June C, 190S 



HORTICULTURE 



749 



Notes from the Arnold Arboretum 



JJuriug tlie next weeks the Khododeudrous will be in 

 full bloom and the large group ou Hemlock Hill will 

 then be the most beautiful spot in the Arboretum. This 

 group is admirably situated with its background of 

 sombre Hemlock Spruces which not only afford a good 

 shelter, but also set off effectively the rich colors of the 

 flowering Rhododendrons. Besides those mentioned in 

 the issue of Ma}* 23, the earliest of the Catawbiense 

 hybrids have opened their flowers; these are Lady Ann- 

 strong with pink lilac flowers paler in the centre, 

 Atrosanguineum, rieli blood red, Prometheus, deep 

 crimson, Morion^ carmine and Coriaceum with white 

 flowers spotted greenish yellow, a low, free-flowering 

 shrub. The last named is apparently no Catawbiense 

 hybrid, but is so closely, related to Rhododendron cau- 

 casicum, tliat it may be considered a variety of that 

 species. Another Caucasian species is the beautiful R. 

 Smii-nowii with carmine pink flowers and very distinct 

 foliage, whitish tomeutose beneath; it has proved per- 

 fectly^ hardy, but appears to be more particular as to 

 the situation than other Rhododendrons; it apparently 

 prefers partial shade. 



Of the Rhododendrons of the Azalea-group the Ghent 

 hybrids are now very showy with their brilliant colors, 

 varying from orange and yellow to white, pink and 

 red, also R. rnolle with pink flowers and its hybrids. 

 A beatitiful native species is Rhododendron canescens 

 with, its pink, deliciously fragrant flowers; it is much 

 finer than 7?. riudiflonim with which it has been often 

 confounded and which has paler pinkish white flowers. 



Another noteworthy member of the Ericaceous fam- 

 ily now in bloom is EnHanthus campanulatus, a slen- 

 der shrub with nodding corymbs of rather small bell- 

 shaped flowers whitish suffused with pink and marked 

 conspicuously with red veins; it is not a very showy 

 shrub, but very attractive on account of the peculiar 

 coloring of the flowers. In autumn the foliage turns 

 beautifully red. EnHanthus japonicus has white flow- 

 ers and is a lower shrub of less ornamental value. 



In the last issue Lonicera Korolkovii was inadvertedly 

 omitted from the enumeration of the Honeysuckles: it 

 is certainly one of the finest species bearing light pink 

 flowers in great profusion ; the whole shrub has- on ac- 

 count of its slender branches -and small grayish green 

 foliage a very light and airy appearance enhanced by 

 the flowers being borne on slender stalks well above the 

 foliage. It is perfectly hardy and much to be recom- 

 mended. 



The earliest of all Diervillas the Diervilla praecox 

 mentioned in the issue of May 33 has given rise to early 

 flowering hybrids with showier flowers ; one of them is 

 Gracieux with blush flowers and another Conquerant 

 with carmine flowers. 



Deutzia Lcmoinci, one of the most beautiful Deutzias 

 is now well known and appreciated, but still prettier 

 are its hybrids with D. discolor purpurascens, which 

 have pinkish flowers at least in bud; to this group, 

 designated as D. myriantha, belong the varieties Boule 

 rose and Fleur de Pommier. 



Viburnum, Sargenti may be considered but little dif- 



ferent from the common Highbush Cranberry, but in 

 the flowering state it is certainly prettier on account of 

 the more profusely produced flower clusters with sterile 

 flowers of a purer white, their color enhanced by the 

 darker hue of the central fertile flowers caused by the 

 purple anthers, wliile the flowers of V. Opulus have a 

 yellowish tinge and yellow anthers : besides V. Sargenti 

 differs in the more compact habit and the darker and 

 firmer foliage. Unfortunately it lacks the most orna- 

 mental feature of V. Opulus, the large clusters of sear- 

 let fruits, which are produced but sparingly in V. Sar- 

 genti. A snowball form of this species which may be 

 looked for in time would be superior to the common 

 Snowball which is much troubled with aphids and there- 

 fore not so much planted as it used to be. Another 

 handsome Asiatic species is V. Wrightii with rather 

 large bright green foliage and conspicuous clusters of 

 white flowers followed by scarlet fruits in autumn. The 

 native 1'. pubescens is now very attractive covered all 

 over with white flower clusters ; it is a compact shrub 

 rarely exceeding five feet in height and turning deep 

 purple in fall. For larger shrubberies V. Lentago is a 

 very desirable shrub, it is now very handsome with its 

 numerous clusters of yellowish white flowers. 



Many species of Crataegus are now in bloom. The 

 large collection of American Hawthorns planted on 

 Peter's Hill, now numbering about five hundred differ- 

 ent species, will in time afford a splendid opportunity 

 to find out by actual comparison the ornamental qual- 

 ities of the different species and to make a selection of 

 the most desirable. Though the Hawthorns show in 

 their appearance a comparative uniformity, they vary 

 greatly in habit, spinosity, time of flowering, color of 

 fruits and their persistency on the tree. The earliest 

 as Crataegus Arnoldiana, C. arl-ansana, C. coccineoides 

 and the European C. nigra flowered about a fortnight 

 ago, while C. nitida with handsome lustrous foliage, the 

 graceful C. aprica and C. apt folia and many others are 

 now in bloom. Of foreign species may be mentioned be- 

 sides the well known varieties of C. Oxyaiantha the Si- 

 berian C. pinnaUfida to be recommended particularly for 

 its handsome deeply cut foliage, and the large red fruits 

 in autumn. 



British Horticulture 



A USEFUL REPORT 



For some years past valuable experimental work has 

 been carried on through the generosity of the Duke of 

 Bedford at his fruit farm in Woburn, Bedfordshire. 

 The Duke, in conjunction with Mr. Spencer V. Picker- 

 ing, F. R. S., has lately issued the eighth report, detail- 

 ing the results of the experiments with insecticides and 

 fungicides. It is explained that the aim has been to 

 substitute as far as possible exact quantitative measure- 

 ments for those more crude and tmsatisfactory methods 

 usually adopted, in which the impression produced on 

 the mind of the observer is the sole standard by which 

 the success or failure of an insecticide is gauged. The 

 principle adopted has been to ascertain what is the 

 action of an insecticide when it is applied under the 

 simplest and most perfect conditions possible, as in the 

 laboratory, and then to ascertain the results when it is 



