PLATE XI.— WHITE WATER-LILY (Nymphaea alba) and YELLOW WATER-LILY (Nuphar luteum). 



These are water-plants, growing in lakes or ponds, with floating leaves and large solitary flowers. The leaves and flowers are borne 

 on long stalks, so as to reach the surface of the water, and the stalks are permeated by large air-cavities. 



The "White Water-lily is specially interesting, as showing a gradual passage from Sepal to Petal and from Petal to Stamen. 

 The Yellow Water-lily has an alcoholic odour like brandy, hence it sometimes gets the name of brandy-bottle. 



Flower — 



Fig. 1. Flower-bud, showing four Sepals, green on the outside. 



Fig". 2. Partially opened Bud, halved from below upwards. 

 Flower-stalk with air-cavities. 

 Sepals, less green than in unopened bud. 

 Petals and Stamens apparently inserted on Ovaries, but really attached to Receptacle, which is developed around, 



and adherent to the carpels. 

 Carpels with ovaries, partly above and partly below insertion of stamens. 



Diagram I. — Calyx, of four Sepals. 



Corolla, of numerous Petals, gradually getting smaller as they approach the Stamens. 

 Andrcecium, of numerous Stamens. 

 Gyncecium, of numerous Carpels. 



Fig. 3. Flower-bud of Yellow "Water-lily showing five greenish-yellow Sepals. 



Fig. 4. Bud halved lengthways showing superior Ovary. 



Diagram II. — Calyx of five Sepals. 



Corolla, of a variable number of Petals, often thirteen. 

 Andrcecium, of numerous Stamens. 

 Gyncecium, of numerous superior Carpels. 

 Foliage- and Floral- Leaves — 



Fig. 5. Foliage-leaf, large and heart-shaped. 



Fig. 6. Floral leaves of White Water-lily, showing transition from Sepal to Petal. 



(a.) Sepal, quite green. 



(6.) Petal, white, but otherwise resembling sepal. 



(c.) Regular Petal 



Fig. 7. Stamens, showing transition from petals to Stamens, 



(a.) Stamen, which is essentially a petal-bearing anther. 

 (6.) Regular stamen. 



Fruit and Seed — 



Fig. 8. The Fruit consists of the numerous carpels, surrounded by a fleshy Receptacle upon which the petals and stamens were 

 spirally arranged. 



It ripens under water and afterwards splits up irregularly to allow the escape of the seeds. 



Fig. 9. Vertical section of Seed. 



The Seed contains a small Embryo with large Endosperm. This endosperm is not only developed as usual in the 

 Embryo-sac, but Nucellus outside the embryo-sac also becomes loaded with nutritious matter, and this is some- 

 times called Perisperm. 



CLASSIFICATION. 



Class. — Dicotyledon. 

 Division. — Polypetalae. 

 Sub-division. — Thalam i florae , 

 Order. — Nymphaeaceae. 



Water-plants. 



Leaves, usually large and floating. 



Flowers, regular. 



Petals and Stamens, indefinite. 



Carpels, indefinite. 



Fruit, berry-like. 



