IIALORAr.E.T:. (WATKR-MILKOIL FAMII.V.) 181 



1. MYRIOPHYLLUM, Vaill. Watkr-Milfoil. 



Flowers iiiuna'tious or ijolygainous Calyx of the sterile flowers 4-parted, 

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

 celled, deeply 4-lohed; stigmas 4, recurved. — Perennial aquatics. Leaves 

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

 divisions. Flowers sessile in the axils of the upper leaves, usually ah<jvo water 

 in summer; the uppermost staminate. (Name from /xvpios, a thousand, and 

 (pvWov, a leaf, i. e.. Milfoil.) 



* Staine/is 8; petals deciduous ; carpels even; leaves xvhorled in threes or fours. 



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

 tlic floral ones or bracts ; these ovate, entire or toothed, and chiejiy shorter than 

 the flowers, which thus form an interrupted spike. — Deep water, Newf. to N. 

 Eng. and N. Y., west to Minn., Ark., and the Pacific. (Eu.) 



2. M. verticill^tum, L. Floral leaves much longer than the flowers, pec- 

 tinate-pinnatifd; otherwise nearly as n. \. — Ponds, etc., common. (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, Out. and N. Y. to Fla., west to Minn, and Tex. 



4. M. SCabratum, Michx. Stem rather slender ; lower leaves pinnately 

 parted with fe^v capillary divisions; floral leaves linear (rarely scattered), pec- 

 tinate-toothed or cut-serrate ; carpels strongly 2-ridged and roughened on the back. 

 — Shallow ponds, S. New Eng. to S. C, west to Mo. and La. 



* * * Stamens 4; petals rather persistent; carpels even on the back, leaves 



chief y scattered, or wanting on 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 for al 

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

 smooth. — Ponds and ditches, Mass. to N. J. and Penn. ; also in Ind. — Var. 

 capillXceum, Torr. & Gray, has stems floating, long and very slender, and 

 leaves all immersed and capillary. Var. lim(')Sum, Torr., is small, rooting in 

 the mud, with leaves all linear, incised^ toothed, or entire. 



6. M. ten^Uum, Bigelow. Flowering stems nearly leafless and srape4ike 

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

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

 Newf. to N. Eng., west to Mich. 



2. PROSERPINACA, L. Mrrmaid-wekd. 



Flowers perfect. Calyx-tube 3-sidod,t]ie 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 ba.se, alternate leaves, 

 and small flowers sessile in the axils, solitary or 3-4 together, in summer. 

 (Name applied bv Pliny to a Polygonum, meaning pertaining to Proserpine.) 



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

 when under water ; fruit sharply angled. — Wet swamps, N. Eng. to Fla.. west 

 to Minn, and Tex. 



