( Ferocious ( spines ( of ( a ( barrel cactus ) ) ) ) )
(ROOT (NP (NP (NNS Ferocious)) (NP (NP (NNS spines)) (PP (IN of) (NP (DT a) (NN barrel) (NN cactus))))))
Ferocious spines of a barrel cactus
(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)))))))))) (. .)))