ephemera

Concise Oxford English Dictionary © 2008 Oxford University Press:
ephemera /ɪˈfɛm(ə)rə, -ˈfiːm-/

▶plural noun things that exist or are used or enjoyed for only a short time.

– derivatives
ephemerist noun.

– origin C16 (orig. (as sing. n.) denoting a plant said to last only one day, or an insect with a short lifespan): pl. of ephemeron, from Gk, neut. of ephēmeros ‘lasting only a day’.