About this photo:

The flowers are a lovely white, but notice the spines on the stem. You don't want to touch this plant, as it has a wicked sting.

This is one of the flowers mentioned in Shakespeare, in fact, several times. An example, Henry V, Part I, Act 1, Scene 1:

The strawberry grows underneath the nettle,
And wholesome berries thrive and ripen best
Neighbour'd by fruit of baser quality:
And so the prince obscur'd his contemplation
Under the veil of wildness;

The purpose you undertake is dangerous; Why, that's certain; 'tis dangerous to take a cold, to sleep, to drink; but I tell you, my lord fool, out of this nettle, danger, we pluck this flower, safety.