262 AMMIACEAE. 



13. CARUM L, 



Smooth erect slender herbs with tuberous or fusiform 

 fascicled roots, pinnate leaves with few linear leaflets, 

 and white flowers. Calyx-teeth prominent for the size 

 of the fruit. Fruit flattened laterally, orbicular to 

 oblong, glabrous. Carpel with filiform or inconspicuous 

 ribs. Stylopodium conic. Oil-tubes large and solitary 

 in the intervals, 2-6 on the commissural side. Seed 

 dorsally flattened, more or less sulcate beneath the 

 tubes, the face plane or slightly concave. 



1. C. gairdneri (H. & A.) Gray. Stem 3-12 dm. high from 

 fascicled tuberous or fusiform roots; leaves few, usually simply 

 pinnate, with 3-7 linear-filiform leaflets, 5-15 cm. long; umbels 

 6-15-rayed; bracts several or none; bractlets linear, acuminate; 

 rays 2.5-4 cm. long; fruit broadly ovate or nearly orbicular, 1-2 

 mm. long, with small ovate calyx-teeth, low conic stylopodium and 

 long slender styles; seed terete. 



Occasional along borders of marshes. 



2. C. lemmoni C. & R. Resembling the last, but fruit oblong, 

 tapering somewhat at base and apex, 3 mm. long and 2 mm. broad, 

 with conspicuous ribs, each of which contains a small group of 

 strengthening cells; calyx-teeth prominent, concealing the stylo- 

 podium; styles long and slender. 



Occasional in marshes toward the coast. 



14. SIUM L. 



Smooth perennials growing in water or wet places, 

 with pinnate leaves, serrate or pinnatifid leaflets, involu- 

 cres and involucels of numerous narrow bracts, and 

 white flowers. Calyx-teeth minute. Fruit flattened 

 laterally, ovate to oblong, glabrous. Carpel with promi- 

 nent corky nearly equal ribs. Stylopodium depressed; 

 styles short. Oil-tubes 1-3 in the intervals. Seed sub- 

 angular, with plane face. 



1. S. cicutaefolium Gmel. Stout, 6-8 dm. high; leaflets 3-8 

 pairs, linear-lanceolate, sharply serrate and mostly acuminate, 

 5-13 cm. long, lower leaves sometimes submersed and finely dissected; 

 umbel many-rayed; rays 2.5-4 cm. long; pedicels 2-6 mm. long; fruit 

 3 mm. long, with prominent ribs; oil-tubes 2-6 on the commissural 

 side. 



Oak Knoll, McClatchie. 



2. S. heterophyllum Greene. Stems stout, angular and flexuose, 

 1 m. high; lowest leaves with a single lamina which is rather broadly 

 rhombic-lanceolate, serrate or laciniate-cleft, 5-20 cm. long; petiole 

 stout, fistulose; the other leaves 3-lobed or divided and passing to 



