en :
fr :
Xylem cells are the following:
vessels or tracheids. Vessels are told perfect when there is no transverse wall and when all elements are joined together to reach a length that can reach many meters. Tracheids are imperfect vessels because they have a transverse wall with a lumen more or less important. Tracheids are present in basal (primitive) vascular plants such as Ferns and allies, or Gymnosperms.
APG II (Angiosperm Phylogeny Group) (10 galeries photos)
Album Herborisation
Orchidées (Orchidaceae, Asparagales, Monocots)
Fruits complexes
Fruits multiples