224 



FOUNDATIONS OF BOTANY 



1. S. perfoliata, A. DC. Specularia. Stem erect, simple or 

 branched from the base, angles roughened, 10-20 in. high. Leaves 

 ovate to lanceolate, acute at the apex, sessile, crenate or entire, the 

 upper bract-like. Flowers solitary or in pairs. Corolla blue, often 

 wanting. Capsule cylindrical, smaller above. In waste places.* 



100. COMPOSIT.a;. Composite Family. 



Flowers in a dense head, on a common receptacle, sur- 

 rounded by an involucre composed of many bracts (Fig. 22), 



Fig. 22. — Flower-cluster of Bachelor's Button {Centavurea Cycmus). 



