long-day

[ lawng-dey, long- ]
/ ˈlɔŋˈdeɪ, ˈlɒŋ- /

adjective Botany.

requiring a long photoperiod in order to flower.

Origin of long-day

First recorded in 1915–20

Example sentences from the Web for long-day

British Dictionary definitions for long-day

long-day

adjective

(of certain plants) able to mature and flower only if exposed to long periods of daylight (more than 12 hours), each followed by a shorter period of darkness Compare short-day