Vor. II.] LOASA FAMILY. 459 
3. Mentzelia albicatlis Dougl. White-stemmed Mentzelia. (Fig. 2519.) 
Mentzelia albicaulis Dougl.; Hook. Fl. Bor. Am. 
I: 222. Assynonym. 1833. 
Bartonia albicaulis Dougl.; Hook. Fl. Bor. Am. 
I: 222. 1833. 
Stem nearly white, erect or ascending, slen- 
der, branched, shining, nearly smooth, or 
roughish above, 6/-2° high. Leaves sessile, 
mostly lanceolate in outline, sinuate-pinnatifid, 
sinuate-lobed, or the upper and lower some- 
times entire, rough with short stiff hairs, 1/—3/ 
long; flowers yellow, few together at the ends 
of the branches, or also axillary, 6’/—10’’ broad, 
short-pedicelled or sessile; calyx-lobes linear- 
lanceolate, about 2’’ long; capsule linear, 1/ 
long or less, many-seeded; seeds angled, 
tuberculate, wingless. 
Western Nebraska to British Columbia, Califor- 
nia and New Mexico, the more eastern plant with 
less pinnatifid leaves than the western, and perhaps 
different specifically. May-July. 
4. Mentzelia decapétala (Pursh) Urban 
& Gilg. Showy Mentzelia. (Fig. 2520.) 
Bartonia decapetala Pursh, in Bot. Mag. p/. 7487. 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. 
Roughish-pubescent, stout, seldom over 2° high. 
Leaves oval, lanceolate or oblong, acute or acumi- 
nate at the apex, sinuate-pinnatifid, 2/’-6’ long, 
the uppersessile, the lower petioled; flowers mostly 
solitary and terminal, yellowish white, 3/—5’ broad, 
opening in the evening; petals 10, about twice as 
long as the lanceolate calyx-lobes; calyx-tube usu- 
ally bracted; filaments all filiform, very numerous 
(200-300); capsule oblong, 1%/’-2’ long, 5//—-6// 
thick; seeds numerous, margined, not winged. 
Plains, Dakota and Montana to Nebraska and Texas. 
June-Sept. 
5. Mentzelia laevicaulis ( Doug]. ) 
T. & G. Smooth-stemmed Mentzelia. 
(Fig. 2521.) 
Bartonia laevicaulis Dougl.; Hook. Fl. Bor.Am. { (| 
I: 221. 1833. | 
Mentzelia laevicaulis T. & G. Fl. N. A. 1: 535. 1840. 
Stout, 2°-4° high, minutely pubescent, or the 
stems at length glabrate and whitish. Leaves 
sessile, lanceolate or ovate-lanceolate, sinuate- 
pinnatifid, acute or acuminate at the apex, 1/—3/ 
long; flowers mostly solitary and terminal, 
bright yellow, 3’—4/ broad, opening in sunshine; 
calyx-tube bractless; petals 5, or with 5 addi- 
tional narrower inner ones, 2-3 times as long 
as the calyx-lobes; stamens very numerous; 
capsule oblong, about 1/ long, 4’’ in diameter; 
seeds numerous, winged, minutely tuberculate. \ 
Plains and dry soil, Nebraska, Montana and 
Wyoming to Oregon, south to Utah and California. 
June-July. 
