Макарова, О. А. Фенологический атлас растений / Н. В. Поликарпова, О. А. Макарова ; М-во природ. ресурсов и экологии Рос. Федерации, Федер. гос. бюджет. учреждение «Гос. природ. заповедник «Пасвик» ; [худож.: Хохлов В. А. ; пер.: Кислова О. С.]. - Рязань : Голос губернии, 2016.

Nature's calendars 203 Phases of the vegetative cycle Four groups of phases are distinguished in seasonal development of vegetative organs in higher plants: 1) Spring vegetative resumption phases. In woody plants this group includes spring ‘bleeding’, bud swelling and bud break; in herbaceous perennials - shoot bud break, emergence of sprouts (before leaf unfold ing) or first folded leaves (many monocots, umbellifers, etc.); in first-year plants - sprouts before the unfolding of first true leaves. The distinctive feature of these phases is that in this period the plants totally rely on stores for nutrition. Such phases of winter annual plants do not register. 2) Shoot/stem growth phases. Annual shoot elongation in woody plants and sprouting in herbaceous plants takes place in the first half of the growing season. In woody plants the phases are leaf development and shoot elongation; in herbaceous perennials the phases include tille r ing, stem elongation and leaf development; in monocarps in the years preceding flowering the stage would often have just one phase - leaf development. Shoot growth phases in leaf-bearing plants are considered to begin with the onset of leaf development, out-of-bud shoot growth. The end of this group of phases is determined by the cessation of shoot elongation or, in the case of short shoots, cessation of new leaf development. The exact dates when shoot elongation stops can be determined by system atically measuring shoot length. The sprouting process can be broken into sub-phases, which may be quite many, depending on the study tasks. One such sub-phase in shoot development, as applied to an individual plant, is the formation of one node: leaf and internode. 3) Summer vegetative development phase. It is the period between the end of vegetative shoot growth and preparation for winter dormancy. In woody plants this phase begins when shoot elongation is practically over and young leaves are fully developed, and in herbaceous plants it begins when the sward has re-established. 4) Phases of vegetative organs senescence (die-back). Annual plants die entirely every year (except for seeds). In the rest of plants, all or a part of the foliage or shoots die-off annually. Senescence is timed to the plants’ preparation for winter dormancy. Foliage senescence in deciduous trees