GENESIS OP THE HORTULANAS 199 



conspicuously veiny below, and irregularly coarsely 

 toothed, and more or less obovate in outline, by a 

 late, very firm fruit, and by a more or less smooth 

 and Americana -like stone. I am not able to designate 

 the range of the wild plant, but it appears to occur 

 in Illinois (and perhaps Indiana), Missouri, Ten- 

 nessee, and perhaps in Arkansas." This sub-group 

 I called Prunus hortulana var. Mineri. The varie- 

 ties Miner and Forest Rose are typical of it. These 

 are so near Prunus Americana that Sargent refers 

 them to that species. In foliage and fruit they have 

 marks of the hortulana tribe, and I now regard them 

 as hybrids perhaps secondary ones which partake 

 very strongly of the Americana blood. 



One who diligently studies the native plums will 

 be impressed with the great variation which is asso- 

 ciated with change of climate or locality. In the 

 southern states, the flowers tend to appear wholly 

 in advance of the leaves, and they are borne upon 

 short stalks, or may be nearly or quite sessile. In 

 the North, the flowers and leaves are generally coeta- 

 neous, and the flower stalks are usually longer This 

 curious phenomenon, which is illustrated in the 

 accompanying engravings (Figs. 30, 31), is due to 

 the more sudden outburst of spring in the North, 

 by virtue of which all the latent energies of the plant 

 are pushed into simultaneous expansion*. The same 

 sudden outburst is seen in Prunus Americana (Fig. 

 32). This difference is often so pronounced in 

 botanical specimens of flowering shoots of the same 

 horticultural variety, taken in the South and the 

 North, that even good botanists may be confounded 



*See, also, "Survival of the Unlike," Essay XVII. 



