pappus

noun, plural pap·pi [pap-ahy] /ˈpæp aɪ/. Botany.

1. a downy, bristly, or other tuftlike appendage of the achene of certain plants, as the dandelion and the thistle.

noun plural pappi (ˈpæpaɪ)

1. a ring of fine feathery hairs surrounding the fruit in composite plants, such as the thistle; aids dispersal of the fruits by the wind

Plural pappi (păp′ī)

1. 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.