COULTER AND ROSE—NORTH AMERICAN UMBELLIFERAE. 71 
with 4 filiform secondary ribs and thin very hard pericarp. Stylopo- 
dium conical, with styles recurved over the carpels. Oil tubes none. 
Seed face deeply concave. 
Slender smooth annuals, with leaves pinnately dissected into filiform 
seements, involucre and involucels 
of few small bracts, and white 
flowers in few-rayed umbels. 
Type species, 2. dicocca Hottn. 
l. c., of Europe and the Orient. 
A group of 5 species, 4 of 
which are distributed throughout 
Europ ‘and Asia, and a single one 
in North America, almost entirely 
restricted to the dry plains of Texas. 
Fic, 9.—Bifora americana: a, b, x 6. 
1. Bifora americana (DC.) Watson, Bibl. Index 415. 1878. Fig. 9. 
Atrema americana DC, Coll. Mém,. 5: 71. pl. 18, 1829. 
Anidrum americanum Kuntze, Rev. Gen. Pl. 1: 264. 1891. 
Stems 3 dm. or more high, branching above; umbels 5 to 8-rayed; 
rays 12 to 18 mm. long; pedicels about 2 mm. long; fruit 3 mm. long, 
5 mm. broad. 
Type locality, ‘‘prés de la riviére Rouge;” collected by Nuttall, 
type in Herb. DC., duplicate in Herb. Philad. Acad. 
Dry ground, throughout Texas, and extending into the borders of 
Indian Territory and probably Arkansas. 
Specimens examined: 
Texas: Lindheimer 405, in 1846-1848; Nueces region, Wright 1108, in 1851; Bur- 
ton, [all 262, Moy? 25, 1872; near Dallas, Reverchon 374, May, 1879; Gillespie 
County, Jermy 139; near San Sabin, Nealley 156, July, 1890; Brazos County, 
Dewey, June 9, 1891; Kerr County, /eller 1656, May 14-21, 1894; Industry, 
Wurzlow, May, 1 895. 
InpiAN Terrirory: Near Caddo, Sheldon 41, June 20, 1891. 
For introduced species see page 252. 
10. APIASTRUM Nutt. in Torr. & Gray, Fl. 1: 648. 1840. 
Calyx teeth obsolete. Fruit ovate or cordate, with obscure or obso- 
lete ribs, more or less tuberculate. Car- 
pel with thin pericarp and no strength- 
ening cells. Stylopodium minute and 
depressed, with short style. Oil tubes soli- 
tary in the intervals and beneath the ribs, 
2 on the commissural side. Seed face nar- 
rowly concave or sulcate. . Fic, 10.—Apiastrum patens: 
Very slender smooth branching (some- OX 10; 0, 12, 
what dichotomously annuals), with finely dissected leaves having fili- 
