588 
MONOECIA TRIANDRIA. 
1. Verticillatum. Lin. 
M. foliis pinnatis, 
capillaceis, superiori- 
bus pectinato-pinnatifi- 
dis; floribus axillaribus, 
verticiliatis, superiori- 
bus masculis, 8-andris. 
Leaves pinnate, ca- 
pillary, the upper pec- 
tinate, pinnatifid; flow- 
ers axillary, verticil- 
late, the upper sterile 
octandrous. 
Sp. pi. 4. p. 407. Mich. 2. p. 490. Pursh, 1. p. 274. Nutt. 2. p. 211. 
The upper florets of this species sometimes produce both styles and sta- 
mens. 
Grows from Canada to Carolina; and in Lower Louisiana, Nutt, 
Flowers July— August. Pursh. 
2. Scabratum. Mich. 
M. foliis pinnatifidis; 
floribus omnibus verti- 
ciliatis axillaribus; su- 
perioribus masculis 4- 
andris, inferioribus fo- 
emineis; fructu 8-an- 
gulato. 
Leaves pinnatifid; 
flowers verticillate ax- 
illary; the upper sterile 
tetrandrous, the lower 
fertile; fruit 8-angled. 
Mich. 2. p. 190. Sp. pi. 4. p. 408. Pursh, 1. p. 274. Nutt. 2. p. 211. 
Potamogeton Pinnatum, Walt. p. 90. 
Roo£ perennial. Stem about 12 inches high, terete, procumbent and 
assurgent, floating, taking root at the lower joints. Leaves verticillate, gen- 
erally by fours, the lowest setaceous resembling fibres, the upper linear, pin- 
natifid, rarely an inch long, with 2 segments usually on each side. Flowers 
verticillate, also by fours, sessile, small; the upper sterile. Corolla of both 
florets pale purple. Stamens 6 , scarcely longer than the corolla. Fruit 
as if composed of 4 seed united each having an elevated broad 2-edged rib 
along the back. 
Grows in shallow ponds. 
Flowers April — June, and probably through the whole summer. 
3. Heterophyllum. Mich. 
M. foliis inferioribus Lower leaves capil- 
eapillaceo pinnatis, su- lary, pinnate, the up- 
