Vor. II.J WATER-MILFOIL FAMILY. 503 
1. Myriophyllum spicatum L. Spiked 
Water-Milfoil. (Fig. 2617.) 
Myriophyllum spicatum L. Sp. Pl. 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 1/-3’ long; petals 4, deciduous; stamens 8; 
fruit about 1’ long and 1%4’’ thick; carpels rounded on 
the back, with a deep wide groove between them, / SSN 
smooth, or very rarely slightly rugose. y 
In deep water, Newfoundland to Manitoba and the North- 
west Territory, south to Florida, lowa, Utah and California. 
Also in Europe and Asia. 
g \ 
2. Myriophyllum verticillatum I, Whorled 
Water-Milfoil. (Fig. 2618.) 
Myriophyllum verticillatum V,. Sp. Pl. 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, 1/-114’ long, often mi- 
nutely scabrate. Floral leaves pectinate or pectinate- 
pinnatifid, much longer than the flowers; spike 2/-6/ 
long; petals of the staminate flowers 4, purplish; stamens 
8; fruit 1/’-1%’” long, and about 1/’ 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.) 
Seencr Divers alternifiorum 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, 1/-2’ 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 1/’ long, slightly less than 1/’ 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 tenéllum Bigel. Slender 
Water-Milfoil. (Fig. 2620.) 
Myriophyllum tenellum Bigel. F1. Bost. Ed. 2, 346. 1824. 
Stems slender, scape-like, nearly leafless, simple, erect, 
14/-6/ 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 44’’ 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. 
