606 UMBELLIFERjE. Helosciadium. 



opposite, furnished with several salient teeth : upper ones with the lateral 

 segments approximated to the stem. Peduncles usually longer than the 

 leaves. Heads about the size of a pepper-corn, when old somewhat cylin- 

 drical-ovate : involucre variable in length ; in /?. often several times longer 

 than the head. Flowers blue. Calyx-tube vesicular-papillose. — Allied to 

 E. Cervantesii, Laroche. 



E.foetidvm (Linn. excl. syn. Pluk.) is not a native of the United States. 

 Strebanthus, Raf. ! (in Seringe, bulletin,) is founded on Eryngium Baldwinii, 

 and is incorrectly described, as the parts of the flower are not quaternary. 



Tribe III. AMMINE^. Koch. 



Fruit evidently compressed laterally, and usually somewhat didy- 

 mous. Carpels with 5 equal filiform and sometimes slightly winged 

 primary ribs ; the lateral ones marginal : secondary ribs none. 

 Vittce various. Seed gibbously convex on the back, and flattish on 

 the face, or terete. — Umbels perfectly compound. 



6. AMMI. Tourn. ; Koch, Umb. p. 122 ; DC. prodr. 4. p. 112. 



Margin of the calyx obsolete. Petals obovate, with an inflexed point, 

 emarginate, or with 2 unequal lobes ; the exterior ones frequently larger. 

 Fruit laterally compressed, ovate-oblong. Carpels with 5 filiform equal ribs ; 

 the lateral ones marginal. Intervals with single vittae. Commissure with 2 

 vittse. Carpophore free, 2-parted. Seed terete-convex, flattish on the face. 

 — Herbs, with a fusiform root, and pinnately divided or many-parted leaves. 

 Umbels compound, many-rayed. Involucre many -leaved; the leaflets 3- 

 cleft or pinnatitid. Involucels many-leaved ; the leaflets undivided. 



1. A. majus (Linn.) : stem glabrous; leaves pinnately divided ; segments 

 cartilaginous on the margin, acutely serrate ; lower ones lanceolate ; the 

 upper ones many-cleft, linear. — DC. prodr. A. p. 112. 



Newfoundland, Pylaie, fide De Candolle. 



7. HELOSCIADIUM. Koch, Umb. p. 125; DC. mem. Umb. p. 21. 



Margin of the calyx obsolete or 5-toothed. Petals ovate, entire, with a 

 straight or inflexed point. Styles short. Fruit laterally compressed, ovate 

 or oblong. Carpels with 5 filiform slightly prominent ribs ; of which the 

 lateral ones are marginal. Intervals with single vittse. Carpophore entire, free. 

 Seed gibbously or teretely convex, flattish on the face. — Herbaceous. 

 Flowers white. 



§ 1. Aquatic, procumbent or creeping: leaves pinnately divided: involucre 

 1-3-leaved {rarely none) : involucels 5-6-leaved. — Mauchartia, Necker. 



1. H. nodiflorum (Koch) : stem procumbent, striate ; leaves pinnately di- 

 vided ; segments oblong, equally serrate ; umbels opposite the leaves, sessile 

 or on short peduncles ; involucre none, or few-leaved, deciduous. DC. 



