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..
Perennial herbs, with alternate lobed or pinnatifid leaves and terminal, cymose or solitary, large and showy flowers. Calyx-tube mostly obconic, the limb 5-lobed. Petals 5, in some species apparently 10, where the outer staminodes are petaloid. Stamens very numerous. Ovary I-celled; styles 3. Capsule dehiscent at the summit, the placentae with horizontal lamellae between the 2-rowed seeds which are flat and more or less winged. [In honor of Thomas Nuttall, 1786-1859, American botanist.]
About 20 species, natives of western North America and Mexico. Type species: Bartonia decapetala Pursh.
Flowers about 2' broad; calyx-tube bractless.
Bracts at base of calyx linear, entire.
Bracts at base of calyx lanceolate, pinnatifid.
Flowers about 4' broad; calyx-tube bearing bracts.
Bartonia nuda Pursh, Fl. Am. Sept. 328. 1814.
Mentzelia nuda T. & G. Fl. N. A. 1: 535. 1840.
Nuttallia nuda Greene, Leaflets 1: 210. 1906.
Rough with minute pubescence, slender, 1°-5° high, often widely branched, the stems light-colored. Leaves all sessile, lanceolate or oblong-lanceolate, acute at the apex, usually sharply and deeply dentate, or the upper pinnatifid, 1'-4' long; flowers yellowish white, 1 1/2'-2' broad, opening in the evening; petals 10, about twice as long as the lanceolate calyx-lobes; calyx-tube not bracteolate, but 1 or 2 linear, mostly entire bracts at its base; stamens 100 or more, the outer ones somewhat petaloid; capsule oblong, 9'-12" long, about 3" thick; seeds numerous, wing-margined.
Plains, western Nebraska to Colorado and Wyoming. July-Aug.
Hesperaster strictus Osterhout, Bull. Torr. Club 29: 174. 1902.
Touterea stricta Osterhout; Rydb. Bull. Torr. Club 30: 276. 1903.
Nuttallia stricta Greene, Leaflets 1: 210. 1906.
Similar to the preceding species, but strict and less branched, 30 high or less, the stem white and rough-pubescent. Leaves lanceolate to oblong-lanceolate, obtuse or acute, sinuate-dentate, 3 1/2' long or less, not so deeply toothed as those of N. nuda; flowers several, corymbose, yellowish white, about 2' broad; stamens numerous, many of the outer filaments petaloid; calyx-tube not bracteolate, but subtended by lanceolate deeply pinnatifid bracts; capsule l'-l 1/2' long; seeds numerous, about 2" long, wing-margined.
Plains and hills, South Dakota to Wyoming, Nebraska, Colorado and Texas. June-Aug.
Bartonia decapetala Pursh, in Bot. Mag. pl. 1487. 1812. Bartonia ornata Pursh, Fl. Am. Sept. 327. 1814. Mentzelia ornata T. & G. Fl. N. A. 1: 534. 1840. Mentzelia decapetala Urban & Gilg, in Engl. & Prantl, Nat. Pfl. Fam. 3: Abt. 6a, 111. 1894. N. decapetala Greene, Leaflets 1: 210. 1906.
Roughish-pubescent, stout, seldom over 2° high. Leaves oval, lanceolate or oblong, acute or acuminate at the apex, sinuate-pinnatind, 2'-6' long, the upper sessile, the lower petioled; flowers mostly solitary and terminal, yellowish white, 3'-5' broad, opening in the evening; petals about twice as long as the lanceolate calyx-lobes; calyx-tube usually bracted; filaments all filiform, very numerous (200-300); capsule oblong, 1 1/2'-2' long, 5"-6" thick; seeds numerous, margined, not winged.
Plains, Iowa to North Dakota, Saskatchewan, Montana, Nebraska and Texas. Gunebo-lily. June-Sept.
Nuttallia laevica¨lis (Dougl.) Greene [Mentzelia laevicaulis (Dougl.) T. & G.] reported from Nebraska, and admitted into our first edition, is not definitely known within our area.