228 THE SAL VIA. ASCLEPIAS. APIOS. 



C. communis. Flowers bluish purple. 



C. tuberosa. Flowers blue. 



There are many other species, mostly with blue flowers. 



SAL VIA. 



One species of the salvia, S. patens, has a tuberous root. 

 The seeds should be sown in the greenhouse or a frame in 

 April, and the plants pricked out into the garden, where 

 they bloom the first year. On the approach of cold weather, 

 they should be taken up, and treated as directed for comme- 

 lina. 



ASCLEPIAS. 



One species of the silkworts, or milkweeds, is a hardy 

 tuber. 



Asclepias tuberosa is one of the most showy plants in the 

 garden in July. The flowers are deep orange. The plant 

 is hardy, and, once well established, will bloom freely for 

 years. It delights in a rich, deep, light soil, in which the 

 roots strike to a great depth. 



APIOS. 



A. tuberosa is a pretty, pea-like vine, with hard tuberous 

 roots, commonly known as " ground-nuts." The plant is 



