CUP FLOWERS 313 



and the five-petaled corolla, tubular below, but open 



and flat above. The five stamens are borne on the inside 



of the tubular part of the corolla, and their anthers are 



united around the style, as in the 



Sunflower. The ovule also is 



quite like that in the Sunflower. 



On ripening the upper part of 



the cup becomes prolonged into 



a slender beak far beyond the 



ovary carrying the spreading ^^^ ^^^ 



calyx whorl upon its summit, 



and forming a veritable parachute which readily carries 



away the achene and its seed in even the lightest of 



breezes. 



577. Here it may be remarked that the Dandelion 

 shows the highest development of flower structure found 

 in the Anthophyta, and so it may be considered as the 

 highest plant in the Vegetable Kingdom. 



Laboratory Studies, (a) With longitudinal sections of the 

 flowers of Spiraea make out especially the thickened cup (torus), 

 the smaller number of several-seeded carpels (five), and the 

 man}' stamens. 



(6) Examine externally and in longitudinal section flowers 

 and "apples" of any rose (Rosa). Note the great number of 

 one-seeded carpels (resembling those of Strawberry), and sta- 

 mens, and the deeply hoUowed out, fleshy, receptacular cup, 

 comparing with S])iraea. 



(c) Making comparisons with the Rose examine in a similar 

 way tlic flowers and fruit of the Apple (Mains), or Pear (Pirus), 

 Quince (Cydonia) or Hawthorn (Crataegus), noting especially 

 the great thickening of the torus and its adherence to the five 

 united carpels. 



(d) Make vertical sections of Plum flowers (Prunus) so as 

 to show the single free pistil (of one carpel) at the bottom of the 

 cup, and the many stamens on its margin. Make cross-sections 

 of growing ])lums (fruits) showing stony cndocarp, and fleshy 



