The Poaceae is one of the most important Angiosperm families, in terms of morphological diversity, ecology and economic importance. Species within this family show a very wide variation in terms of salinity tolerance. Salt secretion through salt glands plays a significant role in regulating ion balance, contributing to salinity tolerance. This review focuses on salt glands in the Poaceae family and their role in the salinity tolerance. In Poaceae microhairs have been observed in all subfamilies, except Pooideae, but functioning salt glands are reported only in genera belonging to the Chloridoideae subfamily. Structural, ultrastructural and physiological features of salt glands are summarized and discussed and the use of salt glands as potential target features for improving salt tolerance of crops is considered.

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Inflorescence forms in grasses lead to a general assumption that their evolution is random. We reconstructed the ancestral inflorescence for Poaceae subtribe Eleusininae and outlined possible evolutionary pathways to test the hypotheses of (1) non-directionality in grass inflorescence evolution and (2) an evolutionary direction from complex to simpler inflorescence architectures in this lineage. By studying early stages of inflorescence and spikelet development, we investigated ontogenetic changes that may correlate with evolutionary pathways identified. The approach presented here indicates that the current diversity of inflorescences found in Eleusininae is probably a result of two distinct evolutionary pathways. The main path involves a multi-staged course with shortening of main axis internodes first, followed by a decrease in number of primary branches and florets per spikelet. We postulate that reduced elongation of the internodes may affect the apical and axillary meristems performance, which in turn promotes a decrease in the number of primary branches and floret per spikelet. Current diversity in inflorescences of Eleusininae may be a consequence of a reductive evolution. We found that the evolutionary directionality of inflorescences in Eleusininae may be associated with developmental events that affected inflorescence morphology at early stages.

Inflorescence morphology in Poaceae subtribes Hilariinae, Monanthochloinae, Boutelouinae, Scleropogoninae and Muhlenbergiinae (Cynodonteae, Chloridoideae) has been revisited recently, but inflorescence development remains largely unexplored. The aim of this study is to contribute additional information on the development of inflorescences in Cynodonteae by generating data on Distichlis, Bouteloua, Munroa, Erioneuron and Muhlenbergia and to compare them with results for other grasses. Using scanning electron microscopy images, we identified common developmental patterns among grasses and described developmental novelties for Bouteloua, Distichlis and Muhlenbergia. Novel developmental features are: the amphipetal initiation of second-order branches along the inflorescence of B. curtipendula, the elongation of the internodes of the inflorescence branches before floral development in M. asperifolius and 'Type II' unisexual flowers in D. acerosa. Variable traits among studied species are: inflorescence symmetry, direction of branch and spikelet initiation and differentiation, number of developing stamens, glume developmental patterns and timing of the arrest of gynoecium development during the formation of unisexual flowers. Our results allow us to postulate that a delicate balance of phytohormones may direct early development of grass inflorescence branching system by controlling direction of first-order branch differentiation. The approach used here provides a link between definitive structures and the underlying genetics.