Mammoth Uncensored Word List:
21 words ending with rt, 11 letters long

bladderwort brotherwort cotransport counterfort counterpart gentianwort maudlinwort postconcert purpleheart rupturewort seroconvert slipperwort sparrowfart sparrowwort staggerwort standerwort streetsmart sulphurwort swallowwort undercovert underreport