Anatomy of the Laminar Organs of Commelina erecta (Commelinaceae)

A study was undertaken to compare the anatomy of the laminar floral parts with that of the spathes and leaves of Commelina erecta L. Each flower has two types of petals and two types of sepals. In contrast to the other organs, the petals have a completely open venation system whose vein endings consist solely of modified bundle-sheath cells. Bundle sheaths of leaves and spathes, but not the floral organs, contain sclerified cells for support. The high density of hook-shaped trichomes on the outer surface of the spathe and of glandular microhairs on the inner surface might indicate protective and secretory functions, respectively. Anomalous stomatal apparatuses are more common on floral organs than on spathes or leaves. Leaves and spathes appear to have a more detailed developmental program than sepals and petals.