Figure 1.

a) Inspired from nature, man‐made hydrogels are produced from elements extracted from the cell walls of plants, here represented by vascular plants (trees, grasses). Processing in water of plant‐based biocolloids endow hydrogels with special features that include “nature’s memory” as far as directionality, hierarchy, responsiveness, and function, all of which relate to the composition and morphology of the building blocks. The latter, termed as “biocolloids” can include polymeric assemblies derived from cellulose (see molecular structure) as well as noncellulosic components such as hemicelluloses, lignin and others. b) Subject areas of papers published since 2010 in the field of “hydrogels” in general (left), and hydrogels derived from wood‐based components (right) (Scopus search with a combination of related keywords, accessed December 2019).