216 CONTRIBUTION'S FROM THE NATIONAL HERBARIUM. 



Stem leaves compound or lobed, the basal leaves simple or compound. 

 Fruit (even when very young) covered with straight or hooked bristleB. 

 Flowers sessile or nearly so, yellowish or white; leaves digitately compound, 



of 3-7 leaflets. Fruit covered with hooked bristles 2. SANICTJLA. 



Flowers pediceled, white; leaves pinnately compound, usually with numerous 

 divisions. 

 Bracts at the base of the umbel large, divided into linear lobes. Fruit covered 



with barbed bristles; plants very hairy 3. DATJCTJS. 



Bracts at the base of the umbel small and entire or none. 

 Plants annual; fruit obtuse at the base, covered with hooked bristles. 



4. TORILIS. 

 Plants perennial; fruit very acute at the base, with straight bristles. 



__ . . . 5. OSMORRHIZA. 



Fruit not bristly, sometimes pubescent. 



Leaflets entire. Perennial; flowers yellow 13. TAENIDIA. 



Leaflets or leaves toothed or lobed. 

 Flowers yellow or purplish. Plants perennial. 

 Leaves pinnate, the leaflets sessile, several; fruit flattened; bractlets none 



at the base of the pedicels 8. PASTINACA. 



Leaves simple or ternately compound, the leaflets usually stalked, often 

 only 3; fruit not flattened; bractlets present at the base of the pedicels. 



Fruit winged ; leaves all divided 12. THASPITTM. 



Fruit not winged; leaves sometimes simple 14. ZIZIA. 



Flowers white. 



Leaves once pinnate, the leaflets linear or lanceolate, finely toothed, sessile. 

 Plants perennial. 

 Fruit winged; bracts at the base of the umbel 3 or fewer, filiform, some- 

 times wanting; pedicels 6-18 mm. long 11. OXYPOLIS. 



Fruit not winged; bracts at the base of the umbel 6 or more, conspicuous; 



pedicels 2-6 mm. long 18. SIu"M. 



Leaves not once pinnate with narrow-toothed leaflets, 2 or 3 times pinnate or 

 else 1-3 times ternate, the leaflets usually coarsely toothed or lobed, 

 usually stalked. 

 Bractlets none at the base of the pedicels. Leaves 3-parted; plants peren- 

 nial, glabrous 7. DERINGA. 



Bractlets present at the base of the pedicels. 

 Plants annual, low and slender. 

 Bracts none at the base of the umbel; plants sparsely pubescent. 



6. CHAEROPHYLLUM. 

 Bracts present at the base of the umbel, divided into linear lobeB; 



plants glabrous 19. PTILIMNIUM. 



Plants perennial, tall and stout, or in one species very low but with 

 tuberous roots. 

 Plants low and slender, usually less than 15 cm. high, flowering in 

 early spring; umbel with a leaf at the base; roots bulblike. 



16. ERIGENIA. 

 Plants tall and coarse, flowering in summer or autumn; umbel never 

 with a leaf at the base; roots not bulblike. 

 Branches of the umbel pubescent; fruit winged. 

 Leaflets usually 3, very hairy, deeply lobed; fruit winged on the 



margin 9. HERACLETTM. 



Leaflets more than 3, nearly or quite glabrous, shallowly toothed; 

 fruit winged on the back io. ANGELICA 



