[Adorium Raf. Neog. 3. 1825.]

[Musenium Nutt.; T. & G. Fl. N. A. 1: 642. 1840.]

Low perennial resiniferous herbs, branching or acaulescent, with pinnately decompound leaves, and compound umbels of yellow or white flowers1. Involucre none. Bracts of the involucels few, narrow. Calyx-teeth ovate. Petals clawed, the apex long and infolded. Stylopodium small, depressed. Fruit ovate or ovate-oblong, slightly compressed laterally, smooth or nearly so in our species (roughened in M. Hookeri). Carpels somewhat 5-angled, the ribs filiform, equal; oil-tubes usually 3 in the intervals, the middle one usually largest. Seed-face cancave. [A name of fennel.]

Four known species, natives of northwestern and central North America. Type species: Seseh divaricatum Pursh.

Stem leafy, branching; fruit about 2" long.

1.

M. divaricatum.

Plant acaulescent, tufted; fruit about 1" long.

2.

M. tenuifolium.

28 Mus neon Raf Journ Phys 91 71 1820 1485

1. Musineon Divaricàtum (Pursh) Nutt. Leafy Musineon

Fig. 3143

Seseli divaricatum Pursh, Fl. Amer. Sept. 732. 1814.

Musenium divaricatum Nutt.; T. & G. Fl. N. A. 1: 642. 1840.

Adorium divaricatum Rydberg, Bot. Surv. Neb. 3: 37. 1894.

Decumbent or ascending, branched, glabrous, 6'-12' high. Leaves bipinnatifid, petioled, 2'-6' long, the rachis narrowly winged, the segments oblong or ovate, acutish, 3-5-dentate; umbels mostly long-peduncled, 1'-2 1/2' broad., 8-25-rayed; rays rather stout, 3"-12" long; pedicels about 1 1/2" long in fruit; flowers yellow; fruit smooth, or very nearly so, about 2" long.

Prairies, South Dakota to Manitoba and Oregon. May-June.

Musineon Hóokeri (Nutt.) T. & G. differs in being scabrous. It inhabits the Rocky Mountain region, ranging eastward into South Dakota and western Nebraska.

1 Musineon Divaric Tum Pursh Nutt Leafy Musineon 1486

2. Musineon Tenuifólium Nutt. Scapose Musineon

Fig. 3144

Musenium tenuifolium Nutt.; T. & G. Fl. N. A. 1: 642. 1840. Adorium tenuifolium Kuntze, Rev. Gen. Pl. 264. 1891.

Acaulescent from a woody root, tufted, glabrous, 2'-6' high, pale and somewhat glaucous. Leaves petioled, decompound into linear acute incised segments; scape equalling or slightly exceeding the leaves; umbel 1/2'-1' broad, 5-18-rayed; rays 2"-5" long; flowers greenish white (?); pedicels 1/2"-2." long in fruit; fruit oblong, nearly smooth, about 1" long and \" thick, its ribs rather prominent when dry.

In dry rocky places, South Dakota, Nebraska, and in the Rocky Mountains. June-July.