The Collaborative International Dictionary
Sleep-at-noon
Sleep-at-noon \Sleep"-at-noon"\, n. (Bot.)
A plant ( Tragopogon pratensis) which closes its flowers at
midday; a kind of goat's beard.
--Dr. Prior.
Wiktionary
sleep-at-noon
n. A plant ((taxlink Tragopogon pratensis species noshow=1)) which closes its flowers at midday; Jack-go-to-bed-at-noon.