Figure 4From: Traits of seasonal dimorphism associated with adaptation to cold stress in Origanum dictamnus L. (Lamiaceae) Origanum dictamnus. Ultrastructure of mesophyll cells of winter leaf (A) and summer leaf (B). In winter leaf, chloroplasts (cp) bear grana (g) with a few thylakoids and occasionally individual starch grains (sg). Vacuoles (v) are filled with fine-granular phenolics. In summer leaf, chloroplasts contain many multi-thylakoid grana and numerous starch grains. Vacuoles are devoid of phenolics. Bars in μm.Back to article page