284 



THE OENOTHERA FAMILY. 



V. MYRIOPHYLL. MYRIOPHYLLUM. 



Aquatic plants, with finely pinnated, whorled leaves, and minute, 

 sessile, monoecious flowers. Calyx with 4 short divisions. Petals 4 in 

 the male flowers, very minute or none in the females. Stamens in the 

 males 8, 6, or 4. Ovary and capsule of the females short, divided into 

 4 cells, with 1 seed in each. 



A small genus, widely diffused over almost every part of the globe. 

 In its finely-cut whorled leaves it bears at first sight much resemblance 

 to Ceratophyll, but the lobes of the leaves are pinnate, not repeatedly 

 forked as in the latter plant. 



Floral leaves or bracts not longer than the flowers ....]. Spiked M. 

 Floral leaves longer than the flowers, usually pinnate, like 



the stem-leaves 2. Whorled M. 



1. Spiked Myriophyll. Myriophyllum spicatum, Linn. 

 (Fig. 349.) 



(Eng. Bot. t. 83. Water Milfoil.) 



Hootstock perennial, creeping and 

 rooting in the mud under water. Stems 

 ascending to the surface, but usually 

 wholly immersed, varying in length ac- 

 cording to the depth of the water, and 

 more or less branched. Leaves whorled, 

 in fours or sometimes in threes or in 

 fives, along the whole length of the stem ; 

 the numerous capillary segments entire, 

 3 to near 6 lines long. From the sum- 

 mit of the branches a slender spike, 2 to 

 3 inches long, protrudes from the water, 

 bearing minute flowers arranged in little 

 whorls, and surrounded by small bracts 

 seldom as long as the flowers themselves. 

 The upper flowers are usually males, 

 their oblong anthers, on very short fila- 

 ments, protruding from the minute calyx 

 and petals. The lower ones are female, 

 very small, succeeded by small, nearly globular or slightly oblong 

 capsules, each separating ultimately into 4 one-seeded carpels. 



In watery ditches, and ponds, throughout Europe and Russian Asia. 

 Extending all over Britain. Fl. all summer. A starved slender va- 

 riety, with the whorls of the spike often reduced to a single flower, and 



Fig. 349. 



