pap·pus 
(păpəs)
(păpəs)n. pl. pap·pi (păpī)
A modified calyx, composed of scales, bristles, or featherlike hairs, in plants of the composite family, such as the dandelion and the thistle.
[Latin, old man, down on certain seeds, from Greek pappos; see papa in the Appendix of Indo-European roots.]
pappose (-ōs) adj.