If you look at the distribution map for hoary plantain (Plantago media) on my main page for it (see link below) you should notice something straight away if you are thinking as a naturalist should! The marker pins for sites where I have seen run along the Dorset coast and then up towards Salisbury; the limestone and chalk ridges of Dorset. Hoary plantain only occurs on calcareous soils and is a sure indicator of alkaline conditions under your feet. That in turn should set you thinking about what other plants you might see.
Plantains are not the most exciting of plants lacking lovely. colourful flowers and foliage. Instead they have a crusty looking flower on a single stem with the leaves forming a rosette at the bottom of the stem almost unnoticed. The hoary plantain does fair better than its cousins in the 'looks' stakes having a largish flower with lots of light grey hairs which makes it look very distinguished! The term hoary means greyish white and so it is quite appropriate to apply it to this plant. This colouring is sufficient to differentiate the hoary plantain from its cousins. It flowers from May until August.
Hoary plantain is edible and has long had medicinal applications with evidence to suggest it was a well used plant even in Roman times in Britain. It has been used to treat wounds and toothache with the seeds being a laxative. How effective it is I have no idea