OF NAIAS GRAMINEA^ VAR. DELILEI. 73 



Plate VI. 

 Figs. 6-8. Arrangement of the cells of the marginal spines on the leaf of: — 

 (6) N.flexilis, (7) N. graminea, (8) iV. minor and N. argida. From 

 Dr. Alexander Braun's sketches in 'Journal of Eotany,' 1864. 

 vol. ii. p. 275. 

 9. Form of sheath at base of leaf of N. minor. From ' Compendio 

 della Flora Italiana ' of Oesati, Passerini, and Gibelli, tav. xxviii. 

 fig. I n. 

 10-14. Form of sheath at base of leaf of : — (10) N.flexilis, {ii)N. minor, 

 (12) JV. minor, var. setacea, (13) N. falciculata, and (14) N. gra- 

 minea. All copied from Dr. A. Braun's woodcuts in ' Journal of 

 Botany,' 1864, vol. ii. p. 274. 



15. Male flower of N. tenuifolia, E. Br. ; enlarged -V". From Magnus's 



' Beitrage,' plate iv. fig, 5. 



16. Anther of iV. mryor, with the perianth reflexed; enlarged. From 



' Genera Plantarum Florae Germanic^,' Th. Fr. Lud. Nees ab 

 Esenbeck, fasc. vi. Naias, fig. 5. 



17. Male flower oiN. minor; enlarged. Nees ab Esenbeck, I. c. fig. 24. 



18. Transverse section of male flower 0I N. major. Nees ab Esenbeck, 



I. c. fig. 7. 



19. Pollen of N. major; enlarged. Nees ab Esenbeck, I. c. fig. 8. 



20. Male flower of N. major, with the perianth drawn back ; enlarged. 



From ' Iconographia familiarum naturalium regni vegetabilis,' 

 Dr. Adalbert Schnizlein, Heft v. pi. 71, fig. 4. 



21. Vertical section of male flower of N. major ; enlarged. Schnizlein, 



I. c. fig. 6. 



22. Male flower of N. major, showing the separation of the perianth 



from the anther ; enlarged. Schnizlein, I. c. fig. 7. 



23. Vertical section of a male flower of N. major. From ' Compendio 



della Flora Italiana,' I. c. fig. i b. 

 24 & 25. Dehiscence of the perianth of N. major, after the observations 

 of Braun; enlarged. Nees ab Esenbeck, I. c. figs. 9 & 10. 



26. Grains of pollen of N. major, with fovilla ; enlarged -^f ^. From 



' Compend. Fl. It.' I. c. fig. i d. 



27. Vertical section of a male flower of N. minor, AU. ; enlarged. 



' Compend. Fl. It.' I. c. fig. i e. 



28. Male flower of N. major; enlarged f. 'Compend. Fl. It.' I.e. 



fig. I a. 



29. Base of leaf of N. major, with the sheath opened. Intravaginal 



scales at the base of the sheath, one on each side ; enlarged f . 

 ' Compend. Fl. It.' I. c. fig. i m. 



30. Intravaginal scale of N. major ; enlarged \. ' Compend. Fl. It.' I. c. 



fig. 1 0. 



Plate VII. 



31. Transverse section of the middle of the leaf of N. graminea, Del. 



enlarged -\^. Magnus, 'Beitrage,' pi. vi. fig. 3. 



