February 5, 1910 



HORTICULTURE 



181 



Plant Novelties From China 



The outstanding feature of the Chinese flora is its 

 remarkable richness in ornamental trees and shrubs suit- 

 able for cultivation in the gardens of temperate lands. 

 jSTo other flora is anything like as rich in this respect. 

 The climate of China is continental in character, and in 

 the central and western parts above 4.000 ft. altitude, 

 approximates very closely to what obtains here in New 

 England. These parts of China are extremely moun- 

 tainous, in fact they are nothing but vast seas of moun- 

 tains — range upon range, separated by narrow valleys, 

 and increasing in altitude westward until they culminate 

 in the perpetual snows of the Chino-Thibetan border- 

 land. The average rain-fall is about 40 inches and the 

 snow lays on the gi'ound from late November until early 

 April. The most marked difference between the two 

 climates is perhaps the more constant nature of the 

 snow-fall in western China and less changeable weather 

 generally in winter. 



Various causes, chiefly, however, the clearing of land 

 for agricultural purposes and the general absence of 

 coal-mining in the past, have led to the almost entire 

 deforestation of China except in the wildest and most 

 inaccessible parts. But so suitable is the climate for the 

 growth of ligneous vegetation that clearings neglected 

 for a little time speedily become dense thickets com- 

 posed of miscellaneous shrubs and small trees. The 

 steep, uncultivatable cliffs, etc., are clothed with similar 

 vegetation. It is in these thickets that the astonishing 

 rich variety of shnibs is found. The question of the 

 hardiness of these new Chinese trees and shrubs is one 

 of supreme importance to prospective cultivators in this 

 country and the solution lies in actual experiment. In 

 England these plants have proved, almost without ex- 

 ception, perfectly hardy. Now as a general rule decid- 

 uous trees and shrubs thrive better in this neighborhood 

 than across the water. For example, Cercidophyllum, 

 japonicum, Dirca palustris and Symplocos crataegoides 

 are perfectly hardy in the Arnold Arboretum whereas in 

 England they are regarded as tender. Analog^' there- 

 fore suggests that the majority of these new deciduous 

 trees and shrubs will prove hardy, suitable and amena- 

 ble to cultivation hereabouts. As every cultivator knows 

 much can be done in the selecting of different positions, 

 etc., towards making plants hardy, and also that a large 

 class of plants which whilst tender in their juvenile 

 stage are perfectly hardy once above the "frost-line" and 

 with decent sized wood on them resist the severest of 

 winters with immunity. 



The three great families to which belong the great 

 majority of our hardy, deciduous, flowering shrubs are 

 the Eose family. Saxifrage and Honeysuckle families. 

 The first-named includes lieside Eoses all the Prunus 

 and Pyrus (in the broadest sense), Eubus, Cotoneaster, 

 Spiraea, etc., etc. The second includes the Deutzias, 

 Philadelphus, Hydrangeas, Eibes, etc.: the -third the 

 Viburnums, Diervillas and Loniceras. In China all the 

 large genera in these families run riot in number of 

 species and so many are new and undescribed that it is 

 impossible to discuss them satisfactorily. Further, so 

 great is the number in every instance that to deal with 

 them in even the briefest detail in these articles is abso- 

 lutely out of the question. The "Alfred Eehder" series 

 of articles have already given some idea of the wealth 

 of these different genera and later it is to be hoped that 

 the same vn-iter will deal with the individual merits of 

 these new species as they make themselves known in the 

 Arnold Arboretum. The members of these familiar 

 groups are all worth growing, all are good but some are 

 better than others. The mass of raw material belonging 





^■^^ 





COTONEASTEK DiELSIANA 



As Cultivated by Messrs. VeitcU. 



to the above and other prominent families m cultivation 

 in the Arnold Arboretum as the result of its recent en- 

 terprise in China is phenomenal and is calculated to in 

 a measure alter the whole aspect of shrubberies in the 

 parks and gardens of the Atlantic coast of the country. 

 The writer's time and space is exceedingly limited and 

 all he can do at the moment is to mention an odd plant 

 of proven merit here and there and leave the rest for 

 time to prove and others to expatiate upon. 



In China probably a couple of dozen or more Spiraeas 

 occur. Of these S. Thunbergii and S. japonica are well- 

 known and esteemed old friends. Three novelties of 

 proven merit and possibly superior as hardy shrubs to 

 any member of the family previously in cultivation are 

 Spiraea Henry i, S. Veitchii and S. Wilsoni. This trio 

 agree in having flat corymbs of white flowers but differ 

 one from another in habit and foliage. The first-named 

 fonns a sturdy bush, 3 to 5 ft. tall, with branches 

 straight and spreading and almost leathery leaves, shin- 

 ing above. S. Veitchii has erect and slightly arching 

 branches 6 to 8 ft. tall, large corymbs of flowers and 

 neat, ovate, smooth leaves. S. Wilsoni has soft, hairy 

 leaves and arching stems 4 to 6 ft. tall. The flat-trusses 

 of flowers are produced from the axils of the leaves along 

 the entire length of the past season's growth and when 

 in flower look like continuous sprays of the purest white, 

 the leaves being almost entirely hidden. In merit it is 

 difficult to decide which is best the writer's opinion in- 

 clining towards S. Veitchii. 



The Cotonea.sters are favorites with all on account 

 of their ornamental fruits. This family has been aug- 



