PLATE 97 



Powdered Horehound {Marrubium vulgare, L). 



I. Epidermis of leaf showing the wavy epidermal cells, stoma, and a 

 clustered hair. 2. Surface view of the petal epidermis. 3. Non-glandular 

 hair from the calyx or corolla. 4. Long, thin-walled, twisted, non-glandular 

 hairs from the leaves and stem. 5. Unicellular non-glandular hair from the 

 tube of the corolla. 6. Glandular hairs with a one-celled stalk and with two 

 secreting cells divided by vertical walls. 7. Surface and side view of the 

 eight-celled glandular hairs. 8. Conducting cells. 9. Fibres from the stem. 

 jo. Pollen grains. 



