56 



THE AMERICAN BOTANIST 



RUDEBECKIA HIRTA forma FLAVESCENS f. nOV. 



Ray-flowers pale lemon yellow for the inner two-thirds of 

 their length; tips cream colored or nearly white. Otherwise 

 like normal plants. Found near Oak Forest, Illinois, and now 

 growing in the writer's garden. , ■ ■ . .J 



It is interesting to note that even in this specimen, there 

 is a marked difference in color between the outer and inner 

 portions of the rays as in the form piilcherrima (bicolor) 

 where the tips are yellow and the inner two-thirds are red. 

 The cause of this curious distribution of color is still a mys- 

 tery. A careful inspection of the ordinary normal form will 

 show many flower-heads with a deeper tint of yellow on the 

 base of the rays and in others where no apparent difference 

 exists, the camera can still distinguish a contrast. A similar 

 condition exists in many other flowers in this and allied gen- 

 era, but its utility is at present, a matter of speculation. 



POLYEMBRYONY IN OPUNTIA 

 RAFINESQUII 



By Edwin D. Hull. 



TN 1898, W. F. Ganongi Botanical Gazette) described in de- 

 tail from cultivated specimens polyembryony in Opuntia 

 vulgaris, the common prickly pear cactus of the Atlantic coast. 

 In 1899 in a brief note in Rhodora, he stated that possibly wild 

 plants are not polyembryonic and that it was not know^n that 

 O. Rafinesquii was polyembryonic at all. About 40% of the 

 seeds of the latter species gathered from plants on the sand 

 dunes of Lake Michigan at Miller, Indiana, August 1912, on 

 germination showed polyembryony, a percentage somewdiat 

 less than Ganong found in his material (about 50%). 



