OKDEB LXI. UMBELLIFEKJi. 329 



4 Flowers yellow or greenish 5 



Flowers wliitc or blue , 7 



5. Leaves i)innatcly divided Pdstinaca, I'J. Daiu:u.% 22 



Leaves leruately divided 6 



C, Seed nearly terete T/iaspiutn, 18 



Seed flat on one side, convex on tiic other Zifda, 12 



7. Seeds compressed 8 



Seeds scarcely compressed 13 



8. Seeds compressed on the sides 9 



Seeds compressed on the back 16 



9. Loaves 3-parted CryptotcBiiia, 1 1 



Leaves triternate or quinnate Cicuta, 8 



Leaves dissected, pinnate, or ternate 10 



10. Leaves bipinnate, segments pinnatifid Ch(Brophyllum, 23 



Leaves dissected, pinnate, or teruate 11 



11. Leaves much dissected 15 



Leaves pinnate or ternate 12 



12. Leaves ternate 13 



Leaves pinnate 14 



13. Involucre none Ilelosciadium, 5 



Involucre 2 — ^1-leaved Keurophyllum^ 10 



14. Involucre 1 — 3-leaved Helosciadium, 5 



Involucre 5 — 6-leaved Sium, 9 



15. Involucre with parted leaflets Discopleura, 6 



Involucre none Leptoca ulin, 7 



16. Leaves simple, terete Tiedma?inia, 17 



Leaves compound 17 



17. Petioles inflated, 3 -parted Archangelica, 16 



Petioles simple Archemora,, 18 



18. Seeds linear OHmorrhiza, 24 



Seeds ovate-oblong Lijusticum, 15 



Tribe L— HYDRO COT YLE'.E. 



J^'riiit laterally compressed. Seeds flat on the face. Vitice 

 2 or none. Umbels simple. 



Genus L— HYDROCOT'YLE. Touni. 5—2. 



(From the Greek hudor, water, and cottde, a cavity, from the locality of the plants 

 in the water, and the cup-like appearance the leaves sometimes assume.) 



Margin of the calyx obsolete. Petals entire, ovate, acute. 

 Fruit flattened laterally, 5-ribbed. Herbaceous plants, aquatic, 

 creeping stems and peltate or cordate leaves. Floivers in sim- 

 ple umbels. Involucre 4-leaved. 



1. H. America'na, (L.) Stem glabrous. Leaves orbicular, reniform, 

 slightly 7-lobed, crenate. Flowers few, sessile, in axillary umbels. — 

 "White or greenish. %. May — June. Mountains. 2 — 3 inches. 



2. H. intkrrup'ta, (Muhl.) Stem terete, glabrous, creeping, branch- 

 ing. Leaves peltate, orbicular, doubly crenate. Floivers in small, 

 nearly sessile, capitate umbels, 4 — 8-flowered. Fruit broad. — "White. 

 If. Through the summer. In M-^et soils. 3 — 4 inches. 



3. H. umbella'ta, (L.) Stem glabrous, creeping or floating.. L.eaves 

 peltate, crenate, eniarginate at the base. Umbels many-flowcrod, on 

 long peduncles. Fruit somewhat tumid. Calyx slightly toothed.— 

 White. U' Through the summer. Crows in bogs. 4—6 inchea. 



