LOASACE^E. 107 



1. MENTZELIA, L. 



Calyx-tube cylindrical or turbiuate: the limb 5-lobed. Petals 5 or 10. 

 Stamens inserted below the petals on the throat of the calyx. Ovary trun- 

 cate at the summit : style 3-cleft, the lobes often twisted. Capsule opening 

 usually irregularly at the apex. Erect, the stems becoming white and shin- 

 ing : leaves alternate, mostly coarsely toothed or pinnatifid : flowers cymose or 

 solitary, orange or golden yellow to white. 



# Seeds few, oblong, not winged : petals 5, not large : filaments all filiform : 



leaves petioled, cut-toothed or angled. 



1. M. oligosperma, Nutt. Rough and adhesive, 1 to 3 feet high, much 

 branched, branches brittle : leaves ovate and oblong : petals yellow, wedge- 

 oblong, pointed: capsule about 9-seeded. From the mountains eastward 

 across the plains to Illinois and Texas. 



# * Seeds few to many, irregularly angled or somewhat cubical, not winged: 



petals 5, not large: filaments all filiform: capsule linear: leaves sessile, sin- 

 uately toothed or pinnatifid. 



2. M. albicaulis, Dougl. Slender, 3 inches to a foot high or more: 

 leaves linear-lanceolate, pinnatifid with numerous narrow lobes, upper leaves 

 broader : flowers mostly approximate near the ends of the branches : petals 

 spatulate or obovate : capsule linear- clavate: seeds numerous, rather strongly 

 tuberculate, irregularly angled with obtuse margins. Torr. & Gray, Fl. i. 534. 

 From New Mexico and Colorado to Oregon and California. 



3. M. dispersa, Watson. Very similar, but the leaves sinuate-toothed, 

 sometimes entire, rarely pinnatifid, the uppermost often ovate : seeds somewhat 

 cubical and very nearly smoolli. Proc. Am. Acad. xi. 115. M. albicaulis, var. 

 integrifolia, Watson. From Colorado through Idaho to Washington Terr, and 

 California. 



# * * Seeds numerous, suborbicular-winged or narrowly-margined : petals 5 or 10, 



often large and showy : outer filaments often petaloid : capsule broad, oblong : 

 leaves as in the last. 



H- Flowers vespertine, yellowish white. 



4. M. ornata, Torr. & Gray. Rough with short-barbed hairs : leaves 

 oblong-lanceolate, the segments rather acute : flowers very large, terminating the 

 branches, bracteolate: petals 10, about 2 inches long : filaments all filiform: 

 capsule 5 to 7-valved at the summit : seeds scarcely margined. Fl. i. 534. 

 Along the Missouri and its tributaries ; also in S. W. Colorado. 



5. M. nuda, Torr. & Gray. Rough with minute barbed pubescence: 

 leaves somewhat lanceolate, the segments obtuse : flowers about half the size of 

 the last, not brac.teol ate: petals 10: exterior filaments petaloid and often sterile: 

 capsule 3-vahed at the summit : seeds plainly winged. Loc. cit. 535. 



*- -<- Flowers expanding only in bright sunshine, bright yellow: leaves lanceolate. 



6. M. laevicaulis, Torr. & Gray. Stout, 2 or 3 feet high: flowers sessile 

 on short branches, very large: calyx-tube naked: petals acute at each end, 2 to 

 2^ inches long: seeds very minutely tuberculate. Loc. cit. W. Wyoming 

 and Montana to the Columbia River and S. California. 



7. M. pumila, Torr. & Gray. Rather stout, 8 to 10 inches high: lower 

 leaves somewhat petioled : flowers small, solitary or three together, terminating 



