Sterile Varieties. 91 



are destitute of flowers; and the thin, transparent bracts 

 are transformed into small green leaves. The variety 

 is much cultivated in gardens, partly as a curiosity and 

 partly because their green ''flowers" do not wither but 

 remain fresh on the plant; which renders it of a decora- 

 tive effect until far into the autumn.^ The variety arose 

 in a crop of seedlings about the middle of the last cen- 

 tury in Boskoop in Holland, and since then has been 

 grown from tubers. It occasionally bears isolated red 

 ray florets but, so far as I know, never sets seed. 



Some years ago I obtained what seems to be a new 

 and hitherto undescribed form of green Dahlia through 

 the kindness of Messrs. Zocher «& Co. in Haarlem. It 

 is not known whence this form came because it was at 

 first taken for the type of green Dahlia we have just 

 been considering. It differs from this however in the 

 fact that the green heads are not of the normal form 

 and size but transformed into long green leaf-bearing 

 spikes like that figured in Fig. 14 with the exception of 

 the clump at the top. 



This form produced elongated flowers of this kind in 

 great numbers in the nursery garden ; but it could never, 

 so to speak, bring its growth to a conclusion. They grow 

 until the autumn and often longer, and frequently attain 

 a length of 30 centimeters and more. They behaved in 

 exactly the same way in my garden until last year when 

 I manured them heavily. Then there appeared from a 

 few of the green ''flowers" in late autumn a little head 

 at the uppermost end (Fig. 14). This unfolded, but 

 consisted of green bracts only ; it contained neither flow- 

 ers nor seeds. The plant is therefore perfectly sterile. 



Another variety closely analogous with this is the 



^ See the literature in Penzig's Teratologic, TI, p. 71. 



