Interesting article sheds light on evolutionary trends in the floral transcriptome.

A recently accepted paper in The Plant Journal (Yoo et al, 2010) looks at the floral transcriptome of the basal angiosperm, Nuphar advena (water lily). "Floral organs are weakly differentiated in Nuphar and also in Persea (avocado), with staminodial intermediates between stamens and perianth in Nuphar, and between stamens and carpels in Persea. Consequently, the predominantly organ-specific transcriptional programs that characterize Arabidopsis flowers (and perhaps other eudicots) are derived, and correlate with a shift toward morphologically distinct floral organs, including differentiated sepals and petals, and a perianth distinct from stamens and carpels." This is an interesting case of the challenges facing the Plant Structure Ontology as we strive to expand and describe all plants.