Flowering plant magnoliid (2%) clades. The remaining 5 clades contain a little over 250 species in total; i.e. less than 0.1% of flowering plant diversity, divided among 9 families. The 43 most-diverse of 443 families of flowering plants by species, in their APG circumscriptions, are Of these, the Orchidaceae, Poaceae, Cyperaceae, Araceae, Bromeliaceae, Arecaceae, and Iridaceae are monocot families; Piperaceae, Lauraceae, and Annonaceae are magnoliid dicots; the rest of the families are eudicots. Double fertilization refers to a process in which two sperm cells fertilize cells in the ovule. This process begins when a pollen grain adheres to the stigma of the
Flowering Locus C Flowering Locus C Flowering Locus C ("FLC") is a MADS-box gene that in late-flowering ecotypes of the plant "Arabidopsis thaliana" is responsible for vernalization. In a new seedling "FLC" is expressed, which prevents flowering. Upon exposure to cold, less "FLC" is expressed (to a degree depending on the amount of cold), and flowering becomes possible. "FLC" is extensively regulated through epigenetic modifications and transcriptional control. The expression of "FLC" is affected by other genes including "FLK", "FCA" and "VERNALIZATION2" ("VRN2"). Wild "Arabidopsis" plants have different alleles for the "FLC" gene, which correspond to ecotypes which either (a) flower rapidly and