Seed clearing method—This method was modified from Zindler-
Frank (1974) to retain the crystals. Seeds were dissected out of floral
buds and placed in 95% ethyl alcohol (EtOH) overnight. Older seeds
were hand sectioned longitudinally to provide thinner segments for
viewing. To dissolve and remove nonwall organic materials around the
crystals, dissected seeds were treated with 2.5% Clorox (sodium hypochlorite
5 NaOCl) for 8 h (small seeds), and for 1–2 d (older seeds).
After these treatments, cleared seeds/segments were dehydrated through
a graded EtOH series, then EtOH : xylene (1:1), pure xylene, and
mounted in Permount on slides and coverslipped. The time for each
step varied, depending upon the seed/segment size. Crystals in whole
seed/segment clearings were viewed by using a Leitz Wetzlar Orthoplan
microscope with planapochromatic lenses and fitted with polarizing filters.
Kodak Ektachrome 64T and Techpan films were used to record the
images.