56 



Introduction to Botany. 



or Missouri Currant, Flowers several in leafy-bracted racemes, yellow, spicy- 

 scented, i to I inch long. Calyx tube cylindric, about 3 times as long as the lobes. 

 Fruit smooth, yellow, becoming black. Along streams. 



ROSACEA. Rose Family. 



Herbs, trees, or shrubs with alternate, mostly stipulate, leaves. 

 Flowers regular ; sepals 5, often subtended by as many sepal-like 

 bractlets ; petals 5, apparently inserted on the calyx ; stamens usually 

 indefinite, apparently inserted on the calyx (expanded border of the 

 base of the receptacle). Pistils i-many, distinct or united. Some of 

 our most beautiful flowers and best fruits belong to this family. 



Longitudinal diagrams of type flowers of the Rosaceae. A, plum; 

 B, rose ; C, strawberry. 



Ovary superior or half superior. 



Ripened pistil a drupe or drupelet. 



Fruit consisting of a single pistil. 



Fruit consisting of several pistils cohering over an elongated receptacle. 

 Ripened pistil a few- to several-seeded pod. 



Pistils 5-8; pods not Inflated. 



Prunus I. 

 RUBUS IV. 



Spir^a II. 



Pistils 1-5; pods inflated. Phvsocarpus III. 



Ripened pistil an achene. 



Carpels distinct and numerous on a convex receptacle, which becomes fleshy and edible 



in fruit. Fragaria V. 



Carpels distinct on a dry receptacle ; styles not lengthening in fruit ; bracts conspicuous 



at the sinuses of the calyx. Potentilla VI. 



Carpels 2-6 on a short receptacle; styles not lengthening in fruit; bracts at the sinuses 



of the calyx minute or wanting. Waldstetnia VIT. 



Carpels numerous on a dry conical or cylindrical receptacle ; style persisting as a hairy 



or jointed tail to the achene. Geum VIII. 



Ovary inferior. 



Pistils several, Inclosed in an urn-shaped receptacle. Rosa IX. 



Pistil single, compound, its cells as many as the styles (2-5). 



Fruit a pome; ovary 5-ceIled, its carpels 2-seeded. Pyrus X. 



Fruit a small, berrylike pome; ovary becoming lo-celled, its carpels 2-seeded. 



Amelanchier XI. 

 Fruit a small, drupelike pome with 1-5 bony stones. Crataegus XII. 



