270 PYRUS 



section is native of the New World: amygdaliformis, betulcefolia, 

 canescens, communis, cordata, elczagrifolia, glabra, heterophylla, Kotsch- 

 yana, longipes, Michauxi, nivalis, Pashia, salicifolia, sinaica, sinensis. 

 P. auricularis and P. malifolia are hybrids between this group and the 

 Aria group. 



The true pears include some of the tallest and bulkiest trees in the 

 genus, but the species as a whole have not such striking attributes for the 

 garden as some of the other sections. Their flowers are often beautiful, 

 but they have little attractive colouring in fruit, and the leaves frequently die 

 off black. Some, like P. salicifolia and P. nivea, are particularly effective 

 in their young expanding foliage, being covered with a snowy white, thick 

 down. The pears, although represented in N.E. Asia, are more particu- 

 larly identified with Europe especially S. and E. Europe Asia Minor, 

 and N. Africa. In that region there is a strong group, of which 

 P. amygdaliformis, nivalis, salicifolia, and glabra are leading types. 

 Seeds ripen freely, but owing to the hybrid origin of some it is safer to 

 graft the various sorts on their own or nearly allied seedlings especially 

 as many cultivated trees are of selected forms that could not be relied on 

 to come true from seed. 



II. ARIA. WHITEBEAMS. 



(Often united with Aucuparia and Aronia as SORBUS.) 



Trees and shrubs with simple leaves having distinct parallel veins, and 

 mostly more or less felted beneath. Styles free. Fruit in broad, flat 

 clusters. A group with the fruits pitted at the apex and with the calyx 

 fallen away have been separated under the name MICROMELES. 



Aria, Chamcemespilus, Hostii, intermedia, latifolia, minima, Mougeoti, 

 Torminalis, vestita. To the Micromeles section belong: alnifolia^ 

 caloneura, Folgneri. There are also the following hybrids : 



With the Aucuparia group decurrens, Meinichii, Neuillyensis, 

 pinnatifida. 



With the Aronia group alpina, Dippelii. 



With the Pyrophorum group auricularis, malifolia. 



The species belonging to the Aria group are as a rule handsome in 

 their large leaves, often white beneath, and in their fine masses of brightly 

 coloured fruit. The flowers are often of short duration. This group is 

 particularly well adapted for soil of a calcareous nature, most of them 

 occurring wild on a limestone formation. At the same time they thrive 

 in ordinary garden soil. In nurseries they are chiefly grafted on mountain 

 ash or white thorn, but plants raised from seed, although slow in their 

 early stages, are best in the long run. Between the leading species of 

 this group (P. Aria) and that of the next (P. Aucuparia) there is a whole 

 series of hybrid forms, some of natural origin. The first cross was 

 apparently P. pinnatifida, and from this, either by reversion to P. Aucuparia 

 ' or by recrossing with it, has been obtained P. decurrens and other forms, 

 all of which show their affinity to P. Aria in the felted under-surface of 

 the leaf, and to P. Aucuparia by having the leaves partly pinnate at 

 the apex. 



