The "Lowly" Thistle?

Late August presents all sort of weeds that might work equally well in a flower bed. This thistle, when viewed up close, has petals as delicate as threads and in a lovely shade of lavendar.

I wonder how we came to call this a weed? I suppose the fact that it survived the drought and managed unattended while the exotics died even when given their daily drink made all the difference. This thistle will sport some thorns later and the plant itself is spindly and lank. But think of the orchid! That something this beautiful can bloom in some hidden corner of the field, without cultivation, without fertilizer, without regular watering, makes it all the more special to me.