The stems, petioles and lower surface of the leaves are heavily coated with 

 a viscid, gluey jelly. 



According to Mason (Fl. Marshes Calif. 491. 1957), Tokura observed in Japan 

 that the flowers of this species open on two successive days. On the first day the 

 flower is elevated above the water about 6 A.M. and opens within an hour, during 

 which time pollination is effected. The flower closes at about 9 A.M. and is then 

 withdrawn beneath the water. On the next day the same flower is again pushed 

 even higher above the water surface. The stamens then dehisce, and after a few 

 hours the flower is again withdrawn, never to emerge again. 



5. Nelumbo Adans. Sacred Bean 

 Represented in both hemispheres by one species each. 



1. Nelumbo lutea (Willd.) Pers. Yellow^ lotus, water-chinquapin, pond-nut. 

 Fig. 447. 



Aquatic herb with slender rhizomes rooted in mud; leaves orbicular, centrally 

 peltate, floating or mostly raised above the water on long stout petioles, to 7 dm. 

 in diameter, with the center depressed or cupped; peduncles stout, rising to about 

 1 m. above the water surface, the solitary pale-yellow flower to 25 cm. broad; 

 sepals and petals numerous, commonly 20 or more, scarcely differentiated, the 

 outermost (external in the bud) green and sepaloid; stamens numerous, spirally 

 inserted and closely surrounding the pistils; anthers antrorse, tipped with a slender 

 hooked appendage; fruiting receptacle prolonged, obconic, to 1 dm. in diameter, 

 the numerous 1-ovuled ovaries sunk in small pits on its flat truncate summit; 

 fruit nutlike, indehiscent, each separately embedded in the accrescent receptacle, 

 about 1 cm. in diameter. 



In quiet water of ponds and sluggish streams in e. Okla. (Atoka, Love and 

 McCurtain cos.) and the e. third of Tex., May-July; from Fla. to Tex., n. locally 

 to s. N.E., N.Y., s. Ont., Minn, and la. 



The farinaceous storage tubers along the rhizome are edible as well as the 

 seeds. 



Fam. 60. Ceratophyllaceae S. F. Gray Horn wort Family 



Submersed aquatic rootless herbs, with a slender primary stem and scattered 

 lateral branches; leaves whorled, sessile, finely dissected; flowers minute, unisexual, 

 without a perianth, solitary and sessile in leaf axils, subtended by an 8- to 12-cleft 

 involucre in place of a calyx; stamens 12 to 16, the filaments short, the rather 

 large anthers terminating in 2 or 3 sharp points; pistillate flower consisting of a 

 simple 1 -celled ovary with a suspended orthotropous ovule; fruit an achene, 

 beaked by the slender indurated style. 



A monotypic family. 



1. Ceratophyllum L. Hornwort. Coon-tail 



Characters of the family; plants olive-green; leaves usually 1- to 4-dichotomously 

 dissected into filiform to narrowly linear divisions. 



About 10 species that are widely dispersed. Our species are highly tolerant of 

 conditions that prove disastrous for many species of hydrophytes, such as fluctuat- 

 ing water levels and turbidity. When pieces break from the mother-plant they 

 function as new plants. 



1 . Leaves usually forked 1 or 2 times, the division conspicuously serrate on one 

 side; achenes without lateral spines 1. C. demersum. 



1. Leaves usually forked 2 to 4 times, the divisions entire or only obscurely 

 serrulate; achenes with 3 to 5 lateral spines 2. C echinatitm. 



912 



