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.

Descriptions of principal plant phenophases 217 Fenolog .rgo.ru : Development of fru it - fruit ripening, like flowering, passes through a certain sequence of events, and determination of fruiting onset may be a challenge. Partial petal fa ll in specific flowers indicates fru it set in them. Full petal fa ll in all flowers indicates fru it setting is at peak. The date to record as the beginning of fruit ripening is when 2-3 specimens of a species are found to bear the first ripe fruits (cones in conifers). The general traits of ripeness are the size, color and texture typical of ripe fruit. Juicy fruits (cloudberry, raspberry, rowan, cowberry, bilberry) are considered ripe when they have turned to their typical color and became soft to touch. The duration of ripening is the shortest in dry fruits, longer in fruits with fleshy pericarp (berries, drupes), and the longest in hard-shelled fruits (nuts, walnuts). Seeds in the cones of some coniferous species take even longer to ripen. Ripening of dry fruits is de termined by color change and shedding. Yet, not all species shed fruits as soon as they are ripe. Seed shedding from spruce cones happens in late winter or early spring; in years with a long and dry autumn spruce seeds may be shed in the end of the autumn. Seed dispersal in pine takes place in late April - early May on the third spring since flowering. Late May - early June is the time for seed dispersal in aspens and willows (‘fluff’ flying). The sign of fruit ripening in birch is the first winged seeds under the trees; in the legume family it is the browning and dehiscence of legumes, which split open and release seeds. Juniper fruits turn blue-black, softened and easily squashed by fingers. The indicators of fruit ripening in alder are “cones" beginning to turn brown and spread their scales. Minin A. A. (2000): The date to record as the beginning offru it ripening is when 2-3 specimens of a species are found to bear the first ripe fruits (cones in conifers). Terentjeva E. Yu. (2008): Fruit and seed setting phase - small green fruits. Beginning of seed shedding - first specimens have shed seeds. Sinel’nikova N. V. and Pakhomov M.N. (2015): Fruit setting -primordia are enlarged, but still hidden in senescing flower parts; flowers without primordia are shed. Fruit formation - fruits have acquired the size and shape typical of ripe fruits. Beginning of fru it ripening - more than a half of fruits have acquired a typical color, and fruits or seeds are easily separated from the parent plant.