VOL. II. ] 



WATER-MILFOIL FAMILY. 



503 



i. Myriophyllum spicatum L. Spiked 

 Water-Milfoil. (Fig. 2617.) 



Myriophyllum spicatum L. Sp. PI. 992. 1753. 



Submerged leaves in whorls of 4's and 5's, dissected 

 into capillary divisions. Floral leaves ovate, entire or 

 serrate, usually shorter than the flowers, or sometimes 

 none; spike i f -$' long; petals 4, deciduous; stamens 8; 

 fruit about i" long and i l / 2 " thick; carpels rounded on 

 the back, with a deep wide groove between them, 

 smooth, or very rarely slightly rugose. 



In deep water, Newfoundland to Manitoba and the North- 

 west Territory, south to Florida, Iowa, Utah and California. 

 Also in Europe and Asia. 



_L 



2. Myriophyllum verticillatum L/. Whorled 



Water- Milfoil. (Fig. 2618.) 

 Myriophyllum verticillatum L. Sp. PI. 992. 1753. 



Submerged leaves in crowded whorls of 3's and 4's, the 

 capillary divisions very slender, sometimes finer than those 

 of M. spicatum , about 10 pairs, i f -i% f long, often mi- 

 nutely scabrate. Floral leaves pectinate or pectinate- 

 pinuatifid, much longer than the flowers; spike 2 / -6 / 

 long; petals of the staminate flowers 4, purplish; stamens 

 8; fruit \"-\W long, and about i" thick, somewhat 

 gibbous at the base. 



In both deep and shallow water, Quebec and Ontario to 

 Florida, west to Minnesota and California. Also in Europe 

 and Asia. 



3. Myriophyllum alterniflorum DC. Loose- flowered Water- Milfoil. 



(Fig. 2619.) 



Myriophyllum alterniflorum DC. Fl. France, Suppl. 529. 

 1815. 



Submerged leaves usually in whorls of 3-5, occasionally 

 scattered, the pinnate divisions capillary, 3 // -5 // long. 

 Spikes short, I'-a' long, numerous or several on the 

 branching stems; uppermost floral leaves ovate or linear, 

 entire or minutely toothed, smaller than the flowers, 

 early deciduous; petals of the staminate flowers 4, longer 

 than the stamens, pale rose-color, deciduous; stamens 8; 

 fruit nearly \" long, slightly less than \" thick; carpels 

 rounded on the back, with a deep groove between them. 



In deep water, Lake Memphremagog, Quebec, near the 

 United States boundary; Lake Temiscouata, Quebec; north 

 to Newfoundland and Greenland. Common in Europe. 



4. Myriophyllum tenellum Bigel. Slender 

 Water-Milfoil. (Fig. 2620.) 



Myriophyllum tenellum Bigel. Fl. Bost. Ed. 2, 346. 1824. 



Stems slender, scape-like, nearly leafless, simple, erect, 

 i%'-6 f or rarely 12' high. Rhizome creeping, sending 

 up many sterile stems; flowers alternate, solitary; upper- 

 most bracts obovate, often longer than the flowers, the 

 lower oblong, often shorter, the lowest minute or none; 

 petals 4, purplish, longer than the stamens; stamens 4; 

 fruit %" long and about as thick at the top, sometimes 

 enlarged at the base; carpels rounded or obtusely angled 

 on the back, separated by a shallow groove. 



Sandy bottoms of ponds and streams, Newfoundland to 

 New Jersey and Pennsylvania, west to Michigan. 



