October 9, 1909 



HORTICULTURE 



4S)7 



Notes from the Arnold Arboretum 



Among the genera new to cultivation one of the most 

 beautiful is Dipelta belonging to the Caprifoliaeeae and 

 allied to Diervilla. Dipelta forihunda is a shrub with 

 opposite short-stalked leaves oblong or elliptic-oblong in 

 outline, long-pointed and from two to three inches long. 

 The white and pinkish, campanulate flowers are about 

 one and one-third of an inch long and produced in 

 great profusion along last j'ear branches in tliree to 

 seven-flowered clusters. The rather conspicuous dry 

 fruit is with its large wings almost orbicular in outline 

 and measures about three-quarters of an inch in diam- 

 eter. A second species, Dipelta ventricosa, is similar to 

 the preceding, but the flowers are wider and purplish red 

 outside, while inside they are white with orange mark- 

 ings. 



A very interesting new genus belonging to the 

 Hamamelidaceae is Sinoiuilsonia named in honor of Mr. 

 E. H. AVilson, one of the most successful collectors in the 

 history of plant introductions. Its only species is S. 

 Henryi, a small deciduous-leaved tree from ten to thirty 

 feet high. The alternate short-stalked leaves are obovate 

 to broadly elliptic, finely toothed at the margin, from 

 three to six inches long and slightly stellate-pubescent 

 on both sides. The small rather insignificant flowers 

 are dioecious and are disposed in slender upright 

 racemes about four inches long; this, however, re- 

 fers only to the pistillate plants, the staminate ones 

 being still unknown. The fruit is similar to that of 

 our Witch hazel, but smaller. The tree will probably be 

 hardy here. 



To the same family as the preceding belongs Sycopsis 

 sinensis, a small evergreen tree from fifteen to twenty 

 feet high. The alternate stalked leaves are oblong to 

 ovate-lanceolate in outline, pointed, entire or slightly 

 and sparingly toothed and from two to three inches long. 

 The dioecious flowers appear in small axillary stalked 

 clusters, the staminate ones being rather conspicuous 

 owing to their numerous exserted stamens. The fruit 

 is a capsule similar to that of the preceding species. The 

 tree will probably not be hardy in this region. 



A new genus of climbing shrubs is Clematoclethra be- 

 longing to the Dilleniaceae and related to Actinidia. 

 Several species of it are known from China ; tliey are all 

 high climbing shrubs with deciduous, alternate and slen- 

 der-stalked leaves ovate to lanceolate in outline, pointed, 

 finely toothed at the margin and from three to five inches 

 long; they resemble somewhat those of Clethra. The 

 white cup-shaped flowers are rather small and appear in 

 few-flowered stalked clusters in the axils of the leaves. 

 The berry-like fruit is scarcely more than half an inch 

 long. The Clematoclethras resemble in their general 

 appearance Actinidia and are probably of the same 

 hardiness. 



Evodia rutaecarpa is a large shmb or small tree at- 

 taining to thirty feet in height and resembles Phelloden- 

 dron in foliage, but dift'ers markedly from that genus in 

 its capsular fruits. It is also related to Xanthoxylum 

 but easily distinguished by the opposite, not alternate, 

 leaves which exhale when bruised a pungent odor. The 

 large pinnate leaves are with the stalk eight to twelve 

 inches long and are composed of seven or nine ovate to 

 oblong, pointed leaflets. The insignificant flowers ap- 

 pear in large terminal corymbs from four to six inches 

 across and are followed by the small capsular fruits dis- 

 closing when opening glossy dark brown or nearly black 



seeds. The tree will probably be as hardy as Phelloden- 

 dron. 



A very interesting genus is Dipteronia with only one 

 species, D. sinensis, closely related to Acer and forming 

 with that genus the family of Aceraceae. It is a small 

 tree from fifteen to twenty feet high with large pinnate 

 leaves composed of ovate coarsely toothed leaflets and 

 with small white flowers in large conspicuous terminal 

 panicles. The fruits consist like those of Acer of two 

 winged seeds, but these are surrounded equally on all 

 sides bv the broad wing and oval in outline. 



What 1909 Has Taught Us 

 About Peonies 



THE GLUT AND THE MIXTURES 



There is a glut of common varieties. The rushing 

 into the growing of peonies by every small nursery — ■ 

 the seedsmen — the cheap rose grower who caters for rose 

 buyers at twelve for a dollar — and the amateurs who 

 sign themselves as specialists — has brought it about. 



There will be no further use in America's going to 

 Holland to get peonies, or even to get them mixed to 

 suit. How can growers who delegate the work to hired 

 help ever know how badly the roots are mixed? And 

 can seedsmen and such ever keep them straight? The 

 past year has proven to me that eternal vigilance is the 

 price of rows of true peonies. A small grower who 

 does it well, will have his hands full with only a small 

 patch. 



NEW VARIETIES OF DISTINCTION 



The newer varieties which have been noticeable, are 

 all of the wide petal flowers. The blooms are extra large 

 and the petals are wide and incurved, giving the flower 

 a grand effect. Such varieties as Eosa Bonheur — 

 Therese, Gemiaine Bigot, James Kelway, my seedling 

 Georgiana Shaylor and the latest Lady Alexandra Duff 

 are this class. There are no better peonies in existence, 

 unless some of the newer introductions, such as LeCygne, 

 Soulange, Mignon, Francois Eosseau and Mme. Jules 

 Dessert should develop in the next year or so to be 

 better. These latter peonies are the latest French va- 

 rieties, and I am impatiently waiting to see what they 

 will become when well established. 



DEMAND FOR COLLECTION 



There is a growing demand for collections of peonies 

 which are really of the first-class. Buyers are getting 

 to be very critical. The grower who succeeds must be 

 progressive, and be able to furnish the best. He can- 

 not hope to meet this demand by making up ready-made 

 collections. Such collections are very generally made 

 up around one or two first-class varieties, and the rest 

 as fillers. Xo matter if they are called the Challenge of 

 the World or Un approached by Anything in existence. 

 Another thing noticeable is that the best peonies are 

 not plentiful. It is hard to keep a stock ahead of such 

 varieties as Therese and Eosa Bonheur. The very dry 

 weather has caused some rust on certain varieties. The 

 best way to do in this case is to cut off the stalks and 

 burn them. 



THE OUTLOOK 



The outlook for peonies is good enough. The glutting 



