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. – 235 с. : цв. ил., карты, табл.

Nature's calendars 199 4. Herbaceous plants The sites to be chosen for phenological monitoring of herbaceous plants are those where a species occurs frequently. In rosebay willowherb flowering begins from the lower part of an inflorescence - the onset of this phase is determined by the opening of the first flowers. Flowering onset in globeflower is determined by the yellowing of the first flowers. In fact, this species doesn’t ever fully open its flowers, but sepals, which are closed tightly in flower buds, turn yellow at the flowering onset and get slightly separated. The dates of flowering onset in individual plants and fu ll flowering (>50%) are to be recorded.