Fig. 3.

Cluster analysis performed on the hyperspectral dataset of spruce cuticle (same as shown in Fig. 2). a, b Two outer lipidic clusters (1 and 2) are distinguinshed. c, d Subclustering the lower lipidic layer displays the Calcium oxalate accumulation (see also Additional file 1: Fig. S1). e–h Epidermal layer is divided into three clusters based on changes in amount and composition of aromatic components and carbohydrates