( ( ( The ( ( most distinct ) part ) ) ( of ( a cactus ) ) ) ( ( is ( its spines ) ) . ) )
(ROOT (S (NP (NP (DT The) (ADJP (RBS most) (JJ distinct)) (NN part)) (PP (IN of) (NP (DT a) (NN cactus)))) (VP (VBZ is) (NP (PRP$ its) (NNS spines))) (. .)))
The most distinct part of a cactus is its spines.
(ROOT (S (NP (NP (DT The) (NNS spines)) (PP (IN of) (NP (DT a) (NN cactus)))) (VP (VBP help) (SBAR (S (NP (PRP it)) (VP (VBP survive) (SBAR (IN because) (S (NP (NNS spines)) (VP (VB protect) (NP (DT the) (NN cactus)) (PP (IN from) (NP (NNS animals)))))))))) (. .)))