250 RUBIACEAE 



perfect, regular, symmetrical flowers. The calyx Is small, with 

 its 4 or 5 sepals more or less united and adnate to the ovary, 

 and the corolla consists of a long or short tube of 4 or 5 petals, 

 which are separated to varying degrees. Alternate with the 

 petals are 4 or 5 stamens. The ovary is 1- to 10-celled and 

 develops into a capsule, a berry or a drupe containing 1 to 

 many seeds. 



There are more than 6,000 species in this family, which rep- 

 resent nearly 350 genera and have a very wide distribution, 

 especially in the tropics. The following is the only shrubby 

 form in Illinois. 



CEPHALANTHUS Linnaeus 

 The Buttonbushes 



The buttonbushes are shrubs or small trees with 4-angled 

 branches and opposite or, rarely, whorled, entire leaves. The 

 perfect flowers are axillary or terminal and are borne singly 

 or in densely panicled heads. There are 4 sepals, and the white 

 or yellowish, funnel-shaped corolla is tipped by 4 lobes. The 

 4 stamens are adnate to the throat of the corolla, and the 

 2-celled ovary develops into a dry fruit, which broadens from 

 the base upward and contains 2 to 4 nutlets. 



The seven species of buttonbush are natives chiefly of Asia. 

 Only one occurs in North America. 



CEPHALANTHUS OCCIDENTALIS Linnaeus 

 Buttonbush Honeyballs Globeflower 



The Buttonbush, fig. 66, is a large, spreading shrub, in 

 southern Illinois almost of tree size but commonly 4 to 15 

 feet high, with usually furrowed bark and smooth branchlets 

 on which the leaves are opposite or whorled. The ovate to 

 lanceolate leaves stand on petioles 14 to ^ inch long and 

 usually point forward along the branches. The leaf blades 

 are entire on the margins, acute or acuminate at the apex, 

 rounded or narrowed at the base, 3 to 6 inches long by li/^ 

 to 3 inches wide, smooth and dark green above, and light 

 green and more or less hairy on the midrib and veins be- 

 neath. 



The flowers are borne in globular heads of as many as 200 



