We further
found that trichome diminution was not uniform in the
four sepals. The positions of sepals are determined in reference to the inflorescence meristem. Accordingly, an abaxial
sepal, an adaxial sepal and two lateral sepals are developed
in a flower ( Matsumoto and Okada 2001 ). Trichomes on
lateral sepals were lost fi rst, and followed by those on
adaxial sepals. Trichomes on abaxial sepals disappeared
last (Supplementary Fig. S5).