Oil palm (Elaeis guineensis) is an unbranched palm, possessing a single shoot apical meristem (SAM) that may remain active for more than 100 years. Through histological analysis and 3-D reconstructions, Jouannic et al. detail the SAM structural variations that occur during the oil palm life cycle, and find that development of the SAM is characterized by a juvenile-to-mature phase transition accompanied by establishment of a zonal pattern and modified shape. SAM zonation is dynamic during the plastochron period and displays distinct features compared with other monocots.
Early-diverging angiosperms are important for studies of the origin and early evolution of the flower. Vialette-Guiraud et al. discuss the potential of the water lily Cabomba (Nymphaeales) as a model basal angiosperm, as it combines simplicity of floral structure, numerous pleisiomorphic angiosperm characters, and practical features that make it amenable to study using a broad range of molecular biological techniques. They also provide protocols for the growth and molecular analysis of Cabomba, a Cabomba flower EST database, and a genome size measurement of C. caroliniana.