( ( A plant ) ( ( ( is usually ) ( ( considered ( a weed ) ) ( ( ( when ( it ( interferes ( with ( ( beneficial uses ) ( of ( ( land or ) water ) ) ) ) ) ) ) or ) ( when ( it ( ( ( ( grows ( in ( place of ) ) ) , ) or ) ( interferes ( with ( ( the growth ) ( of ( desirable plants ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN plant)) (VP (VBZ is) (ADVP (RB usually)) (VP (VBN considered) (NP (DT a) (NN weed)) (SBAR (SBAR (WHADVP (WRB when)) (S (NP (PRP it)) (VP (VBZ interferes) (PP (IN with) (NP (NP (JJ beneficial) (NNS uses)) (PP (IN of) (NP (NN land) (CC or) (NN water)))))))) (CC or) (SBAR (WHADVP (WRB when)) (S (NP (PRP it)) (VP (VP (VBZ grows) (PP (IN in) (NP (NP (NN place)) (PP (IN of))))) (, ,) (CC or) (VP (VBZ interferes) (PP (IN with) (NP (NP (DT the) (NN growth)) (PP (IN of) (NP (JJ desirable) (NNS plants)))))))))))) (. .)))
A plant is usually considered a weed when it interferes with beneficial uses of land or water or when it grows in place of, or interferes with the growth of desirable plants.
(ROOT (S (NP (NNS Weeds)) (VP (VBP are) (NP (NP (NNS plants)) (SBAR (WHNP (WDT that)) (S (VP (VP (VBP grow) (SBAR (WHADVP (WRB where)) (S (NP (NNS people)) (VP (VBP do) (RB n't) (VP (VB want) (NP (PRP them)) (PP (TO to))))))) (CC and) (VP (MD can) (VP (VB take) (PRT (RP up)) (NP (NP (NN space) (CC and) (NN use) (NNS resources)) (SBAR (WHNP (WDT which)) (S (VP (VBZ hinders) (NP (NP (NN growth)) (PP (IN of) (NP (ADJP (RBR more) (JJ desirable)) (NNS plants))))))))))))))) (. .)))