COULTER AND ROSE—NORTH AMERICAN UMBELLIFERAE, 43 
LEAVES not parallel-veined, variable in form and texture. 
BASAL LEAVEs not at all spiny-toothed. 
Plants low and slender, mostly prostrate, with small thin leaves. 
Bractlets longer than flowers; fruit strongly tuberculate -..-. 4. E. baldwinii. 
Bractlets shorter than flowers; fruit not strongly tubercu- 
late 2.222222 eee ee eee eee eee eee eee 5. FE. prostratum. 
Plants erect and mostly tall; leaves thick; eastern (except J. phyteumae). 
Leaves elongated, the petioles long and fistulous. 
Bractlets entire. 
Heads oblong, with a terminal tuft of conspicuous bractlets. 
6. FE. phyteumae. 
Heads globose, without conspicuous terminal bractlets.. 7. E. floridanum. 
Bractlets 3-toothed. 
Bractlets with unequal teeth (middle one largest) .....-. 8. E. aquaticum., 
Bractlets with equal teeth. 
Slender, 4.5 to 9 dm. high ............-------------- .. 9. EL ravenelli. 
Stout and taller (12 to 18 dm.)........2222---2-22.--- 10. FE. mettaueri. 
Leaves small, with short petioles. 
Upper leaves simple; bractlets tricuspidate.......-.--- 11. £2. integrifolium. 
Upper leaves palmately parted; bractlets entire.........--- 12. £. hookeri. 
3ASAL LEAVES spiny-toothed (sometimes reduced to nodose petioles). 
Southern and southwestern species. 
Heads small (12 mm. or less); sepals entire. 
Bractlets 3-toothed........---2.--------- eee ee eee ee eee 13. FE. aromaticum. 
Bractlets entire. 
Stems low and diffusely branching; bracts less conspicuous, green within. 
14. E. diffusum. 
Stem erect, less branching; bracts very conspicuous, not green within. 
Bracts linear-lanceolate; Jower leaves pectinate-dentate or with trian- 
gular bristly teeth. .........-...------ Decne eee eens 15. FE. wrightii. 
Bracts broadly cuneate; lower leaves not pectinate-dentate. 
16. dé. lemmoni. 
Heads large (25 to 35 mm. long); sepals 3 to 5-cuspidate.. 17. E. leavenworthit. 
Pacific slope species. 
Styles shorter than sepals. 
Bracts and bractlets entire.......-...-..---------------- 18. EF. armatum. 
Bracts and bractlets not entire. 
Bractlets little longer than the usually blue heads.... 19. /. articulatum. 
Bractlets twice as long as the heads, which are never 
blue ...2.. 2.00222 eee eee ee ee eee eee ee 20. E. petiolatum. 
Styles Jonger than sepals. 
Bractlets but little longer than flowers. 
Bracts weak and reflexed .........-.--2--2--000------- 21. EH. elongatum. 
Bracts rigid and not reflexed. 
3racts much longer than the heads...-.....----------- 22. E. jepsoni. 
Bracts little, if at all, longer than the heads. , . 
Heads small (about 6 mm.) .......-.----.-------- 23. HE. minimum. 
Heads larger (9 to10 mm.).........-..--...-. 24. FE. alismaefolium. 
Bractlets much longer than the flowers. 
Bracts narrowly lanceolate and spreading, entire...... 25. HE. longistylum. 
Bracts very narrow and rigid, more or less spinose-bristly. 
Bracts with conspicuous scarious margin at base. 
Erect and tall; bracts 18 to 20 mm. long....... 26. FE. oblanceolatum. 
Prostrate; bracts about 10 mm. long........--.-- 27. E. aristulatum. 
