A beautiful visual picture from Buson.
稲妻にこぼるゝ音や竹の露
inazuma ni koboruru oto ya take no tsuyu[1]
lightning flash
and the sound of dewdrops
dripping down the bamboo
—Buson[2]

In this haiku, I am guessing he means several bamboo trees, as in a bamboo grove. Is bamboo both singular and plural in English? I left it without an s because that sounds more correct to my ear. It seems to me like “bamboo” by itself it could be either one or many, but if you want to specify many you would add “trees” and put the s there, thus “bamboo trees”. But I’m not sure, so I might be creating my own grammar here. That happens sometimes.
At any rate, this is Buson at his most picturesque. He is painting us a scene with his words. We can very easily imagine this scene: the flash of lightning suddenly lighting up the bamboo trees, then darkness again and we are left with the quieter sound of dripping as the water runs down the trees, dripping here and there to the ground. It’s a lovely image, and the kind of picture that Buson excelled at.
The kigo (season word) here is lightning which is a kigo for all of autumn. Interestingly, the related word thunder is a kigo for summer. The reason my saijiki (kigo encyclopedia) gives for this difference is that in old times it was believed that lightning brought forth the rice, so it was set as an autumn kigo since that is when harvest is.