Flowering Biology And Phenological Rhythms Of Phlomoides Anisochila And Phlomoides Sogdiana In The Nuratau Mountains

Abstract

The study presents a comparative analysis of flowering biology and phenological rhythms of the rare and endemic species Phlomoides anisochila (Pazij & Vved.) Salmaki and Phlomoides sogdiana (Pazij & Vved.) Salmaki under the natural conditions of the Nuratau Mountains. Field observations were conducted during 2019–2023 in ten subpopulations, with detailed seasonal and daily flowering records obtained in five subpopulations of each species. Flower opening, duration of individual flowers, total flowering period, vegetation onset, bud formation, seed maturation, air temperature and relative humidity were recorded using established phenological and reproductive-biology methods. The results show that P. sogdiana starts vegetation slightly earlier and flowers from late April to the first decade of May, while P. anisochila generally starts flowering in the first decade of May. The total flowering period was 16–21 days in P. sogdiana and 14–17 days in P. anisochila. Maximum daily flower opening occurred around 12:00–14:00, and the dynamics were more closely associated with increasing air temperature than with relative humidity. The vegetation period lasted 150–155 days in P. sogdiana and 155–160 days in P. anisochila. The field results also indicate that the previously published June–July flowering period for P. anisochila does not correspond to the current phenological pattern in the studied populations. These findings provide a basis for monitoring, conservation planning and ex situ propagation of the two species.