GARDEN FLOWERS. 155 



They prefer light and rather sandy soil. When grown in 

 pots, they should have the protection usually given to al- 

 pines, which consists mainly in plunging the pots to prevent 

 frosts from acting on the roots, and in shielding off heavy 

 rains, which saturate the soil, and sometimes, if the drainage 

 gets deranged, become conducive to the decay of the plants 

 by rotting the roots and root-stocks. They are increased by 

 division, which should be done about July or August, or 

 by seeds sown as soon as they ripen. The greenhouse sub- 

 shrubby species are referred to Nycterinia. 



E. Alpinus (smooth) ; hardy perennial; 3 inches ; flowers rose- 

 purple, in April ; Pyrenees ; 1739. E - Hispanicus (hairy) ; hardy 

 perennial ; 6 inches ; flowers rose-color, in March ; Spain ; 1739. 



These plants are half-hardy in^the Northern States. 



ERIOGONUM. [Polygonacece.] Half-hardy herbaceous 

 perennials, increased by division and seed. Soil, peaty 

 loam. 



E. compositum (compound) ; hardy perennial ; 18 inches ; 

 flowers yellowish-white, in May ; North America. E. longi- 

 folium (long-leaved) ; hardy perennial'; 2 feet ; flowers yellow, 

 in June; North America; 1824. E. sericeum (silky); hardy 

 perennial; i foot; flowers yellow, in July; Missouri; 1811. 

 E. tomentosum (downy) ; hardy perennial ; 2 feet ; flowers 

 white, in May ; Carolina ; 1811. 



ERIOPHORUM. Cotton-grass. [Cyperaceae.] Very pretty 

 hardy herbaceous perennials, producing heads of silver)' 

 white plumes, which might be effective planted in low 

 ground. Increased by division and seed. Soil, wet loamy 

 peat. 



EROPHILA. [Cruciferae.] Hardy annuals, allied to Draba, 

 growing from seed, in garden soil. Flowers white. The 

 species are E. Americana, precox, and vulgaris. . 



ERYNGIUM. [Umbelliferae.] A curious genus of peren- 



