19° 7] 



HOLM— VEGETATIVE ORGANS OF RHEXIA 



33 



i 



L 



EXPLANATION OF PLATES I AND II 



PLATE I 



Rhexia virginica 



■ 



Fig. I. Seedling, showing basal internodes, cotyledons {Cot)^ primary root 

 {R)y and a lateral root with the tuberous swelling (r). X i 



Fig. 2. A root-shoot developed from tuberous root of seedling; a lateral 

 root swollen (r) and showing bud which will develop a shoot during next season. 

 Natural size. 



Fig. 3- The underground portions of a mature root-shoot; one of the second- 

 ary roots bears a tuber. Natural size. 



Fig. 4. An old tuber with shoots. Natural size. 



Fig. 5. An old tuber with buds. Natural size. 



A 



Fig. 6. Apex of a long glandular hair. X320. 



F 



PLA TE J I 



Rhexia mariana 

 Fig. 7. Epidermis of lower face of leaf. X320. 

 Fig. 8. Epidermis of upper face of leaf. X320. 



Rhexia virginica 



Fig. 9. Glandular hair. X320. 



Fig. 10. Transverse section of the tuberous root of fig, 2, showing cork (P), 

 secondary cortex (C) with druids, leptome (Z), cambium {Cam), hadrome (iJ), 

 and protohadrome {PH). X204. 



Fig. ii. Cork of the same tuber. X320. 



Fig. 12. Cork of an older tuber, y.2^20. 



Fig. 13. Transverse section of an old tuber, showing outermost part of a 

 mestome strand; index letters as above. X320. 



Fig. 14. Central leptome strand of stem. X320. 



Fig. 15. Ventral supernumerary vein of leaf, also showing thick-walled 

 colorless tissue {Coll), leptome (L), and hadrome (if). XS^o. 



Fig. 16. Transverse Rhexia mariana section of ventral epidermis of leaf. 

 X320. 



