( ( Higher plants ) ( ( are ( characterized ( by ( ( a ( double fertilization ) ) ( of ( the ( female gametophyte ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJR Higher) (NNS plants)) (VP (VBP are) (VP (VBN characterized) (PP (IN by) (NP (NP (DT a) (JJ double) (NN fertilization)) (PP (IN of) (NP (DT the) (JJ female) (NN gametophyte))))))) (. .)))
Higher plants are characterized by a double fertilization of the female gametophyte.
(ROOT (S (NP (DT The) (NN embryo)) (VP (VBZ develops) (PP (IN in) (NP (NP (DT a) (NN plant)) (PP (IN inside) (NP (DT the) (JJ female) (NN plant))))) (PP (IN after) (NP (NN fertilization)))) (. .)))