GARDEN FLOWERS. 197 



HOUND'S -TONGUE. See CYNOGLOSSUM. 



HOUSE-LEEK. See SEMPERVIVUM. 



HOUSTONIA. [Cinchonaceae.] Pretty little tufted peren- 

 nial herbs. Soil, a sandy mixture of three parts peat to one 

 of loam. Increased by division. 



H. cosrulea (blue) ; hardy perennial ; 3 inches ; flowers bluish- 

 lilac, in May; North America; 1785. H. purpurea (purple); 

 hardy perennial ; i foot ; flowers purple, in May ; North Amer- 

 ica ; 1 800. H. serpyllifolia (thyme-leaved) ; tender perennial ; 

 6 inches ; flowers white, in May ; North America ; 1826. 



These plants are now called Oldenlandia, and are rather 

 insignificant singly, but in the mass are showy. H. ccerulea 

 is the species which in spring almost whitens the pastures. 

 H. serpyllifolia^ a Southern species, is tender and of little 

 value. 



HAGELIA. [Polemoniaceae.] Dwarf hardy annuals, allied 

 to Gilea, and thriving under the same treatment. Sow in 

 light border soil in May. 



H. densiflora (dense-flowered) ; hardy annual ; I foot ; flow- 

 ers blue, in July ; California ; 1 833. H. elongata (lengthened) ; 

 hardy annual ; i foot ; flowers deep-blue, in July ; California ; 

 1833. H. lanata (woolly) ; hardy annual ; i foot ; flowers light- 

 blue, in July; California; 1847. //. hitea (yellow); hardy an- 

 nual; 6 inches ; flowers yellow, in July; California; 1833. H. 

 virgata (twiggy) ; hardy annual ; I foot ; flowers deep-blue, in 

 July; California; 1333. 



HUMEA. [Compositae.] A greenhouse biennial of sin- 

 gular grace and beauty. The seeds should be sown in May, 

 and for a year potted from smaller to larger pots, win- 

 tered in a cold frame, and in May turned into the border in 

 a sheltered situation. They will grow from eight to ten feet 

 high. Others may be potted in twelve-inch pots, with loam 

 and dung in equal parts for the compost. Those in pots 

 must be regularly supplied with water, because they will 



