Structural characterization of non-pretreated P. trichocarpa (Poplar), P. virgatum (Switchgrass: SG), A. americana leaves (AAL), A. salmiana leaves (ASL), A. tequilana leaves (ATL), and A. americana heart (AAH) biomasses. (a) Simons’ Stain results for biomass pore surface area represented by the amount of absorbed dye, mg dye/g of sample. (b) Simons’ Stain results for relative enzyme accessibility represented by ratio of absorbed large dye to small dye, [mg orange dye/g sample]/[mg blue dye/g sample]. (c) Spin-spin relaxation times (T2) of absorbed water within biomass samples produced via ILTs of CMPG T2 experiments. (d) XRD spectrum. Confocal laser scanning microscopy of AAL cell walls: bright field (e,f) and auto-fluorescence (g,h). AAL: A. americana leaves; ASL: A. salmiana leaves; ATL: A. tequilana leaves; AAH: A. americana heart; SG: Switchgrass.