e·phem·er·al 
(ĭ-fĕmər-əl)
(ĭ-fĕmər-əl)adj.
1. Lasting for a markedly brief time: "There remain some truths too ephemeral to be captured in the cold pages of a court transcript" (Irving R. Kaufman).
2. Having a short lifespan or a short annual period of aboveground growth. Used especially of plants.
n.
Something, especially a plant, that is ephemeral.
[From Greek ephēmeros : ep-, epi-, epi- + hēmerā, day.]
e·phem′er·ali·ty, e·phemer·al·ness n.
e·phemer·al·ly adv.