VOL. II.] 



PINK FAMILY. 4! 



i. Scleranthus annuus L. Knawel. German 

 Knotgrass. (Fig. 1524.) 



Scleranthus annuus L. Sp. PI. 406. 1753- 



Much branched from long and rather tough roots, the 

 branches prostrate or spreading, 2> / ~5 / l n g> roughish- 

 puberulent or glabrous. Leaves subulate, 2 // -i2 // long, 

 ciliate, light green, often recurved, their bases membran- 

 ous at the junction; tube of the calyx lo-angled, rather 

 longer than the lobes, usually glabrous, the lobes some- 

 what angled on the back and their margins incurved. 



In fields and waste places or on dry rocks, Quebec and On- 

 tario to Pennsylvania and Florida, mostly near the coast. 

 Naturalized from Europe. Very common in parts of the 

 Eastern and Middle States. March-Oct. 



Family 22. NYMPHAEACEAE DC. Propr. Med. Ed. 2, 119. 



WATER LILY FAMILY. 



1816. 



Aquatic perennial herbs, with horizontal rootstocks, floating, immersed or 

 rarely emersed leaves, and solitary axillary flowers. Sepals 3-5. Petals 5-00 . 

 Stamens 5-00 ; anthers erect, the connective continuous with the filament. Car- 

 pels 3-00 , distinct, united, or immersed in the receptacle. Stigmas distinct, or 

 united into a radiate or annular disk; ovules i-oo , orthotropous. Fruit inde- 

 hiscent, separate or coherent. Seeds enclosed in pulpy arils, or rarely naked; 

 cotyledons fleshy; hypocotyl very short. 



Eight genera and about 33 species, of wide geographic distribution in fresh-water lakes and 

 streams. 



Sepals and petals 3; stamens 6, hypogynous; carpels distinct; ovules few. 



Leaves dissected, excepting the small floating ones. i. Cabomba. 



Leaves peltate, entire, floating. 2. Brasenia. 

 Sepals 4-6; petals numerous or several; carpels united; ovules numerous. 



Petals small or minute; stamens hypogynous. 3. Nymphaea. 



Petals large, numerous; stamens epigynous. 4. Castalia. 

 Sepals 4-5; petals numerous; carpels distinct, immersed in the receptacle; ovule I. 5. Nelumbo. 



i. CABOMBA Aubl. PI. Guian. i: 321. 1775. 



Stems slender, coated with gelatinous matter, branching. Leaves petioled, peltate, the 

 floating ones small, entire; submerged ones opposite, palmately dissected into numerous 

 capillary segments. Flowers small, white or yellow. Sepals and petals 3. Stamens 6; fila- 

 ments slender; anthers extrorse. Carpels 2-4. Stigmas small, terminal; ovules commonly 

 3, pendulous. Fruit coriaceous, indehiscent, about 3-seeded. [Guiana name.] 



A genus of 2 or possibly 3 species, natives of the warmer parts 

 of America. 



i. Cabomba Caroliniana A. Gray. Cabomba. 

 Carolina Water-shield. (Fig. 1525.) 



Cabomba Caroliniana A. Gray, Ann. Lye. N. Y. 4: 47. 1837. 



Stem several feet long, branching. Submerged leaves op- 

 posite or sometimes verticillate, petioled, I'-a' broad, cen- 

 trally peltate, repeatedly divided; floating ones alternate or 

 opposite, linear-oblong, 6 // -io // long; flowers long-peduncled 

 from the upper axils, 6 // -8 // wide, white, or yellow at base 

 within; petals obovate; ripened carpels 3, separate, flask- 

 shaped. 



In ponds and slow streams, southern Illinois to North Carolina, 

 south to Florida and Texas. May-Aug. 



