Is it ensure, insure, or assure?
Plural pappi (pāp'ī)
A structure made of scales, bristles, or featherlike hairs that is attached to the seeds (called cypselae) of plants of the composite family and that aids in dispersal by the wind. The downy part of a dandelion or thistle seed is a pappus. The pappus is derived from a modified calyx.