208 



AMMIACEAE. 



Fruit with obscure or obsolete oil-tubes. 

 Fruit strongly flattened laterally. 



Fruit not strongly flattened laterally, sometimes turgid. 

 Seed-face concave. 

 Stylopodium conic. 



Fruit bristly-pubescent. 

 Fruit smooth and glabrous. 

 Stylopodium obsolete or flat. 



Fruits turgid, prominently ribbed : leaf -blades 



dissected. 

 Fruits of an oblong type, inconspicuously ribbed : 



leaf-blades entire, perfoliate. 

 Seed-face essentially flat. 

 Fruit with distinct oil-tubes. 



Fruit strongly flattened dorsally, the lateral ribs of the 



carpels more or less strongly winged. 

 Stylopodium conic. 



Fruit not notched at the apex, the carpels not very 



flat. 



Fruit notched at the apex, the carpels very flat. 

 Stylopodium obsolete or flat. 

 Corolla white. 

 Fruit spineless. 



Fruit armed with barbed spines. 

 Corolla yellow. 

 Fruit more or less flattened laterally, sometimes slightly 



dorsally flattened. 

 Oil-tubes solitary in the intervals. 

 Stylopodium conic. 



Leaf-segments, at least those of the upper 



leaves, narrowly linear or filiform. 

 Leaf-segments neither narrowly linear nor fili- 

 form. 



Seed-face concave or grooved. 

 Seed-face flat. 



Fruit short, often as wide as long. 

 Fruit elongate-oblong. 

 Stylopodium obsolete or flat. 

 Corolla white. 

 Corolla yellow. 



Fruit with winged ribs. 

 Fruit with merely filiform ribs. 

 Oil-tubes more than one on the intervals. 

 Stylopodium conic. 

 Stylopodium flat or obsolete. 

 Fruit without ribs, spiny. 

 Fruit ribbed, spineless. 

 Carpel-ribs filiform. 



Carpel-ribs corky, at least the lateral ones. 

 Oil-tubes continuous around the seed 



cavity : Stylopodium flat. 

 Oil-tubes 2-3 in the intervals : stylo- 

 podium obsolete. 



1. HYDROCOTYLE. 



5. WASHINGTONIA. 

 4. CEREFOLIUM. 



7. CONIUM. 



8. BUPLEURUM. 

 14. AEGOPODIUM. 



19. OXYPOLIS. 

 21. HERACLEUM. 



18. ANGELICA. 

 22. DADCUS. 

 20. PASTINACA. 



6. CORIANDRUM. 



3. CHAEROPHYLLUM. 



11. CICUTA. 



12. DERINGA. 



9. CELERI. 



17. THASPIUM. 

 10. ZIZIA. 



16. LlGUSTICUM. 



2. SANICULA. 



13. TAENIDIA. 



8. BUPLEURUM. 

 15. SIUM. 



1. HYDROCOTYLE [Tourn.] L. Perennial amphibious herbs. Leaves 

 solitary at each node. Umbels simple or proliferous. Sepals manifest. Petals 

 valvate. Carpels with distinct ribs, and oil-bearing tissues beneath the epi- 

 dermis. Sum. MARSH-PENNYWORT. WATER-PENNYWORT. 



Umbels nearly sessile : leaf-blades shallowly lobed. 1. H. americana. 



Umbels long-peduncled : leaf-blades deeply lobed. 2. H. ranunculoides. 



1. H. americana L. Leaf -blades reniform, 2-5 cm. wide, crenate-lobed : petals 

 less than 1 mm. long: fruits 11.5 mm. wide, sharply ribbed, oval in cross- 

 section. Common, in swamps. 



2. H. ranunculoides L. f. Leaf -blades reniform to orbicular-reniform, 2-5 cm. 

 wide, deeply lobed: petals over 1 mm. long: fruits 2.5-3 mm. wide, obscurely 

 ribbed, oblong in cross-section. Bare, in wet places, especially abundant in 

 the Susquehanna valley. 



2. SANICULA [Tourn.] L. Biennial or perennial, glabrous or nearly 

 glabrous herbs. Leaves alternate : blades pinnatifid or palmately 3-7-f oliolate : 



