Addisonia 57 



(Plate 149) 

 CENTAUREA MONTANA 



Mountain Bluet 



Native of Europe 

 Family Carduac^ae Thistle Family 



Centaurea montana L. Sp. PI. 1911. 1753. 



A stoloniferous perennial plant, with tough roots and rootlets. 

 The stems are one to two feet high, green, covered with short 

 stiff hairs, especially above, markedly five-angled, the angles run- 

 ning up into winged bases of the strongly decurrent upper leaves; 

 these are lanceolate, acute, lightly dentate, and hairy, almost woolly 

 beneath, deep green above and light green beneath, and vary in 

 length from two to eight inches. The basal leaves are sessile, 

 narrowed at the base, and up to one foot long. The flower-heads 

 are terminal or on short peduncles in the axils of the upper leaves, 

 one or two inches in diameter, and blue to purple. The involucres 

 are turbinate, consisting of about six rows of triangular, acute, 

 green bracts, purple near the tips, with black, ciliate, straw-like 

 margins. The blue-purple ray flowers have tubular, unequally 

 five-lobed ligules, the lobes spreading. The red-purple disks, 

 with the black stamens prominent, are composed of many perfect, 

 tubular, lobed flowers. The achenes are smooth and cylindric, 

 the pappus of many series of bristles. 



The genus Centaurea, with more than three hundred species, has 

 contributed freely to our gardens. We have the corn-flower, C. 

 Cyanus; the knapweeds, C. nigra and others; C. americana, a large, 

 yellow-flowered native annual, always popular; and many interest- 

 ing European and Asiatic species. 



Centaurea montana, one of our common garden perennials, has 

 been cultivated for centuries. Alton, in the Hortus Kewensis, 

 says it was grown by Gerard, as early as 1596. There are several 

 varieties, alha, rosea, and citrina, in cultivation, being white, pink 

 and yellow forms. A few plants furnish hundreds of blooms in 

 early summer; then in September they renew their growth and 

 bloom for another month or two. This is one of the easiest of 

 plants to grow, often spreading rapidly and covering space not 

 intended for it. 



The illustration was taken from plants growing in the flower- 

 borders of the New York Botanical Garden since 1913. 



Kenneth R. Boynton. 



Explanation op Plate. Fig. 1. — Flowering stem. Fig. 2. — Ray-flower. 

 Fig. 3. — Disk-flower. 



