Flora of the Palouse Region 93 



shorter than the leaves; bracts oblong or obovate, obtuse, conspicuous: flow- 

 ers whitish or purplish, about 10 mm. long, on short pedicels which become 

 slender and elongate in fruit: calyx-tube campanulate, becoming cylindric, 

 the erect lobes acute, shorter: petals small, white: berry black, rather dry. 

 In woods, Thatuna Hills. 



Family 37. ROSACEAE. 



Herbs, shrubs or trees: leaves alternate, simple or compound, 

 usually with evident stipules often quickly deciduous: flowers 

 regular, mostly perfect, rarely polygamo-dioecious: calyx of 5, 

 rarely 3-8, sepals, united at the base, often surrounded by a row 

 of bractlets; calyx-tube lined by the disk: petals as many as the 

 sepals, rarely wanting, on the edge of the calyx-tube: stamens 

 usually numerous, distinct and free, or few and coherent with the 

 calyx-tube: carpels i-niany, distinct and free, or few and coherent 

 with the calyx-tube into a 2-several-celled inferior ovary: seeds 

 few or solitary; endosperm none, scanty or rarely copious. 



Pistil 1; style terminal: fruit a drupe. 165. prints. 



Pistils 2-5, united with each other and with the lower part of the receptacle 

 and calyx-tube, with which in fruit they form a pome. 

 Locules of mature pome, by false partitions, 10: shrub or tree, not 



thorny: flowers in racemes. 163. amrlanchikk. 



Locules of mature pome 1-5. 



Pome drupe-like, with bony kernels: thorny. 164. Crataegus. 

 Pome with papery or cartilaginous carpels; not thorny: flowers in 

 corymbs. 162. PIRUS. 



Pistils few, free, in fruit becoming dehiscent several-seeded follicles. 



Leaves palmate: pods 2-valved. 151. PHYSOCARPUS. 



Leaves simple or pinnate: pods i-valved. 



Ovules 5-11: disk free at the edge, not entire. 152. spiraea. 

 Ovules 2: disk wholly adherent, entire. 153. HOEODISCUS. 



Pistils many or few, rarely 1, free, 1-2-ovuled, in fruit becoming akenes. 

 Receptacle urn-shaped or spherical, fleshy: akenes numerous, enclosed 



in the receptacle and calyx-tube. 161. ROSA. 



Receptacle more or less urn-shaped, dry: akenes few, 1-4, enclosed in 

 the receptacle and calyx-tube: petals none. 

 Leaves palmately lobed. 155. alchemii.i. \. 



Leaves pinnately lobed. 156. poterh'm. 



Receptacle shield-shaped or slightly campanulate, the center convex, 

 bearing many akenes. 

 Calyx with 5 bractlets: akenes dry. 



Styles plumose or jointed, elongating in fruit. 



157- GEUM. 

 Styles neither jointed nor plumose, not elongating in fruit. 

 Receptacle dry: style terminal or lateral. 



-Style terminal or nearly so: ovules pendulous. 



158. potextii.i. \. 

 Style nearly basal: ovules ascending. 



159. DRYMOCAUJS. 

 Receptacle fleshy: style lateral. 160. fragaria. 



Calyx without bractlets: carpels becoming drupelets in fruit. 



154. Rrius. 



