POLYPETALOUS EXOGENOUS PLANTS. 153 



6. NELUMBO FAMILY. Order, Nelumbiace^. 



Herbs aquatic, prostrate rootstocic, leaves radical, l°-2° in 

 diameter, peltate orbicular. Flowers large, pale yellow, 

 solitary, on long upright scapes, 4-5 sepaled ; petals nu- 

 merous, arranged in many rows, as are also the stamens ; 

 ovaries separate, each with a simple style and stigma, be- 

 coming in fritit 1 -seeded nuts half sunk in the hollows 

 of the large torus, the seeds with largely developed embryo 

 and no albumen. 



N. LLTEUM (Water Chinquepin). Aquatic herbs, with 

 peltate leaves depressed in the center, and solitary, hypogy- 

 nous flowers, 5-8' wide, pale yellow. Eagle Lake, near 

 Columbus. 



7. WATER-SHIELD FAMILY. Order, Cabombace^. 



Sepals and petals 3-4. Stamens 6-18. Ovaries 2-oo. 

 Capsule 1-3 seeded, indehiscent. Stems filiform, branch- 

 ing. Submerged leaves opposite, divided into numerous 

 filiform flattened segments ; floating ones peltate, entire. 

 Floivers small, in the axils of the floating leaves. 



C. Cakoliniana. Floating leaves oblong Mhq^y -, flo2uers 

 white. Ponds and still water. Stem 2°-4° long. June- 

 August. 



BRASENIA. Water-Shield. 



Sepals and petals 3-4. Stamens 12-18, anthers exserted. 

 Ovaries 4-18. Leaves all peltate and entire, alternate 

 oval, on long petioles. Floivers axillary on elongated pe- 

 duncles, dull purple. 



B. PELT ATA, Pursh. Stem, petioles, and lower surface 

 of the leaves coated with a gelatinous exudation. Ponds 

 and slow-flowing streams. 



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