A hay(na)ku consists of a three-line stanza, where the first line has one word, the second line has two words, and the third line has three words. You can write just one, or chain several to hay(na)ku ...
April
cooling warming
days brimming green
Clouds
tumble gray
bring welcome rain
Earth
waking slowly
smells of geosmin
Spring
flowers unfold
reflect sun's sheen
