UMBELLIFERJE. 143 



HAB. Wet grounds. Can. to Car. W. to Miss. July, Aug. 

 If. Stem 3 4 feet high, terete, smooth. Petals white, obcor- 

 date. Poisonous and medicinal. Big. Med. Bot. i. 125. 



Water Hemlock. 



2. C. bulbi/era Linn. : leaves various, ternate and biternate ; leafet* 

 linear and linear-lanceolate, remotely toothed ; umbels small, termi- 

 nal, solitary ; partial involucre of 3 5 subulate leaves ; axils of the 

 leaves bulbiferous. 



HAB. Swamps. Can. and N. S. Aug. U-Stem 23 feet 

 high, smooth and slender. Umbels small. Flowers white. 



7. ZIZIA. Koch. DC Cand. 



Calyx with the margin obsolete or very short, 5-toothed. 

 Petals elliptic, attenuated into a long inflexed point. Fruit 

 laterally contracted, subdidymous, roundish or oval. Carpels 

 with 5 prominent equal ribs ; the lateral ribs margined.- Ge- 

 neral involucre none ; partial one few-leaved. Flowers yel- 

 low, rarely white or dark purple. Pentandria. Dlgynia. 



1. Z.aureaKoch: leaves biternate, shining; segments oblong-lan- 

 ceolate, attenuate at base, incisely serrate ; partial involucre 3-leaved, 

 unilateral Smyrnium aureum Linn. Sison aureus Spreng. Torr. 

 Tkaspium aureum Nutt. 



HAB. Rocky hills. N. Y. to Car. W. to Miss. June, July. 

 If.. Stem 1 1-2 to 2 feet high. Rays of the umbel short. Flow- 

 ers bright yellow. 



2. Z. cordata Koch : radical leaves undivided, cordate, crenate, pe- 

 tiolate ; cauline ones subsessile, ternate ; segments petiolate, ovate, 

 cordate, serrate ; partial involucre 1-leaved. Smyrnium cordat um Walt. 

 S. trifoliatum Nutt. 



HAB. Meadows. Can. to Flor. W. to Miss. May, June. If.- 

 Stem 12 18 inches high, smooth. Floicers yellow. Fruit black. 



3. Z. integerrima De Cand. : leaves biternate, somewhat glaucous ; 

 segments ovate, very entire ; partial involucre 1-leaved, very short. 

 Smyrnium inte gerrimum Linn. Sison inte gerrimus Spreng. Torr. 



HAB. Mountains. Can. to Geor. W. to Miss. June. If. 

 Stem 1 2 feet high. Umbel with elongated filiform rays. Flmo- 

 ers yellow. 



8. DISCOPLEURA. De Cand. 



Calyx with 5 subulate persistent teeth. Petals ovate, en- 

 tire. Fruit ovate, subdidymous. Carpels with 5 ribs; 3 

 dorsal ribs filiform, exsert, subacute ; 2 lateral ones with a 

 thick margin Leaves much divided ; the segments linear. 

 Partial involucre a few linear setaceous leafets. Flowers 

 white. Pentandria. Digynia. 



