( ( ( ( Embryo-sac ( development Polygonum ) ) - ) type ) . )
(ROOT (NP (NP (NNP Embryo-sac) (NN development) (NNP Polygonum)) (: -) (NP (NN type)) (. .)))
Embryo-sac development Polygonum -type.
(ROOT (S (NP (NP (DT The) (JJ amniotic) (NN sac)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBD was) (VP (VBG sitting) (PP (IN on) (NP (NP (NN top)) (PP (IN of) (NP (DT the) (JJ flat) (NN embryo))))))))) (, ,)) (VP (VBZ envelops) (NP (DT the) (NN embryo)) (SBAR (IN as) (S (NP (PRP it)) (VP (VBZ folds))))) (. .)))