plenty...although americana is a kinda weird genre since it's often the same thing as either alt. country or folk rock.
calexico and justin townes earle are great recs, and besides those I'd recommend (not necessarily in order): jason isbell, phosphorescent, drive-by truckers, blitzen trapper, magnolia electric co, songs:ohia, my morning jacket, the felice brothers, alejandro escovedo, nathaniel rateliff, deer tick, dylan leblanc, centro-matic, gillian welch, dave rawlings machine, ryan adams, chuck prophet, richmond fontaine, bloodkin, lucero, the deep dark woods...
to begin with. and I interpreted americana pretty loosely.