710 



50 



Map 1499 



Circaea alpina L. 



2. Circaea alpina L. Map 1499. Very local but often common where 

 found. In bogs and on old logs in swamps and in very damp places such 

 as deep ravines. 



S. Lab. to James Bay and Alaska, southw. to N. E., Ga., the Great Lakes 

 and S. Dak. ; found also in Eurasia. 



225. HALORAGIDACEAE Klotsch & Garcke. Water-milfoil Family 



Leaves in whorls (sometimes scattered in Myriophyllum scabratum) . 



Plants with immersed leaves dissected; emersed leaves not entire; stamens 4 or 8; 

 fruit 4-celled 5834. Myriophyllum, p. 710. 



Plants with all the leaves entire; stamen 1; fruit 1-celled 5837. Hippuris, p. 712. 



Leaves alternate; fruit 3-angled 5835. Proserpinaca, p. 711. 



5834. MYRIOPHYLLUM [Vaill.] L. Water-milfoil 



Bracts or floral leaves entire, sparingly dentate or serrate. 



Bracts shorter than or rarely as long as the flowers or fruit, ovate to very broadly 



ovate, entire with a narrow, brown, chartaceous margin or sparingly dentate; 



stamens 8; carpels 2-3 mm long, smooth; rachis of leaf about the width of the 



divisions 1. M. exalbescens. 



Bracts about twice as long as the flowers or fruit or even longer, linear-oblong, finely 



serrate; stamens 4; carpels 1-1.5 mm long, papillose, 2-ridged on the back; 



stigmas prominent; rachis of leaf slightly broader than the divisions 



2. M. heterophyllum. 



Bracts pectinate. 



Bracts about 5 times as long as the flowers or fruit; stamens 4; fruit 1-1.5 mm long, 



with 2 ridges on the dorsal side, the lateral faces slightly roughened; divisions 



of the leaf mostly wider than the rachis 3. M. scabratum. 



Bracts as long as or up to 2.5 times as long as the flowers or fruit; stamens 8; 



carpels 2.5-3 mm long, smooth; stigmas prominently recurved; rachis of leaf 



slightly broader than the divisions 4. M. verticillatum var. pectinatum. 



1. Myriophyllum exalbescens Fern. (Rhodora 21 : 120. 1919.) (Myrio- 

 phyllum spicatum L. of Gray, Man., ed. 7 and Britton and Brown, Illus. 

 Flora, ed. 2.) Map 1500. This is our most common species of the genus 



