156 GARDEN FLOWERS. 



nials, generally hardy, remarkable for the colored bracts of 

 the involucre, which constitute the showy part of their in- 

 florescence. They are desirable among hardy herbaceous 

 subjects, the prevailing color being blue. They belong, in 

 truth, to the umbelliferous order, without having any ex- 

 ternal resemblance to that class of forms so familiar in the 

 Parsley, the Celery, the Carrot, and the Fennel. They are 

 raised from seeds, which, like those of other perennials, may 

 be sown in May either in pots or in a bed. The young 

 plants, if nursed into strength, will bloom the following year; 

 but, usually, the old plants are the best if they are kept in 

 vigor. They are not very particular as to soil ; but a deep 

 sandy loam is best. 



E. Alpinum (Alpine) ; hardy perennial ; 2 feet ; flower-heads 

 blue, in July ; Switzerland ; 1597. E. amethystinum (ame- 

 thystine) ; hardy perennial ; 3 feet ; flower-heads blue, in July ; 

 Styria ; 1648. E. Bourgati (Bourgati's) ; hardy perennial ; 2 

 feet; flower-heads blue, in July; south of France; 1731. E. 

 caruleum (sky-blue) ; hardy perennial ; 2 feet ; flower-heads 

 blue, in July; Caspian; 1816. E. giganteum (giant); hardy 

 perennial; 4 feet ; flower-heads blue, in July ; Caucasus; 1820. 

 E. planum (flat-leaved) ; hardy perennial ; 3 feet ; flower-heads 

 blue, in July ; Europe ; 1596. 



There are numerous other hardy perennial species. 



ERYSIMUM. Hedge Mustard. [Cruciferae.] Hardy plants, 

 chiefly biennial, those which are cultivated being treated as 

 annuals : the majority are uninteresting objects. E. Pcroff- 

 skianum is, however, a very brilliant-flowered plant, well 

 adapted for beds in gardens : indeed, there is hardly any 

 other plant which furnishes the color, an intense orange. 

 It is perfectly hardy, and, if sown in the spring, will bloom 

 in June and July. It will bloom much earlier if sown in 

 pots like a half-hardy annual, and turned out in May ; for it 

 will then begin flowering in the pots in May. The plant is 



