Fig. 4.

Seeds after mechanical scarification test visualized with a stereomicroscope. After mechanical scarification, the mucilage envelope (a–g, arrow) was lost to varying degrees in diaspores of different plant species. (a) Linum usitatissimum and (b) Lepidium sativum with some mucilage on the seed surface. (c) Plantago lanceolata seeds without mucilage. (d) Plantago ovata seeds with some mucilage residues. (e) Plantago psyllium seeds with very small residues of mucilage (arrow). (f) Ocimum basilicum with the entire envelope preserved on the diaspore surface. (g) Salva hispanica the mucilage is completely missing. Non-mucilaginous seeds had different mechanical damages (arrow). (h) Seeds of Amaranthus albus had some small scratches on the epidermis. (i) Breaks and fractures of Nigella sativa seeds. (j) Brassica napus with fractured seed coat and visibly damaged seed coat