SYNGENESIA. NECESSARtA. Anlbrosm. 
On the banks of ponds and ditches : Pensylvania and 
Virginia. 0 . July — Sept. v. v. The flowers of 
this genus are very inconspicuous. 
2 . A. hirsutissima folds arete sessilibus simplicibus oblon- 
gis supra basin latescentem utrinque unidentatis, truc- 
tu tetragono infra apicem quadrispinoso. Mich, fi, 
amer. 2 . p. 182. 
In the western parts of the Allegany mountains q. 
July— Sept. V. V. 
3. A. hirsuta, aspera 3 foliis 3 -lobis serratis, lobis ovali-lan- 
ceolatis acuminatis, fructu infra apicemO-spinoso.— 
IV aid. sp.pl. 4. p. 375. ^ 
Icon. Moris, hist. 3. 5 .. 6 . t. 1 ./. 4. 
On the banks of rivers and ditches : Pensylvania to Ca- 
rolina. Q. Aug. Sept. V. V. From five to eight 
feet high. 
4. A. foliis bipinnatifidis glabriuscnlis, petiolis longe cilia- 
tis, racemis terminalibus paniculatis, caiile virgato. 
Willd. sp. pi, 4. p. 376 . 
In old fields : Canada to Carolina. O* June— Aug, v.v. 
5. A. foliis bipinnatifidis subtus canescentibus summis pin- 
natifidis, racemis ternis terminalibuSj ramis fastigiatis. 
Willd. sp. pL 4. p. 37(5. 
In fields and waste grounds : Pensylvania to Carolina. 
O . Aug. Sept. V. V. 
6. A. foliis glabris bipinnatifidis summis pinnatifidis, race- 
mis terminalibus soliiariis, ramis fastigiatis. Willd. sp, 
pi 4. p, 376 . 
Icon. Pliik. aim. t. 10. f. 5. 
In old fields and on road sides : Canada to Florida. ©. 
July — Sept. V. V. 
7 . A. foliis caulinis piimatifidis subdeotatis petiolatis^ rameis 
summis ianceclatis sessilibus^ petiolis longe ciliatis, 
racemis terminalibus solitariis, cauie paniculato. 
fV illd. sp. pi, 4. p. 378 . 
On the banks of rivers and ditches : near Philadelphia. 
G. July— Sept. v.v. 
667. XANTHIUM. Gen. pi. 1426. 
I. X. cauie inermi ramoso, foliis cordatis lobatis serratis 
scabris basi trinervibus, fructibus ellipticis pubescent!- 
bus setis rigidis uncinatis.™ sp. pi. 4. p, 3/3. 
lidentaia, 
trijida. 
elatior. 
artemisifolm. 
pnniculata. 
heteropkylla* 
Strumarlum, 
