Flower Formation in Apices of Sisyrinchium bermudiana L.

Sisyrinchium bermudiana plants were grown in growth chambers under 10 hour short day regimes. Plants were removed at periodic intervals to provide inductive cycles of 2, 4, 6, 8, 10, 12, 14 and 16 weeks. Flowering (taken at the time of visible bud) was initiated best on plants receiving 10 or more weeks of short days. Scanning electron microscopy of the shoot apices at weekly intervals confirmed that the transition from vegetative to floral occurs at the 10 week short-day inductive cycle. It was also determined that stamens and tepals develop first as common stamen-tepal primordia which bifurcate to form outer tepals and stamens opposite.