the easier pollination), the more flowers, the shorter the flowering time.

The multi-day flowers of some plants have the ability to close at night at dusk and again in the morning, at a certain hour, to open. Such periodic closing and opening occurs during the entire flowering time, for example, in autumn saffron up to 12 days. The purpose of closure is to protect anthers from dew .

Secondary flowering is the process of flowering of plants that occurs at an unusual time for the year (later than normal normal dates) or untimely (untimely) flowering. Mostly, this is the process of flowering plants for the second time during the growing season , usually in late summer or autumn ^[3] . It can be observed in very many types of plants: annual (blooming flowers from sleeping buds in the autumn), biennial (prematurely vernalized ) and perennial (in which buds open late or before the usual flowering period) ^[4] . The causes are violations of the usual course of climatic conditions, plant damage, drought , freezing , cooling, plant aging, etc. Typically, secondary flowering proceeds normally and, in favorable conditions, ends with the formation of normal seeds or fruits.

• Flower clock
• Secondary flowering

• Kuznetsov Vl.V., Dmitrieva G.A. 8.5.1 Flowering // Plant Physiologyː Textbook. - Ed. 2nd, rev. and additional .. - M: Higher school, 2006. - S. 583-586. - 742 s. - 3000 copies. - ISBN 5-06-005703-8 .
• Flowering // Agriculture: Big Encyclopedic Dictionary / Redkol.ː V.K. Mesyats (Ch. Ed.) And others . - 2nd (reprint) ed. "Agricultural Encyclopedic Dictionary" 1989. - M: Big Russian Encyclopedia, 1998. - S. 583-584. - 656 p. - 100,000 copies. - ISBN 5-85270-263-3 .

• Rostovtsev S.I. Flowering // Brockhaus and Efron Encyclopedic Dictionary : in 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.