This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
[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.
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.
Musineon Hóokeri (Nutt.) T. & G. differs in being scabrous. It inhabits the Rocky Mountain region, ranging eastward into South Dakota and western Nebraska.
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.