the fruits and leaves
can have a negative affect*
on the skin

*effect, actually, Kew Gardens!

Thanks to the Kew Gardens web page for info on Wild Strawberries!
I was not aware of this: "Once widespread, wild strawberries are categorised as near threatened in England due to changes in countryside management that have led to the dramatic decline of wildflower meadows."
Nor of this, where I found my haiku: "Wild strawberry is used in traditional remedies as a laxative and diuretic. In rabbits and guinea pigs, the wild strawberry has been used to treat constipation and in cattle to treat red-water fever. Care should be taken as the fruits and leaves can have a negative affect on the skin, gastrointestinal system or respiratory system of some individuals."
(a little puzzled over the use of "affect" and not "effect" here, but English is not my first language...)**
https://www.kew.org/plants/wild-strawberry

**Edit: after kind interest and comments, I have added a proof read version as an extra. Hopefully Kew Gardens will follow :-)