( ( ( ( The ( National Institute ) ) ( of ( ( Allergy ( and ( Infectious ( Diseases ( Allergic reactions ) ) ) ) ) ( to ( three ( native ( American plants ) ) ) ) ) ) ) ( -- ( ( ( ( ( ( ( poison ivy ) , ) ( poison oak ) ) , ) and ) ( ( ( poison sumac ) , ) ( ( all members ) ( of ( the ( plant ( genus Toxicodendron ) ) ) ) ) ) ) -- ) ) ) ( ( have ( ( been ( sources ( of misery ) ) ) ( for ( many centuries ) ) ) ) . ) )
(ROOT (S (NP (NP (NP (DT The) (NNP National) (NNP Institute)) (PP (IN of) (NP (NP (NNP Allergy) (CC and) (NNP Infectious) (NNPS Diseases) (NNP Allergic) (NNS reactions)) (PP (TO to) (NP (CD three) (JJ native) (JJ American) (NNS plants)))))) (PRN (: --) (NP (NP (NN poison) (NN ivy)) (, ,) (NP (NN poison) (NN oak)) (, ,) (CC and) (NP (NP (NN poison) (NN sumac)) (, ,) (NP (NP (DT all) (NNS members)) (PP (IN of) (NP (DT the) (NN plant) (NNS genus) (NN Toxicodendron)))))) (: --))) (VP (VBP have) (VP (VBN been) (NP (NP (NNS sources)) (PP (IN of) (NP (NN misery)))) (PP (IN for) (NP (JJ many) (NNS centuries))))) (. .)))
The National Institute of Allergy and Infectious Diseases Allergic reactions to three native American plants -- poison ivy, poison oak, and poison sumac, all members of the plant genus Toxicodendron -- have been sources of misery for many centuries.
(ROOT (S (NP (NN Poison) (NN ivy)) (ADVP (RB typically)) (VP (VBZ has) (NP (NP (CD three) (NNS groups)) (PP (IN of) (NP (NNS leaves))))) (. .)))