126 The Waterlilies. 



In order to present a tabular view of species and subgenera the 

 following synopsis and key are inserted. The genus Nymphaea divides 

 readily into two main divisions, which are subdivided into five subgenera. 



Group I. Nymphaeae apocarpiae. Subgenus (i) Anecphya. (2) Brachyceras. 



Group II. Nymphaeae syncarpiae. Subgenus (3) Castalia. (4) Lotos. (5) Hydrocallis. 



Analytic Key. 



Carpels free at sides, i. e., walls between ovary cells double (Fig. 40) {Nymphaeae 



apocarpiae) 1 



Carpels fused at sides, i. e., walls between ovary cells single (Fig. 40) {Nymphaeae 



syncarpiae 13 



1 . Carpellary styles wanting ; stamens unappendaged (Anecphya) N. gigantea 



1. Carpellary styles present, thick and fleshy ; stamens appendaged (Brachyceras) 2 



2. Flowers yellow 3 



2. Flowers never yellow 4 



3. Leaves 4 to 6 cm. across ; veins inconspicuous N. sulfurea 



3. Leaves 20 to 25 cm. across ; veins very prominent N. siuhlmannii 



4. Leaves entire or nearly so 5 



4. Leaves dentate or crenate 10 



5. Leaves narrowly elliptic (twice as long as broad) , blotched N, ovalifolia 



5. Leaves ovate or orbicular 6 



6. American species ; flowers pale violet N. elegans 



6. African species 7 



7. Mature leaves bulbilliferous N. micrantha 



7. Not bulbilliferous 8 



8. Leaves deep purple beneath A^. calliantha 



8. Leaves green or purplish-green beneath , spotted with black 9 



9. Petals s to 10 ; stamens 11 to 16 N heudelotii 



9. Petals 14 to 20 ; stamens 50 to 75 N. caerulea 



10. Flowers white 11 



10. Flowers blue or pink 12 



11. Petals narrow, acute ; leaves pure green beneath N. flavo-virens 



11. Petals elliptic, obtuse ; leaves black-spotted beneath N. ampla 



12. Petals 20 to 30 ; stamens 150 to 275 N. capensis 



12. Petals 1 1 to 14 ; stamens 33 to 55 A'', stellata 



13. Sepals prominently veined ; styles linear ; leaves spinose-dentate (Lotos) 14 



13. Sepals obscurely veined ; outer filaments petaloid 17 



14. Leaves 10 to 15 cm. long, thin and membranous N. zenkeri 



14. Leaves 20 to 25 cm. in diameter, stiff ; venation very prominent 15 



15. Flowers red ; leaves bronzy N. rubra 



15. Flowers white 16 



16. Leaf orbicular, smooth or finely puberulent beneath N. lotus 



16. Leaf ovate, densely pubescent beneath N. pubescens 



17. Styles clavate ; flowers nocturnal (Hydrocallis) 18 



17. Styles ligulate ; flowers diurnal (Castalia) 26 



18. Sepals and petals long acuminate A^. oxypetala 



18. Sepals and petals acute or obtuse 19 



19. Leaves sinuate N. rudgeana 



19. Leaves entire 20 



20. Petiole bearing a ring of long hairs at top A'', amazonum 



20. No ring of hairs at top of petiole 21 



