HALORAGE^E. ( WATER-MILFOIL FAMILY.) 175 



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



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

 \h& floral ones or bracts; these ovate, entire or toothed, and chiefly shorter than the 

 flowers, which thus form an interrupted spike. Deep water: common. (Eu.). 



2. M. verticillatum, L. Floral leaves much longer than t/te flowers, pec- 

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



# * Stamens 4 : petals rather persistent : carpels 1 - 2-ridged and roughened on the 



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



3. M. heteroph^llum, Michx. Stem stout ; floral leaves ovate and lance- 

 olate, thick, crowded, sharply serrate, the lowest pinnatifid ; fruit obscurely rough- 

 ened. Lakes and rivers, from N. New York westward and southward. 



4. M. scabratum, 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. Shallow 

 ponds, from S. New England and Ohio southward. 



* * * Stamens 4 : petals rather persistent : carpels even on the back: leaves chiefly 



scattered, or wanting Qn the flowering stems. 



5. M. ambiguum, Nutt. Immersed leaves pinnately parted into about 10 

 very delicate capillary divisions ; the emerging ones pectinate, or the upper floral 

 linear and sparingly toothed or entire; flowers mostly perfect', fruit (minute) 

 smooth. Var. 1. NATANS : stems floating, prolonged. Var. 2. CAPILLA.CEUM : 

 stems floating, long and very slender ; leaves all immersed and capillary. Var. 

 3. LiM6suM : small, rooting in the mud ; leaves all linear, incised, toothed, or 

 entire. Ponds and ditches, Massachusetts to New Jersey, Pennsylvania, and 

 southward, near the coast. 



6. M. tenelllim, Bigelow. Flowering stems nearly leafless and scape-like, 

 (3' -10' high), erect, simple; the sterile shoots creeping and tufted; bracts 

 small, entire ; flowers alternate, monoecious; fruit smooth. Borders of ponds, N. 

 New York, New England, and northward. 



2. PROSERPINACA, L. MERMAID-WEED. 



Flowers perfect. Calyx-tube 3-sided, the limb 3-parted. Petals none. Sta- 

 mens 3. Stigmas 3, cylindrical. Fruit bony, 3-angled, 3-celled, 3-seeded, nut- 

 like. Low, perennial herbs, with the stems creeping at the base (whence the 

 name, from proserpo, to creep), alternate leaves, and small flowers sessile in the 

 axils, Eolitary or 3-4 together, in summer. 



1. P. pallistris, L. Leaves lanceolate, sharply serrate, the lower pectinate 

 when under water ; fruit sharply angled. Wet swamps : not rare. 



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

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



9. HIPPUBIS, L. MARE'S.TAIL. 



Flowers perfect or polygamous. Calyx entire. Petals none. Stamen one, 

 inserted on the edge of the calyx. Style single, thread-shaped, stigmatic down 

 one side, received in the groove between the lobes of the large anther. Fruit 



