( and ( ( ( ( ( ( ( an ( innermost layer ) ) , ) or ) stele ) , ) ( which ( is ( composed ( of ( layers ( of ( ( ( ( ( ( ( ( tough ( pericyclic cells ) ) , ) ( ( a ( multicellular layer ) ) ( of ( vascular ( phloem cells ) ) ) ) ) , ) ( ( a ( multicellular layer ) ) ( of xylem ) ) ) , ) or ) ( ( ( ( ( wood , ) cells ) , ) and ) ( ( an ( inner core ) ) ( that ( is called ) ) ) ) ) ) ) ) ) ) ) ) ( pith . ) ) )
(ROOT (S (CC and) (NP (NP (NP (DT an) (JJ innermost) (NN layer)) (, ,) (CC or) (NP (NN stele)) (, ,)) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (VP (VBN composed) (PP (IN of) (NP (NP (NNS layers)) (PP (IN of) (NP (NP (JJ tough) (JJ pericyclic) (NNS cells)) (, ,) (NP (NP (DT a) (NN multicellular) (NN layer)) (PP (IN of) (NP (NN vascular) (NN phloem) (NNS cells)))) (, ,) (NP (NP (DT a) (NN multicellular) (NN layer)) (PP (IN of) (NP (NN xylem)))) (, ,) (CC or) (NP (NP (NN wood)) (, ,) (NP (NNS cells)) (, ,) (CC and) (NP (NP (DT an) (JJ inner) (NN core)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN called)))))))))))))))) (VP (VBP pith)) (. .)))
and an innermost layer, or stele, which is composed of layers of tough pericyclic cells, a multicellular layer of vascular phloem cells, a multicellular layer of xylem, or wood, cells, and an inner core that is called pith.
(ROOT (S (NP (DT The) (DT the) (NN core)) (VP (VBZ is) (NP (NP (DT the) (JJ innermost) (NN layer)) (PP (IN of) (NP (DT the) (NN sun))))) (. .)))