CLASS V. ORDER II. 121 



Syn. Thapsium aureum. Nutt. 

 ZiziA AUNEA. De Cand. 



About two feet high. General involucre none, partial involu- 

 cre of about three short lanceolate leafets on one side. Flowers 

 orange yellow, in umbels of moderate size. Fruit oval with 

 membranous ridges. — At Walpole, New Hampshire. — June. 



133. J2THUSA. 

 ^TiiusA CYNAPiuM. L. Fools Parsley. 



Leaves similar, bipinnate, leafets pinnatifid. 



This plant has at first sight considerable resemblance to Co- 

 nium maculatum, although smaller, and has been often gathered 

 by mistake for that plant by druggists. Stem about two feet 

 high, striated, not spotted. Leaves bipinnate and at length pin- 

 natifid. The distinguishing mark of this plant is in the partial 

 involucres which consist of only three leafets which are exter- 

 nal, linear, long and pendulous. — Common about the streets of 

 this city, probably introduced from Europe. — July, August. — 

 Annual. 



134. SISON. 



SisoN Canadense. L. HonetDort. 



Leaves ternate ; umbels irregular. 

 Syn. Chjekophylltjm Canadense. Pursh. 



Myrrhis Canadensis. Nutl. 



Crtptot^enia Canadensis. De Cand. 

 Stem smooth. Leaves in threes, the radical ones cleft, those 

 of the stem doubly toothed, rhomboidal, smooth or shining. Um- 

 bel branched, unequal, of few rays, with no general involucre. 

 Partial umbels unequal, close, few flowered, with a minute in- 

 volucre. Flowers small, white. Seeds smooth, oblong. — Chel- 

 sea beach island. — July. 



135. CICUTA. 

 CicuTA Maculata. L. American Hemlock. 



American Medical Botany, PI. xii. 



Root fascicled, leaves oblong, with mucronate ser- 

 ratures. 



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