COULTER AND ROSE—NORTH AMERICAN UMBELLIFERAE. 89 
strengthening cells. Styles very short. Oil tubes solitary in the inter- 
vals, 2 on the commissural side; all rather small and not close to the 
seed cavity. Seed dorsally flattened, with plane face. 
Low diffuse annuals, with ternately divided leaves, the small ulti- 
mate segments linear to spatulate,involucre and involucels of entire or 
dissected bracts, and white flowers in 
small sessile or short pedunculate 
unequal umbels. 
Type species, A. popet T. & G. 
A genus of two species, largely 
restricted to Texas, but extending 
into western Kansas, Arizona, and 
Mexico. 
Rough scabrous; fruit ovate-oblong, 4 to 4 
min, long. 
Fic, 21.—Ammoselinum popei: 
Low, 1 dm. high.........--- lL. ud. popel. : 
“MN oo. . . . Oy a, x8; b, x 10. 
Taller, 2 to 3.dm. high... 2. uf. giganteum. 
Nearly glabrous; fruit ovate, 2 mm. long .........-.----------------- 3. A. butleri. 
1. Ammoselinum popei Torr. & Gray, Pacif. R. Rep. 2°: 165. 1855. 
Fig. 21. 
Apium popei Gray, Proc. Am. Acad. 72 348. 1867. 
About 1 dm. high, with stem-angles, rays, pedicels, and ribs of fruit 
rough scabrous; leaf segments narrowly linear; fruit ovate-oblong, 
4to5 mm. long, with thick corky commissure. 
Type locality, ‘*sandy soil, Llano Estacado and head waters of the 
Colorado;” collected by Diffendorfer; type in Herb. Gray. 
In sandy soil, western Kansas to Texas, and extending into Mexico. 
Specimens examined: 
Kansas: Southwestern Kansas, Plank. 
Texas: Tom Green County, Tireedy 188, May, 1880; Brown County, Reverchon 
1402, April, 1882; San Diego, Mary B. Croft 81, in 1884; Nueces County, 
Heller 1474, March 21, 1894. 
2, Ammoselinum giganteum C. & R., sp. nov. 
Much branched throughout and spreading, the branches 2 to 3 dm. 
long, angled and roughened; fruit ovate, 5 mm. long, with rather thin 
commissure, densely and sharply scabrous. 
Type locality, mesas near Phoenix, Ariz.; collected by CL G. Pringle, 
no. 28, June 17, 1882; type in Herb. Gray. 
Only known from type locality. 
Specimens examined: 
ArIzoNA: Type specimens as cited under type locality. 
Here perhaps belong specimens collected in the desert around Maricopa, Ariz., by 
L. H. Dewey, in June, 1894, except that the fruit is narrowly oblong and smaller. 
The material is rather fragmentary and should be collected in quantity by collectors 
in that region. 
