239 



blades rounded at the apex and tapering into a short petiole, 

 three-nerved. Style as long as or longer than the fruit, erect, 

 deciduous or persistent. Fruit very small, sessile or on a minute 

 peduncle, entirely unlike that of any other species, being only 

 about I mm. long by ^ mm. broad, the lobes separated by a deep 

 and broad apical notch, the groove between them small, the 

 margins obtuse and wingless, contracting at the base into a 

 raised, gibbous projection. The dried plant has a fragrance like 

 that of No. I. 



Florida, Arkansas, Louisiana, Texas. Also in Cuba (Wright., 

 Rugel, No. 234). 

 3. Proserpinaca. L. Act. Up. 81 (1741). 



Well-known marsh or aquatic plants readily recognized by 

 their three-celled bony triquetrous fruit. It should be noted, 

 however, that the flowers are in rare cases four-parted, and when 

 this occurs, the fruit is four-gonous, four-celled and four-seeded. 

 The inflorescence is in the axils of the emersed leaves. Two 

 species only are known, confined to North America. 



Emersed leaves linear or linear-lanceolate, sharply serrate, 

 the submerged pectinate or pectinate-pinnatifid. Fruit 

 sharply three angled, the faces concave and usually 

 smooth. I. P. paliistris. 



Leaves all pinnate or pinnatifid. Fruit smaller, angles 

 obtuse, the faces flat or slightly convex, apt to be 

 wrinkled or tuberculate. 2. P. pecti7tata. 



1. P.palustris. L. Sp. PI. 88 (1753). 



Trixis palustris. Gaert. De Fruct. ii5,t. 24 (1788). 



The submerged plants of this species may be distinguished 

 from those of the following by the fact that the segments are 

 commonly denticulate, and bear minute black spines in their 

 axils, while this seldom occurs in the other. 



Common in Canada, New England south to Florida, New 

 Mexico and Gautemala. west to Minneapolis and Iowa, Cuba 

 (Wright). 



2. P. pectinata. Lam. 111. t. 50, f i (1791). 



P.pectmacea. Torr. and Gray Fl. i, ^6 (1838). Gray Man. 



Ed. 6 182 (1890) not Lam. 

 This plant grows about as high as the preceding (20-50 cm.) 



