In most epiphytic orchids they are rather thick-leathery or even succulent and water-storing as they have to endure frequent dry periods: remember that a tree bark dries out already a few hours after a rain storm, and the plant may have to wait for a few days for another rain shower.
(the plant; to wait; T:for a few days for another rain shower)
the plant
to wait
T:for a few days for another rain shower