A blighted tree is said to be planet-struck. Epilepsy, paralysis, lunacy, etc., are attributed to the malignant aspects of the planets. Horses are said to be planet-struck when they seem stupefied, whether from want of food, colic, or stoppage. The Latin word is sideratus.
“Evidentissimum id fuit, quod quacunque equo invectus est, ibi haud secus quam pestifero sidre icti pavebant.” —Livy, viii. 9.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894