2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68397This paper uses dualities between facet ideal theory and Stanley-Reisner theory to show that the facet ideal of a simplicial tree is sequentially Cohen-Macaulay. The proof involves showing that the Alexander dual (or the cover dual, as we call it here) of a simplicial tree is a componentwise linear ideal. We conclude with additional combinatorial properties of simplicial trees.15 pages, 15 figuresCommutative AlgebraCombinatorics13;05text