( They ( ( lack ( ( the structures ) ( that ( ( ( characterize ( vascular ( and ( nonvascular plants ) ) ) ) and ) ( are ( classified ( in ( the ( kingdom Protista ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP lack) (NP (NP (DT the) (NNS structures)) (SBAR (WHNP (WDT that)) (S (VP (VP (VBP characterize) (NP (NN vascular) (CC and) (NN nonvascular) (NNS plants))) (CC and) (VP (VBP are) (VP (VBN classified) (PP (IN in) (NP (DT the) (NNP kingdom) (NNP Protista)))))))))) (. .)))
They lack the structures that characterize vascular and nonvascular plants and are classified in the kingdom Protista.
(ROOT (S (NP (NNP Moss)) (VP (VBZ is) (VP (RBS best) (VBN classified) (PP (IN as) (NP (DT a) (NN nonvascular) (NN plant))))) (. .)))
Moss is best classified as a nonvascular plant.