Lignin, the largest source of sustainable aromatics, is crucial for plant structural integrity, growth and development, and resistance to pathogens. Lignin derives primarily from the monolignols that differ in their degree of aromatic methoxylation ortho to the phenol but, as ever more component monomers are discovered, lignin can no longer be regarded as deriving from just these three monomers (Fig. 1). Pathway intermediates such as the hydroxy¬cinnam¬aldehydes and their derived hydroxybenzaldehydes, and additional products of truncated biosynthesis such as caffeyl and 5-hydroxy¬coniferyl alcohols, are now established lignin monomers in wild-type and engineered plants. The array of acylated mono¬lignols continues to expand. Game-changing findings have demonstrated that phenolics from alternative path¬ways, including flavonoids and hydroxystilbenes, are also involved in lignification, expanding the traditional concept. Beyond the basic science intrigue, these findings propound exciting new avenues for valorizing lignins, or for producing more readily extractable/depolymerizable lignins, in crop and bioenergy plants. Delineating the components that plants are already conscripting for lignification and detailing new components they may be induced to utilize are advancing this area. The pace of advancements in genetic methods is not parallelled in other areas. Organic syntheses to produce the compounds required as enzyme substrates and products, to establish the nature of intermediates, to delve into reaction mechanisms, and as models to structurally assign peaks in complex NMR spectra, are of course advancing, but all but the simplest syntheses require significant skills in the art. Elucidation of structural details and process mechanisms nevertheless remains crucial to revealing how we might progress toward improving the value of plant resources. Diagnostic chemical analyses, and NMR methods in particular (Fig. 2), coupled with data from strategic synthetic compounds, remain key. This presentation will attempt to highlight the value of such methods as integral to tree biotechnology and sustainable forest tree utilization.