148 



Garden and Forest. 



[Number 162. 



not very far from the town of Boerne. This passes, on the 

 one hand, into the mountain form of the west which 

 reaches the Guadaloupe Mountains of Texas, and on 

 the other into some of the small-leaved forms of the 

 variety nigrum of the Sugar Maple of northern Alabama 

 and of Tennessee. Considered in this way the Sugar Maple 

 is the most variable of our species, always within certain 

 limits, and the most widely distributed in its range, with 

 the exception only of the Negundo. The fact that the 

 Sugar Maple sometimes bears stipules, as was recorded by 

 Professor Gray many years ago (American Naturalist, vi., 

 767; vii., 422), is interesting, as the presence of these 

 organs has not been noticed in other Maple-trees, 

 although I find, sometimes, a minute caducous fringe of 

 white hairs on the enlarged base of the petioles of Negundo 

 which appear to be stipular in character. On some indi- 

 vidual trees of the Black Maple in Indiana and in central 

 Michigan these large and well-developed puberulous 

 foliaceous stipules are not uncommon. An illustration of 

 them appears on page of 149 this issue, made from speci- 

 mens for which I am indebted to Professor W. J. Seal. 

 These stipules are said to appear constantly, year after 

 year, on the same trees, but, in spite of this, can hardly be 

 depended on to distinguish the Black Maple, even as a 

 variety, as the individual trees which produce them are 

 confined to a few isolated localities, and they are not 

 present, so far as I have been able to examine them, on 

 trees in other parts of the country. 



The Black Maple in the extreme form, which appears 

 in central Michigan for example, is certainly a very 

 distinct tree. There it often has large, thin, three-lobed 

 leaves with broad shallow sinuses, the sides of the 

 basal sinus overlapping so that they seem almost peltate. 

 The leaves are villous or densely pubescent on the lower 

 surface, and sometimes furnished with large foliaceous 

 stipules. Their sides drop, as Professor Bailey has pointed 

 out {Botanical Gazette, xiii., 213), when they are fully grown, 

 like pieces of old limp cloth, giving to the trees a heavy 

 dull appearance which makes it easy to distinguish them 

 at a considerable distance. But this is the extreme- form, 

 and many intermediate forms occur which connect it with 

 our common eastern Sugar Maple and make it impossible 

 to look on the Black Maple as a species. 



The question of the correct specific name of the Sugar 

 Maple is not easily settled. Linnaeus bestowed upon the 

 Silver Maple the name of Acer saccharinum. The identity 

 of his Acer saccharinum is made clear by his description 

 published in the first edition of the "Species Plantarum" 

 and by the specimen upon which this description was 

 based preserved in his herbarium. Wangenheim, some 

 years later, when he described the true Sugar Maple, mis- 

 led probably by the vernacular name, transferred to this 

 tree the name of saccharinum, already appropriated to 

 another tree. Here began the error which has been con- 

 tinued by nearly all writers on our trees. The next name 

 given to the Sugar Maple, about which there can be no 

 question of identity, is Michaux's, Acer barbaium ("Fl. 

 Bor.-Am.," published in 1803). Marshall had published in 

 1785 his " Arbustum Americanum," in which Acer Sac- 

 charum is described, and it is held by some authors that this 

 is an older name of the Sugar Maple than the A. barbatum of 

 Michaux, and that being a different word from sacchari- 

 num, the Sugar Maple must be called Acer Saccharum. 

