Addisonia 25 



(Plate 93) 



HELIANTHUS ORGYALIS 



Linear-leaved Sunflower 



Native of south-central and western United States 

 Family Carduac^a^ Thistle; Family 



Helianthus orgyalis DC. Prodr. 5: 586. 1836. 



A tall perennial herb, from widely spreading rootstocks. The leafy 

 stems are glabrous, somewhat glaucous, striate, slender but strong, 

 six to ten feet high and much branched above. The leaves are 

 alternate, sessile, linear, acuminate, with a few scattered shallow 

 teeth; they are less than one half inch wide and up to eight inches 

 long, recurved and drooping, and rough with pointed papillae, 

 especially on the lower surfaces. The branching inflorescence bears 

 many heads of flowers, which are about two inches across, the 

 neutral ray-flowers being very conspicuous, ten or more in number, 

 with ligules an inch long, a half inch wide, and rich yellow in color. 

 The disks are small, dark brown or purple, made up of several 

 perfect, fertile flowers with yellow tubes swollen near the base, and 

 four or five brownish spreading lobes surrounding the erect brown 

 anthers and a prominent, two-parted yellow style. The heads are 

 surrounded by involucres of bracts in many series; these are 

 spreading, lanceolate to subulate, squarrose and with ciliate margins. 

 The receptacles are convex, with laciniate-toothed chaff. The 

 achenes are four-sided, truncate, with a pappus of a few scales. 



This sunflower was first described by DeCandolle from a culti- 

 vated specimen in the botanic garden at Geneva, said to have 

 been grown from seed sent from Arkansas Territory by M. de 

 Pourtales. It grows naturally on the dry plains from Nebraska to 

 Texas and westward. With the graceful habit of a Coreopsis, it 

 has none of the coarseness of many of the sunflowers. Its tall 

 slender stems, arching leaves, and many bright yellow flowers 

 make it one of our best perennials for the background of deep 

 borders. 



Plants growing in our borders since 1911 furnished the specimen 

 for our illustration. The blooming period here is September and 

 October. Their propagation is best effected by division of the roots 

 and their cultivation is simple. 



Kenneth R. Boynton. 



