The Collaborative International Dictionary of English v.0.48:
Puberulent \Pu*ber"u*lent\, a. [See Pubis.] (Bot.) Very minutely downy. [1913 Webster]WordNet (r) 3.0 (2006):
puberulent adj 1: covered with fine soft hairs or down; "downy milkweed seeds" [syn: downy, pubescent, puberulent, sericeous]