534 LOASACEiE. Mentzelia. 



5. M. gracilenta : stem pubescent ; leaves lanceolate-linear, sessile, mu- 

 ricate-scabrous, jiinnatifid, the lobes short, obtuse, mostly entire ; bracteoles 

 at the base of the calyx pinnatifid ; flowers clustered at the summit of the 

 stem ; petals cuneiform-obovatc, obtuse or retuse, more than twice the length 

 of the ovate-lanceolate calyx-segments ; filaments numerous (40 or more), 

 tiUform-subulate ; ovary obconic ; ovules 20 or more. 



California, Douglas! — Since this plant is not noticed in Hooker & Arnott's 

 account of Douglas's collection, we are led to doubt whether it may not be 

 considered a slender variety of the preceding species ; but it is much smaller ; 

 the flowers not half the size ; the petals not at all pointed ; and the outline of 

 the leaves different. The filaments are dilated and somewhat united at the 

 base. 



6. M. albicaulis (Dougl. mss.) : low, branching from the base; stem 

 white and polished and nearly glabrous below ; leaves lanceolate, remote, 

 deeply sinuate-pinnatifid, sessile, scabrous ; flowers (small) solitary or most- 

 ly in loose clusters, not bracteolate ; petals obovate, scarcely exceeding the 

 short subulate-lanceolate calyx-segments ; filaments (20-30) all subulate- 

 filiform ; capsules cylindrical, narrow, elongated ; seeds 20-40. — Bartonia 

 albicaulis. Hook. ! fi. Bor.-Am. 1. p. 222. Trachyphytum albicaulis & 

 T. gracile ! Nutt. mss. 



Arid sandy plains of the Oregon, under the shade of Purshia tridentata, 

 Douglas. Plains of the Oregon and Rocky Mountains, Nuttall! June. — 

 Stern 6-10 inches high. Petals about 2 lines in length, yellow. — The pu- 

 bescence, although less in degree, is of two kinds, like that ofM. Lindleyi, &c. 



7. M. coTi.eesCa (Nutt. ! mss. under Trachyphytum) : " stem dichotomous, 

 smooth ; leaves short, ovate, somewhat pin!iatifid or incisely toothed, the up- 

 per ones clasping, bracts membranaceous, toothed, as long as the clusters of 

 (small) flowers ; capsules clavate-oblong, about 20-seeded. 



" Pv-ocky Mountains, on Lewis River, rare. — Flowers in sessile clusters, 

 3-5 together, enveloped by the membranaceous bracts. Calyx-segments 

 linear-lanceolate, acuminate. Petals 5, small, yellow." Nuttall. — Our 

 specimen is in fruit only. The stem is white and polished : the pubescence 

 as in M. Lindleyi, &c. Besides the sheathing floral leaf, there is a pair of 

 smaller bracteoles at the base of the calyx. 



§ 3. Seeds numerous, in a double series, compressed or winged, jive or more of 

 the exterior filaments dilated, often sterile and j^etaloid ; petals 5-10 ; the 

 inner series {transformed stamens ?) usually smaller: root mostly biennial. — 

 Bartonia, Nutt. not o/Willd. 



* Flowers vespertine, yellowish-white. 



8. M. ornafa : rough with short barbed hairs ; leaves oblong-lanceolate, 

 sessile, interruptedly sinuate-pinnatifid ; the segments rather acute ; flowers 

 (very large) terminating the branches, bracteolate ; petals 10, lanceolate- 

 ovate, concave and spreading, unguiculate, acute, the 5 inner ones somewhat 

 smaller, twice the length of the lanceolate calyx-segments ; filaments very 

 numerous, all filiform; capsules 5-7-valved at the summit; seeds numerous, 

 on 5-7 placentfE, compressed, scarcely margined. (Character arranged from 

 Nutt. g-er?.)— Bartonia ornata, Nutt. gen. 1. p. 297; Pursh, ft. 1. p. 326; 

 Bart. Jl. N. Amer. t. 81 ; DC. prodr. 3. p. 339. B. decapetala, Sims, hot. 

 inag. t. 1487. 



On the Missouri in argillaceous soil, Lewis, Nuttall. Aug.-Oct. — Root 

 succulent, fusiform. Stem 2-4 feet high, much branched. Flowers odorous, 

 vespertine : the petals about 2 inches long. Stamens 200-300. 



