204 CISTACEAE 



through the apex to form a short point, and narrowed at the 

 base to very short petioles. 



The flowers, which appear from about the last of June on 

 through most of August, are solitary or in 1 or more pairs 

 in the axils of the uppermost leaves, or they also may occur in 

 small clusters that terminate the branchlets. The bright yellow 

 flowers are generally about ^ inch wide and stand on pedicels 

 about 1/^ inch long. The fruit, which matures in autumn, is a 

 3-celled capsule up to Yi inch long, containing many oblong or 

 often curved seeds, the surfaces of which bear numerous pits 

 arranged in lengthwise lines. 



Distribution. — The Shrubby St. John's-Wort grows in low 

 places, especially about small lakes and marshes, and prefers 

 shaded to open situations. It ranges from southern Ontario 

 to Minnesota and south to Georgia and Mississippi. It ranges 

 through most of Illinois as a widely distributed but infrequent 

 and localized shrub, which tends to occur individually rather 

 than in groups. It has not been reported, however, in the region 

 north and west of the Rock River. 



CISTACEAE 

 The Rock-Rose Family 



Members of the rock-rose family are either shrubs or low 

 undershrubs with alternate or opposite leaves and nearly regu- 

 lar, usually perfect flowers borne either solitarily or in various 

 types of inflorescences. The flowers are made up of 3 to 5 

 persistent sepals and of 3 or 5 petals, which are soon lost and 

 may sometimes be wanting. The stamens are 8 in number, 

 and the ovary consists of several united pistils which develop 

 into a capsule containing several or many seeds. 



The more than 150 species in this family are divided into 

 about 8 genera, 3 of which occur in northeastern North America. 

 In Illinois, the following is the single shrubby genus. 



HUDSONIA Linnaeus 



Beach Heather 



The beach heathers are low, tufted, much-branched shrubs 

 with small, scalelike, persistent leaves and small, regular, per- 

 fect flowers, which terminate branches. The flowers have 5 



