286 Umbelliferae 



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. Ijemmoni 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 stylopodium ; 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 acumi- 

 nate, 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 flexu- 

 ose, I'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 the truly pinnate, with 2 pairs of broadly 

 lanceolate, acute, serrate leaflets ; bracts broadly lanceolate, taper- 

 ing at both ends ; fruit 3 mm. long, strongly ribbed. 



Near Pasadena, Davidson. 



