104 THE AMERICAN BOTANIST 



red in them to take on a purplish hue, but the flax is clear 

 blue, only, and therefore most desirable. 



Flower Color Identified. — According to a recent re- 

 port, flowers are colored blue by meta-oxy-diethyl-diamido- 

 phenyl-ditolyl-carbinol-disulphonic acid. It is very evident 

 that the science of chemistry is badly in need of a Linnaeus. 



White Cypripedium Acaule. — Mr. MacNamara's 

 white Cypripedium acaule is a very common flower in this 

 region. I have seen more than thirty this last June, had 

 twelve in my room for several days, and Air. Walter Deane 

 tells me that on a mountain, close by, white and pink flowers 

 grow near the base, then more white and fewer pink as one 

 ascends the slope and near the top they are all white; not a 

 pink flower to be found. When prepared for herbarium use 

 the white blossoms turn pink and when they begin to fade or 

 ripen in water, the white blossoms show either veins of pink 

 or a slight flush of pink.— Mm Caroline G. Soule, Shelburne, 

 N. H. 



A Double Rudbeckia. — This time the expected has hap- 

 pened. Mr. George Redles has found a completely double 

 flower-head of Rudbeckia hirta, at Somerton, Philadelphia. 

 From an examination of the flower, which he kindly forwarded, 

 we find it to be a true doubling, as the word is used with 

 reference to composites, and not a freak due to the attacks of 

 gall-flies or fungi. A half double form is illustrated on page 

 533 of Gagers "Fundamentals of Botany," but Mr. Redles 

 appears to be the first to report a completely double form. The 

 plant has been transferred to the garden where it is hoped it 

 will increase in luxuriance. It may be said in passing that 

 although the flower-head resembles a prize chrysanthemum in 

 miniature it is not really double in the sense that a rose is 

 double. There are no extra parts present. The disk flowers 

 have simply taken on the form of the rays. The form might 

 be called Rudbeckia hirta multiligula instead of the usual flora 

 plena which the gardener applies to all sorts of double flowers. 



