POLYGAMIA, FRUSTRANEA. 
13S 
Coreopsis alternifolia, L. and others. 
Verbesina Coreopsis, Mich, and Pursh. 
From three to seven feet high. Flowers not handsome, 
yellow. On the marshy shores of all our waters, abundant. 
Perennial. July, September. 
ORDER IV. POLYGAMIA NECESSARIA. 
(Bxidialjlorets only, fertile.') 
330. AMBROSIA. Gen.pl. 1427. {Corymbifera.) 
Monoicous. — M asc. Calix l-leaved. »3 r- 
thers approximate, but not united. Recep- 
tacle naked. — ^F em. Calix l-leaved, entire 
or 5-toothed, 1 -flowered. Corolla none. 
JSTut formed from the indurated calix, 1- 
seeded. — JSTutt. 
1 . A. hirsute, asperate j leaves 3 -Iobed, serrated ; tnfida. 
lobes oval-lanceolate, acuminate ; fruit 6-spined 
below the top. — Willd. and Pursh. 
Icon. Morris. HLst. 3 . s. 6. t. 1. f. 4 . 
Trif d-leaved Hogweed. 
From four to eight feet high. Flowers very ordinary and 
small. On the banks of rivers, creeks and ditches, every where 
very common. Annual. August, September. 
2. A. leaves bi-pinnatifid, hairy beneath, upper artemisifoiia. 
ones pinnatifid ; racemes ternate, terminal 5 
branches fastigiate. — iVilld. 
JVormwood-leaved Hogweed. 
From two to four feet high. A very common weed in all 
cultivated grounds and neglected fields. Annual. August, 
September. 
