Anthers sessile, circular, 2-loculed, introrse, connate into a synandrium, dehiscence longitudinal.

花药无梗，圆，2室，内向，合生的为聚药，开裂纵向。

Calyx lobes 4 or 5 or rarely more, usually short, caducous or persistent, apex usually obtuse, rarely connate and then calyptrate.

萼裂片4或5或很少更多，通常短，早落或，端通常钝的，很少合生然后具帽状的。