Cover illustration: The cover photographs illustrate features of microsporogenesis in Allium ursinum. These features are typical of the higher Asparagales clade, with intersporal wall formation through a centrifugal cell plate (top line) leading to tetragonal tetrads with apertures in a polar position (bottom line, left). This developmental pathway results in the formation of monosulcate pollen grains (bottom line, right). See Penet et al. (pp. 331-343).
[Table of Contents]