The structure of individual variability of palynomorphological features of the genus Cestrum (Solanaceae). Typical form and deviations (morphoses)

The individual variability of morphological features of pollen of 55 species of the genus Cestrum (Solanaceae) was studied using light-optical and scanning electron microscopes. Typical pollen grains of the studied species are 3-colporate; the ora are equatorially elongated; in pollen of some species they form a continuous equatorial oral belt; the sculpture is psilate, striate, tuberculate, rugate. The scope and structure of variability of pollen morphological features (number and location of apertures and surface sculpture) in the studied samples of Cestrum species are described at the individual level and at the level of the genus as a whole. The variability of the studied pollen traits fits into continuous, regular, transitively ordered (taxon-nonspecific and rank-independent; over the boundaries of the relationship of taxa and homology of structures) geometric series. Pollen features are not informative enough to clarify the sectional division of the genus (all sections of the genus are palynomorphologically heterogeneous), although they can be used to diagnose individual species. The studied species cannot be divided into any distinct groups in accordance with the considered genus system — pollen signs overlap, their variability is parallel and transitive. The distinction of discrete features in a continuous variety is rather logical and requires a significant (from a theoretical point of view) reduction of the natural variety — the observed variability. Typical and atypical variability are combined into indivisible (continuous) and integral (ordered) series. Forms that may be typical in different taxa do not belong to different archetypes (body scheme) of different taxa, but together with atypical pollen forms are arranged in continuous and geometrically ordered transitive (parallel) morphological series. Indivisible (continuous) and holistic (ordered) series are combined typical and atypical variability in the forms of aperture arrangement. Different forms of apertures arrangement, which may be typical in different taxa, do not belong to different archetypes (the body scheme of different taxa), but, together with atypical forms of pollen, line up in continuous and geometrically ordered transitive (parallel) morphological series. The described properties of the structure of individual variability are considered from the perspective of a non-typological model of biological form (metamorphoses).