 A name, however, cannot be adopted as long as any 

 doubt exists as to the identity of the plant to which the 

 author applied it, and in this case it is not at all certain 

 what tree Marshall had in mind when he described his 

 Acer Saccharum. He enumerated six Maple-trees ; of the 

 identity of three of these, A. Pennsylvanicum (A. striatum, 

 Lam.), A. Negundo and A. Canadense (A. Pennsylvanicum, 

 L. ), there is no doubt. The others are A. glaucum, the 

 " Silver-leaved Maple," which he describes with flowers of 

 a deep red color, adding that " it is perhaps the A. rubrum of 

 Linnaeus." "The leaves," he says, "are five-lobed, some- 

 what toothed or deeply and irregularly sawed on their 



edges. They are pellucid green on their upper side and a 

 bright silver color on their under." This may be either the 

 Scarlet Maple or the Silver Maple, the color of the flowers 

 indicating the former; Acer rubrum, of the identity of this 

 there can be no question, as the flowers are described as 

 scarlet and pedicelate ; and A. Saccharum, by which 

 Marshall may have intended the Sugar Maple, the only 

 other species of his region which he had not described, 

 provided his Acer glaucum can be held to be the A. saccha- 

 rinum of Linnaeus ; but Marshall's description of his A. Sac- 

 charum, the only thing we have to depe*id on, cannot be made 

 to cover the Sugar Maple, as he says it flowers in the manner 

 of the Scarlet Maple, which seems to imply a species with 

 precocious flowers, either the Scarlet or the Silver Maple, 

 and as the flowers are said to be of an " herbaceous " color, 

 it is probably the latter, a view which is strengthened 

 by the name, Saccharum, probably a misprint for sac- 

 charinum, rather than the Latin substantive. But as the 

 identity of this plant cannot be satisfactorily determined, 

 for Marshall left no herbarium, the only safe way is to pass 

 over his name entirely and take up that of Michaux. If 

 this view is adopted, our Sugar Maple becomes Acer bar- 

 batum, Michaux, and its varieties Acer barbaium, var. nigrum 

 and var. Floridanum. 



67. Negundo aceroides. — There seems no sufficient reason 

 for retaining the genus Negundo, established by Moench, 

 who dismembered Linnaeus' genus Acer in doing so. 

 American authors, following Torrey and Gray, have 

 adopted Negundo, although Professor Gray as long ago as 

 the appearance of the second volume of his "Genera Il- 

 lustrate " suggested that Negundo was hardly distinct from 

 Acer. He continued to retain the genus, however, in later 

 publications, and in this was followed by Bentham and 

 Hooker in the "Genera Plantarum." Other and later au- 

 thors, including Maximowicz, Baillon, Koch and Pax, have 

 reunited Negundo with Acer, and I shall follow them in the 

 "Silva of North America," as Negundo only differs from 

 Acer in its pinnate or ternate leaves and in the linear anthers 

 of our species, and take up the Linnaean Acer Negundo for 

 our Box Elder. The California tree, which cannot be sepa- 

 rated specifically from the eastern form, will have to be 

 known then as Acer Negundo, var. Califomicum. Viewed 

 in this way, the genus Acer may be divided into two sec- 

 tions, as proposed by Maximowicz r 



1. Acer.— Flowers polygamous or dioecious, petalous or 

 apetalous. Leaves simple. 



2. Negundo. — Flowers dioecious, apetalous in the Ameri- 

 can species. Leaves pinnate or ternate. 



Charles S. Sargent. 



New or Little Known Plants. 



Viburnum dilatatum. 



THIS shrub is widely distributed and very common 

 in some parts of Japan, and is not rare in central 

 China. It is rather remarkable, therefore, that it has so 

 long escaped the attention of American and European 

 gardeners, as in the autumn, when its brilliant red fruit 

 covers the branches, it is, perhaps, the most ornamental 

 plant of the genus known in gardens, and by far the best 

 of the recent additions to the list of shrubs which can be 

 cultivated in the open ground in this climate. 



Viburnum dilatatum was introduced into England several 

 years ago by the Veitches, in whose nurseries, near 

 London, it flowered in 1875, their specimens supplying 

 the material from which the figure, published the next 

 year in the Botanical Magazine (t. 6215), was made. It 

 apparently did not fruit in England, and was soon lost 

 from cultivation. Seeds of this Viburnum were received 

 in 1880, at the Arnold Arboretum, from the Agricultural 

 College at Sapporo ; the plants raised from this seed 

 flowered a little in 1888, but it was not until two years 

 later that they produced fruit in profusion and displayed 

 their true ornamental value. 



