Flora of the Palouse Region 119 



ent to the ovary: stamens usually very numerous, rarely few, some 

 of the outer occasionally petal-like: ovary 1 -celled, with 2-3 

 parietal placentae: endosperm mostly scant or none. 



193. MENTZELIA. 



Annual or biennial erect herbs, more or less rough with rigid 

 barbed hairs, the stems becoming white and shining: leaves alter- 

 nate, mostly coarsely toothed or pinnatifid: flowers terminal, soli- 

 tary or in cymose clusters: calyx cylindrical, 5-parted: petals 5 or 

 10, regular, spreading, perigynons: stamens perig3 r nous: styles 3, 

 more or less united into one: capsule few-many-seeded. 



Flowers large, 6-8 cm. broad. M. i.aevicauxis. 



Flowers small, 6-8 mm. broad. M. dispersa. 



M. laevieaulis Torr & Gray. Biennial: stem stout, erect, 30-100 cm. 

 high, hoary-pubescent throughout or glabrate, branched above: radical 

 leaves lanceolate, acute, petioled, 10-15 cm - l° n g. coarsely dentate or lobed, 

 hoary-pubescent: cauline similar, sessile, gradually reduced upwards: flow- 

 ers nearly sessile, terminal, mostly solitary: calyx-lobes lanceolate-attenuate, 

 2-3 cm. long: outer petals lanceolate, acute, tapering at the base, 3-6 cm. 

 long: inner petals, when present, narrow: stamens numerous, as long as the 

 style, shorter than the petals: capsule oblong, about 2 cm. long. Gravelly 

 places near Colfax and along Snake River. 



M. dispersa Wats. Annual, puberulent throughout: stem white, erect, 

 rarely decumbent, sparingly branched, 10-40 cm. high: leaves oblong or 

 lanceolate or the upper ovate, entire or sinuately pinnatifid, 2-6 cm. long, 

 sessile: flowers yellow, sessile or nearly so, in leafy cymes, 6-10 mm. broad: 

 calyx-lobes deltoid-lanceolate, shorter than the petals: capsule linear, 2-3 

 mm. long: seeds nearly cubical, smooth, grooved on the angles. Drv soil, 

 Wawawai and Cedar Mountain. 



Family 52. CACTACEAK. 



Fleshy and thickened plants: stems flattened, terete, ridged or 

 tubercled, continuous or jointed, leafless or with small leaves, 

 generally spiny: spines from cushions of minute bristles: flowers 

 solitary, sessile, perfect, regular, showy: sepals and petals numer- 

 ous, in several rows, the bases adherent to the ovary: stamens 

 numerous, on the calyx-tube: style 1; ovary 1 -celled, with several 

 parietal placentae: ovules numerous: fruit a 1 -celled berry: endos- 

 perm scanty or copious. 



194. OPUNTIA. 



Jointed, much-branched plants: leaves small, terete, subulate, 

 early deciduous, on young branches: flowers usually lateral, large: 

 calyx-tube not prolonged beyond the ovary; lobes numerous, 

 spreading: petals numerous, slightly united: stamens very numer- 

 ous, in several rows: fruit a berry, often prickly. 



