Résumé:
The check-list, the follow-up of the phase of blooming, taking of samples, observation binocular magnifying glass and optical microscope, showed an important biodiversity represented by more than 290 of plant species listed in 60 families.
The study represents a database of the morphological and histological characteristics of the reproductive system of most abundant plant species in Constantine’s region, northeast of Algeria.
The follow-up of the development cycle and particularly the phase of bloomingof these species during successive periods (2012/2013, 2013/2014) and 2014/2015), allowed to notice the effect of certain factorson this phase and to propose on one hand a floral calendarof the region of study.
It was observed on the other hand, the effect of the climatic variations from one year to another on the blooming herself and consequently on the people allergic to the grainsof pollen.
The results obtained through this study confirm that the floral characteristics (morphological and histological) always remains necessary for the distribution of plants in groups to classify them according to the visible criteria of resemblance on one hand, and the criteria of disparity
on the other hand. This remains valid as well at the level of the family; genus, the species and even the varieties.It is necessary to add to it their stability in time.
The study revealed three ways of pollination in the fertilization of flowers:
-Anemophily (wind pollination), -Entomophily (zoo-pollination)-Gravitational pollination.
The follow-up of the phase of the blooming in the area of study suggests the existence of groups of plants. Indeed, is observed a strong link between the ecological factors such as the light period (photoperiod), the temperatures (thermo-periods) and pluviometry.
The comparison between three periods of the study, highlights that the climatic variations from one year to another one, engendered a progress (precocity) or a delay (belatedness) in the starting up of the phase of blooming of certain species what rang negatively on the yield because
the spring frost in the first case and of the drought of the end of cycle in the second case.
From the point of view human health, it is noticed that the average of infringement by the allergy in man coincides with the density of blooming of plants pulling the distribution of the grains of pollen in the air.
