MONOCOTYLEDONES 189 



19. PontederiacGEe. 



20. Philydracese. 



21. Xyridaceae. 



22. Mayaceae. 



23. Commelynaceae. 



Series 4. — Cahjcince. 



Character s . — Perianth herbaceou s ; inner whorl small ; 

 very rarely sub-petaloid. Ovary free. Albumen copious. 

 Order 24. Juncaceae. 

 25. Palmaceae. 



Series 5. — Nudiflorce. 

 Characters. — Perianth absent or reduced to scales or setas. 

 Ovary superior with a solitary carpel, or if of many carpels then 

 syncarpous. Ovules l-oo. Seeds most frequently albuminous. 

 Order 26. Pandanacese. 



27. Typhaceae. 



28. Aroidaceae or Araceae. 



29. Lemnaceae. 



Series 6. — Ajpocarpce. 

 Characters. — Perianth uniseriate or absent. Ovary supe- 

 rior. Carpels distinct or solitary. Seeds exalbuminous. 

 Order 30. Triuridaceae. 



31. Alismaceae. 



32. Butomaceae. 



33. Naiadaceae. 



34. Juncaginaceae. 



Series 7. — GlumacecB. 

 Characters. — Flowers in capitula or spikelets, disposed 

 under bracts or glumes ; very often imbricated, sessile ; segments 

 of perianth small, scale-like, glumaceous or absent. Ovary either 

 with one ovule, or divided into monovulate loculi. Seeds al- 

 buminous. 



Order 35. Eriocaulaceae. 



36. Desvauxiaceae. 



37. Eestiaceae. 



38. Cyperacese. 



39. Graminaceae, 



