360 GARDEN FLOWERS. 



up and divided. The tender species are of less moment, 

 except T. discolor, a curious stove species, and T. iridescens, 

 a pretty dwarf free-blooming greenhouse herb. 



T. subaspera (roughish) ; hardy perennial; 18 inches; flow- 

 ers purple, in May ; North America ; 1812. T. Virginica (Vir- 

 ginian) ; hardy perennial; 18 inches; flowers blue, in June; 

 North America ; 1629. 



This varies, with white, blue, red, crimson, and double- 

 blue flowers. 



TRAGOPOGON. [Composite.] A family of hardy bien- 

 nials, thriving in common garden soil. Propagated by seeds. 

 T. floccosus, mutabilis, and roseus are hardy border plants. 



TRAGOPYRUM. [Polygonaceag.] Hardy deciduous shrubs, 

 propagated by layers, and growing best in moist, peaty soil. 



T. buxifolium (box-leaved) ; 18 inches ; flowers white, in July; 

 Siberia; 1800. T. lanceolatum (spear-shaped); 2 feet ; flowers 

 pink, in July; Siberia; 1778. 



TREE-PEONY. See MOUTAN. 



TREFOIL. See TRIFOLIUM. 



TRIENTALIS. [Primulaceae.] A family of delicate little 

 perennials, grown best in a shady situation in leaf-mould. 

 Propagated by division. 



T. Americana (American) ; 6 inches ; flowers white, in June ; 

 North America ; 1816. The European species (T. Europcea) 

 much resembles this. 



TRIFOLIUM. Trefoil, or Clover. [Leguminosae.] Hardy 

 herbs, many of which are annuals or biennials, and a large 

 number perennials. They are not of much value as garden 

 plants. T. incarnatum, with its scarlet flower-heads, is 

 showy ; and T. uniflorum is a very pretty minute perennial 

 species, deserving a place among alpines. The annuals may 

 be sown in April in the places where they are to flower. 

 The perennials need only to be planted in ordinary soil. 



