long-day

[lawng-dey, long-]

adjective Botany.

requiring a long photoperiod in order to flower.

Origin of long-day

First recorded in 1915–20

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for long-day

Historical Examples of long-day

With our present arrangement, we had these long-day marches every other day.
The South Pole, Volumes 1 and 2
Roald Amundsen
As he hastened out to trail the long-day bitter enemies, he was framing in his mind the preliminary answers for the coroner.
Laramie Holds the Range
Frank H. Spearman
So in general our winter work was about as restless and trying as that of the long-day summer.
The Story of My Boyhood and Youth
John Muir

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 darknessCompare short-day

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012