periodic
periodical
amphibian
angiosperm
anniversary
annual
annual holiday
aquatic plant
biannual
bicentenary
bicentennial
bimonthly
birthday
bissextile day
biweekly
catamenial
centenary
centennial
commemoration
cosmopolite
cutting
daily
decennial
deciduous plant
diamond jubilee
dicot
dicotyledon
diurnal
ephemeral
evergreen
exotic
flowering plant
fortnightly
fungus
gametophyte
golden wedding anniversary
gymnosperm
hebdomadal
holy days
hourly
hydrophyte
immovable feast
jubilee
leap year
menstrual
momentary
momently
monocot
monocotyl
monthly
name day
natal day
flora
plant
plant life
81st
city-parish
forthis
free-flowering
free-growing
half-hardy
improvable
intertribal
large-leaved
month-long
one-day
quinquennial
sandy/drained
septennial
sheep-shearing
triennial
tuberous
vote
zero-based
millennial
perennial
quadrennial