352 UMBELLIFERAE (PARSNIP FAMILY) 



2 on the commissural side and a small one in each rib. Seed sulcate beneath 

 the oil-tubes, with face plane or slightly concave. 



Peduncles longer than the leaves 



Leaflets rhombic, deeply cut into lanceolate lobes . . . . . 1. A. acaulis. 



Leaflets broadly obovate, more or less cleft ... . . 2. A. obovata. 



Peduncles much shorter than the leaves 3. A. humilis. 



1. Aletes acaulis (Torr.) C. & R. Contrib. U. S. Nat. Herb. 7: 106. 1900. 

 Caespitose, with peduncles 10-30 cm. high, often much longer than the leaves: 

 leaflets rhombic, deeply cut into lanceolate acuminate lobes: umbels 8-15- 

 rayed; rays stiff, 19-20 mm. long: fruit almost sessile, narrowly oblong, 

 4 mm. long. *Carum Hallii. Rocky foothills of Colorado and New Mexico. 



2. Aletes obovata Rydb. Bull. Torr. Bot. Club 31: 573. 1904. Caespitose, 

 with peduncles 10-30 cm. high: leaflets broadly obovate, 1-2 cm. long, more 

 or less cleft, with short ovate teeth, strongly veined beneath: fruiting rays 

 2-2.5 cm. long; pedicels very short or none: fruit 5-6 mm. long. Colorado. 



3. Aletes humilis C. & R. 1. c. 107. Caespitose, with peduncles much shorter 

 than the leaves, 2-5 cm. long: petioles slender, longer than the blade; leaflets 

 generally 5, entire to few-toothed, slightly scabrous on the margin, linear to 

 obovate: rays 4-6, rather weak and spreading, 2.5-3 cm. long; pedicels very 

 short; involucels of linear, distinct bractlets: fruit ovate, 3 mm. long. Type 

 locality only; Dale Creek, Colorado, near the Wyoming line. 



11. SIUM L. 



Smooth perennials growing in water or wet places, with pinnate leaves and 

 serrate or pinnatifid leaflets, involucre and involucels of numerous narrow 

 bracts, and white flowers. Calyx-teeth minute. Fruit flattened laterally, 

 ovate to oblong, glabrous. Carpel with prominent, corky, nearly equal ribs, 

 each with a prominent group of strengthening cells at tip; stylopodium de- 

 pressed ; styles short ; oil-tubes 1-3 in the intervals (never solitary in all the 

 intervals), 2-6 on the commissural side. Seed subangular, with plane face. 



1. Sium cicutaefolium Gmelin, Syst. 2: 482. 1791. Stout. 6-8 dm. high; 

 leaflets 3-8 pairs, linear to 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. Throughput our 

 range and across the northern half of the United States. 



12. BERULA Hoffm. 



Smooth aquatic perennial, with simply pinnate leaves and variously cut 

 leaflets, usually conspicuous involucre and involucels of narrow bractlets, and 

 white flowers. Calyx- teeth minute. Fruit flattened laterally, nearly round, 

 emarginate at base, glabrous. Carpel nearly globose, with very slender, in- 

 conspicuous ribs, thick corky pericarp, and no strengthening cells; stylo- 

 podium conical; oil-tubes numerous and contiguous, closely surrounding the 

 seed cavity. Seed terete. 



1. Berula erecta (Huds.) Coville, Contrib. Nat. Herb. 4: 115. 1893. Erect, 

 1.5-9 dm. high or even smaller: leaflets 5-9 pairs, linear to oblong or ovate, 

 serrate to cut-toothed, often laciniately lobed, sometimes crenate, 1-7.5 cm. 

 long: umbel many-rayed; rays 5 cm. long or less; pedicels 4-6 mm. long: fruit 

 scarcely 2 mm. long. Very widely distributed. 



13. LIGUSTICUM L. 



Smooth perennials from large aromatic roots, with usually large, ternately 

 or pinnately compound leaves mostly no involucre, usually involucels of nar- 

 row bractlets, and white or pinkish flowers in large, many-rayed umbels. 



