CUP FLOWERS 



311 



pistillate flower in each scaly cup-like involucre consists of 

 a tricarpellary pistil, wholly covered by a thin cup 

 bearing on its margin the very minute perianth (calyx). 

 The fruit is a thin, tough-shelled nut ("acorn") usually 

 with but one large seed. The ripe acorn rests in the 

 enlarged scaly involucre, now known as the acorn cup. 



Fig. 190. — Quercus. 



Fig. 191. — Pastinaca. 



673. In the Parsnip (Pastinaca) the small flowers are 

 clustered at the ends of slender spreading rays (in an 

 umbel) . The bicarpellary pistil is covered with the thin 

 cup, on the margin of which are the five very minute 

 sepals, the five yellow petals, and the five elongated 

 stamens. Each carpel cavity contains a single pendulous 

 ovule. In ripening the bicarpellary ovary becomes much 

 flattened (dorsally) so that each carpel becomes winged 

 marginally, and later the two carpels split apart. 



574. The flower of the Honeysuckle (Lonicera) has its 

 bi- or tricarpellary pistil covered with the 

 deep cup, as in the preceding plants. The 

 five sepals on the cup margin are very small, 

 and the five petals are united into a tube 

 which widens upward to its irregular mar- 

 gin. The five stamens are attached to the 

 inside of the corolla tube. On ripening, 

 the cup and enclosed ovary develop into a 

 fleshy few-seeded berry. 



576. In the Sunflower (Helianthus) which is one of 

 the lowest members of the highest order (Asterales) of 



