ROOT- KILLING OF APPLE TREES. 459 



6. Chlorocarpa. Fruits either spherical or flattened-spherical; 

 when ripe, green, with red on the sunny side. 



7. Xanthocarpa. Fruits roundish-oval; when ripe, yellow; three- 

 quarters inch in length, less in breadth. 



8. Calvillea. Fruits oval or nearly spherical, ribbed, when ripe 

 scarlet-red, about one inch in length and breadth. In autumn this 

 variety is very handsome. The fruits are used for preserving; they 

 are very similar to P. baccata cerasi/era, but are distinguished by 

 the fact that the calyx segments do not fall off from the ripe fruit. 



Synonym: P. cerasifera, Tausich var. calvillea. 



9. Placrocarpa. The fruits are one inch in length and breadth, 

 nearly spherical, ribbed; when ripe, green. 



10. Striata. Fruits oval, one inch in length; when ripe, yellow 

 with dark red stripes. 



Byrus prunifolia flourishes in southeastern Russia and in south- 

 ern Siberia. It is propagated from seed. The varieties preserve 

 their characteristics only when grafted. 



Very similar is Pyrus spectabilis Ait., from China; this grows, 

 however, usually in bush form and is covered every year with 

 abundant reddish blossoms. 



P_yrus kaido, P. ringo and P. armeaiacifolia are garden varie- 

 ties; they are not resistant to our winters. 



The full history of Pj^ras baccaia and Pyrus prunifolia in a state 

 of nature and under cultivation is yet to be written. Since their in- 

 troduction into America they have been grown in mixed orchards, 

 especially in the western states, and very many hybrids with the 

 cultivated apples have originated under cultivation. Many of these 

 are too much subject to blight to be of value, while others are re- 

 garded as very valuable, especially in the prairie northwest, owing 

 to hardiness and productiveness. 



The true Pyrus baccata has been neglected, owing to small size 

 of fruit and ignorance of its value as a hardy stock. As to the orig- 

 inal home of these two species, Dippel gives eastern Siberia, China 

 and the Himalayas as the native home oi Pyrus baccata, and China 

 and Japan (p. 398) as that of Pyrua prunifolia. Fr. Th. Koeppen in 

 discussing the indigenous distribution in Russia of Pyrua malus 

 concludes as follows/ (page 417). "Finally in this connection should 

 be named Malus (Pyrus) prunifolia Willd., which form, according 

 to Regel, is said to grow in southeastern Russia (?) and in southern 

 Russia. Meanwhile frotn the whole Russian empire I find not a 

 single certain locality where it has been found (Fundortsangabe). 

 Ledebour gives only Siberia (and this with a question mark) as the 

 native habitat of this form." 



Prof. L. H. Bailey refers crabs of the Transcendent and Hyslop 

 type to P. prunilolia Willd., and considers them hybrids of the 

 common apple and Pyrus baccata. After a visit to Berlin Prof. 

 Bailey writes: 'Willdenow's type of P. prunifolia, preserved in 

 Berlin, shows flowers and leaves and has the botanical characters 

 of the Transcendent and Hyslop crabs. It is almost unmistakably 

 a hybrid of Pyrus malus and P. baccata. 



