WordNet sense 1 ((used especially of vegetation) having lost all moisture):

sere, shriveled, dried-up, shrivelled, withered

WordNet sense 2 (free from liquid or moisture; lacking natural or normal moisture or depleted of water; or no longer wet):

dry

WordNet sense 3 (become superficially burned):

scorch, singe

WordNet sense 4 (burn slightly and superficially so as to affect color):

blacken, char

WordNet sense 5 (cause to wither or parch from exposure to heat):

parch