li>4 ONAGRACEiE. (EVENING-PRIMROSE FAMILY.) 



1. C, JLiaicti&na, L. Stem mostly pubescent (l°-2° high); leaves ovate, 

 pointed, slightly toothed ; bracts none; hairs of the roundish 2-celled fruil bristly. 

 — Mois; woodlands. July. (Eu.) 



2. C. aBpiaaa, L. Low (3' -8' high), smooth and weak; leaves heart-shaped, 

 thin, shining, coarsely toothed; bracts minute; hairs of the obovate-oblong l-celled 

 fruit soft and slender. — Cold woods ; common northward. July. (Eu.) 



Suborder II. HALOBAGEiE. Tiie Water-Milfoil Family. 



7. PHOSEBPI1VACA, L. Mermaid-weed. 



Calyx-tube 3-sided, the limb 3-parted. Petals none. Stamens 3. Stigmas 

 3, cylindrical. Fruit bony, 3-angled, 3-cellcd, 3-secded, nut-like. — Low, peren- 

 nial herbs, with the stems creeping at the base (whence the name, from proserpo, 

 to creep), alternate leaves, and small perfect flowers sessile in the axils, solitary 

 or 3 - 4 together. 



!■ P« palustris, L. Leaves lanceolate, sharply seirate, the lower pecti- 

 nate when under water ; fruit sharply angled. — "Wet swamps. June - Aug. 



2. P. pectiaaacua, Lam. Leaves all pectinate, the divisions linear-awl- 

 shaped ; fruit rather obtusely angled. — Sandy swamps, near the coast. 



§. MYBIOPHYLLUM, Vaill. Water-Milfoil. 



Flowers monoecious or polygamous. Calyx of the sterile flowers 4-parted, of 

 the fertile 4-toothed. Petals 4, or none. Stamens 4-8. Fruit nut-like, 4- 

 celled, deeply 4-lobed : stigmas 4, recurved. — Perennial aquatics. Leaves 

 crowded, often whorled ; those under water pinnately parted into capillary 

 divisions. Flowers sessile in the axils of the upper leaves, produced above 

 water; the uppermost staminate. (Name from pvpios, a thousand, and (fivWov, 

 a leaf, i. e. Milfoil.) 



* Stamens 8: petals deciduous : carpels even : leaves whorled in threes or fours. 



1. M. spicataam, L. Leaves all pinnately parted and capillary, except 

 the, floral ones or bracts; these are ovate, entire or toothed, and chiefly shorter than 

 the flowers, which thus appear to form an interrupted leafless spike. — Deep 

 water, common. July, Aug. (Eu.) 



2. M. vea'tacillataaaia, L. Floral leaves much longer than the flowers, pec- 



tinate-pinnatifld : otherwise nearly as No. 1. — Ponds, &c. northward. (Eu.) 



* * Stamens 4 : petals ?-ather persistent : carpels 1 - 2-ridged and roughened on the 

 back: leaves whorled in fours and fives, the lower with capillary divisions. 



3. M. laeteroptaylluna, Michx. Stem stout; floral leaves ovate and 

 lanceolate, thick, crowded, sharply serrate, the lowest pinnatifid ; fruit obscurely 

 roughened. — Lakes and rivers, from N. New York westward and southward. 



4. M. scabl'atuill, Michx. Stem rather slender ; lower leaves pinnately 

 parted with few capillary divisions ; floral leaves linear (rarely scattered), pectinate- 

 toothed or cut-serrate : carpels strongly 2-ridged and roughened on the back. — Shal- 

 low ponds, from Rhode Island and Ohio southward. 



