HORTICULTURE AND PLANT IMPROVEMENT 5 



soms, and its fruits shading from green to black, it is found 

 along roadsides and in uncultivated corners everywhere. It 

 occurs in many forms. One species is very poisonous 

 and bears the name "deadly nightshade" or more properly 

 belladonna; it is not wild in North America, but many of 

 the species found here contain drugs of greater or less toxic 

 effect. There are many species of Solanum, which is the 

 principal genus of the nightshade family. Solanum nigrum, 

 variously known as black nightshade, stubbleberry, or garden 

 huckleberry, and Solanum carolinense (the horse nettle) are 

 two well-known plants of the genus; there are many kinds 

 known as weeds, others as greenhouse ornamentals, and the 

 eggplant and red pepper are also of this genus. 



The botanical divisions of plants require some explanation. Plants 

 are grouped into large divisions known as families. Each family 

 contains all those plants having a certain number of characteristics 

 in common. For example, the nightshade family, Solanacese, includes 

 all plants having the following characteristics: Herbs or shrubs with 

 colorless juice, and alternate leaves without stipules. Flowers regular 

 with parts in fives. Corolla with parts overlapping or touching by 

 contiguous edges in the bud. Ovary usually 2-celled. Style single. 

 Fruit a many seeded berry or capsule. Foliage strongly scented. Fruits 

 often poisonous, but some are edible. 



Families are again divided into groups called genera. For example, 

 the genus Solanum includes those plants in the nightshade family 

 having the following characteristics among others: Corolla wheel- 

 shaped, 5-parted or cleft. Stamens with short filaments and long 

 anthers, which often apparently unite around the style. Fruit usually 

 a berry. 



The genera are again divided into still smaller divisions called species. 

 For example, the species name "tuberosum" refers to the potato, 

 belonging to the genus "Solanum," of the Solafl&cese, and the botanist 

 writes the name of the potato Solanum tuberosum, giving the genus 

 name followed by the species name, capitalizing the genus name only 

 (when the species name is that of a person or a country, it may 

 be capitalized). Following are the characteristics of this species: 

 A perennial with underground tubers by which it propagates itself 

 asexually. Low-growing, much branched herbaceous tops. Leaves 

 unequally pinnate. Flowers in clusters, variable in color white, blue, 



