644 



AMMIACEAE. 



VOL. II. 



Musineon Hookeri (Nutt.) T. & G. differs in being scabrous. It inhabits the Rocky Mountain 

 region, ranging eastward into South Dakota and western Nebraska. 



2. Musineon tenuifolium Nutt. 

 Fig- 3 I 44- 



Scapose Musineon. 



Musenium tenuifolium Nutt. ; T. & G. Fl. N. A. i : 642. 1840. 

 Adorium tenuifolium Kuntze, Rev. Gen. PI. 264. 1891. 



Acaulescent from a woody root, tufted, glabrous, 2'-6' 

 high, pale and somewhat glaucous. Leaves petioled, decom- 

 pound into linear acute incised segments ; scape equalling or 

 slightly exceeding the leaves; umbel i'-i' broad, 5-i8-rayed; 

 rays 2"-s" long; flowers greenish white (?); pedicels \"-2." 

 long in fruit ; fruit oblong, nearly smooth, about i" long and 

 \" thick, its ribs rather prominent when dry. 



In dry rocky places. South Dakota, Nebraska, and in the Rocky 

 Mountains. June-July. 



29. CYMOPTERUS Raf. Journ. Phys. 89: 100. 1819. 



Perennial subscapose glabrous herbs, with thick roots', pinnately decompound leaves, 

 and white flowers (in our species) in peduncled umbels. Involucre of several bracts or none. 

 Involucels of i to numerous bracts. Calyx-teeth rather prominent. Petals inflexed at the 

 apex. Stylopodium depressed. Fruit globose, ovoid or ellipsoid, flattened laterally or not 

 at all. Carpels dorsally flattened, with 3-5 flat equal wings ; oil-tubes several or solitary in 

 the intervals, few or several on the commissural side. [Greek, wave-winged, referring to 

 the fruit.] 



About 13 species, natives of western and central North America, the following typical. 



Plains Cymopterus. Fig. 3145. 



i. Cymopterus acaulis (Pursh) Rydberg. 



Selinum acaule Pursh, Fl. Am. Sept. 732. 1814. 

 Cymopterus glomeratus Raf. Journ. Phys. 89: TOO. 1819. 



Cymopterus acaulis Rydberg, Bot. Surv. Neb. 3 : 38. 

 1894. 



Low, the stem seldom over i' high. Leaves erect 

 or ascending, bright green, 3'-8' long, slender- 

 petioled, pinnate or bipinnate into linear-oblong 

 obtuse entire or lobed segments; umbels slender- 

 peduncled, compact, i' or less broad, several-rayed; 

 rays only i"-2*" long; pedicels very short; involucre 

 none; involucel of a single palmately-lobed bractlet; 

 fruit broadly oval, about 3" in diameter when 

 mature ; oil-tubes 4-5 in the intervals ; seed-face 

 nearly flat. 



In dry soil, Minnesota, Wisconsin and Iowa to Arkan- 

 sas, Assiniboia, British Columbia and Colorado. April- 

 May. 



30. PHELLOPTERUS Nutt. ; Coult. & Rose, Contr. U. S. Nat. Herb. 7 : 166. 



1900. 



Perennial, nearly or quite acaulescent herbs, with j-3-pinnate leaves, their segments 

 small, short and broad, the flowers white or purple. Calyx-teeth distinct. Fruit glabrous, 

 ovate to orbicular, each carpel with 3-5 broad thin wings. Stylopodium none. Oil-tubes 

 2 or 3 in each interval, 4-8 on the commissural side. [Greek, referring to the broad wings 

 of the fruit.] 



About 5 species, natives of the central and western United States, the following typical. 



