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 213 finger would cause anthers to release a wisp of pollen. In the willow species pollinated by wind and insects, pollen spread by wind is minor. Hence, to identify the beginning of anthesis in such species one should touch anthers with fingertip and, if anthesis has begun, the finger would be smeared with yellowish pollen. Observations of herbaceous plants are more complex and time-con suming. In plants with flowers gathered in spikes flowering onset is recorded when anthers have emerged and shed pollen if slightly shaken. In the legume family (Fabaceae), flowering is considered to begin when there appear several flowers with an upright broad petal (banner). In plants with raceme (rosebay willowherb) or capitulum (coltsfoot) inflo rescences flowering onset is determined by the appearance of the first quite completely open flowers within inflorescences; in cloudberry, Arctic bramble - by the opening of the first flowers. Keep in mind that in some plants (dandelion, coltsfoot) flowers and inflorescences are open in the first part of the day and close in the afternoon. Terentjeva E. Yu. (2008): Flowering onset is counted from the moment the first flowers open. The methodologically impeccable approach to flow ering onset timing is to determine the dates of maturation of anthers and stigmas. Mature anthers become dehiscent and release pollen, whereas mature stigmas open and become sticky. Often, maturation of anthers and stigmas is not simultaneous. Opening of the floral envelope (perianth) is usually coupled with mat uration of stamens and stigmas, wherefore perianth opening can be commended as an indicator of flowering onset. Sinel’nikova N. V. and Pakhomov M. N. (2015): Flowering onset is indicated by the first open flowers. Within inflorescences there may be several to a half of them, while the other half would be colored flower buds. In w ind-pollinated plants (including grasses, sedges, cottongrasses) flowering is determined by the beginning of anthesis, when a wisp of pollen is produced by shaking shoots bearing male inflorescences (Minin, 2000).