A dryad is a tree nymph, that is a female spirit of a tree, in Greek mythology. In Greek drys signifies "oak". Thus dryads are specifically the nymphs of oak trees, though the term has come to be used for all tree nymphs in general. They were normally considered to be very shy creatures, except around the goddess Artemis, who was known to be a friend to most nymphs.
Capricorns are particular with who they take in as friends. Even if a Capricorn tends to make friends easily, they do not see them as friends, but rather someone who they just socialize with on occasion. Those who are seen as friends by Capricorns hold their intense loyalty.