( ( The trees ) ( ( are ( easily ( recognizable ( by ( ( ( their ( dense mats ) ) ( of ( thick ( , ( stick-like roots ) ) ) ) ) ( that ( ( rise out ) ( of ( the ( ( mud and ) water ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS trees)) (VP (VBP are) (ADJP (RB easily) (JJ recognizable) (PP (IN by) (NP (NP (PRP$ their) (JJ dense) (NNS mats)) (PP (IN of) (NP (JJ thick) (, ,) (JJ stick-like) (NNS roots))) (SBAR (WHNP (WDT that)) (S (VP (VBP rise) (PRT (RP out)) (PP (IN of) (NP (DT the) (NX (NX (NN mud)) (CC and) (NX (NN water)))))))))))) (. .)))
The trees are easily recognizable by their  dense mats of thick, stick-like roots that rise out of the mud and water.
(ROOT (S (NP (JJ Stilt) (JJ like) (NNS roots)) (VP (VBZ helps) (S (NP (JJ mangrove) (NNS trees)) (VP (VB rise) (ADJP (JJ high) (PP (IN above) (NP (DT the) (NN water))))))) (. .)))