383 
“ Trees and Shrubs” includes not only North American woody 
plants, but new or little known species from other regions, especially 
those likely to flourish out of doors in the United rage and 
urope, and others possessing particular commercial valu 
‘The editor has secured the collaboration of several epecialisis 
the chief of whom, from his numerous contributions, is 3 
Rehder, who is responsible for the text accompanying 85 out of the 
175 5 plates so far published. 
Sargent supplies the text to 70 plates, 42 of which are 
given 46 = ataegus, all but one being new species. This genus, 
which appears to be so extraordinarily variable in North America, 
has during ‘the last 15 years received a great deal of attention from 
American te oi feet y from Mr. . Beadle, Mr. 
Ashe and Prof. Sargent. Previous to 1896 the total 
number of iecies ‘feaceadly recognised amounted to less than ‘70, 
indluding 14 from North America. Si ince, and chiefly during the 
last few years, new species have been createl in hundreds, the 
precise number of American species described since 1896 being 922. 
Writing on “ The soa ee in North America ” (Journal of 
Botany, 1907, p. 289) Prof. Sargent does not support the theory 
_ that the many forms of the genus in North America are hybrids of 
recent origin. Many seedlings have been raised in the Arnold 
Arboretum and they do not show the tendencies to variation usually 
found in the offspring of recent hybrids. They do not vary in 
foliage, flowers or fruit, and Prof. Sargent has never seen what 
seemed to him to be a hy brid Crataegus. He finds that the time of 
flowering, number of stamens, colour of anthers, time of ripening 
and the nature of the fruit, and the form of the nutlets, are constant 
and can i" depended on as es characters. 
t t. 51 a figure is given of the Chinese Tulip Tree which the 
editor desaisben under the name of Liriodendron chinense. It was 
formerly regarded as a variety of L. Tulipifera, but it differs in the 
flowers, which are not more than half as large, with much narrower 
petals, and _in the elongated fruit-eone and the shape of the inner 
ls. This plant is especially interesting since it forms another 
connecting link between the floras of Eastern North America 
and Eastern Asia, The genus as now understood contains only 
2 species, one from each of the regions named. It is shown that 
eee eer on was widely spread over — America and 
ur 
Steal only 3 species (or 4 aster, s held t 
distinct from H. japonica) were known: H. oirginsands L, pote: is 
widely distributed in Eastern North America, H. japonica, Sieb. 
& Zuce., from Japan and the Province of Kiangsi, Giaitend China 
a) mollis, Oliv., from Central China. In the last part o 
“ Trees and Shrubs” (t. 136, p. 137) Prof. Sargent figures and 
specimen with fragmentary flowers from Soe probably belongs” 
to the same species. 
Ulmus japonica, Sargent (t. 101) is based on U, campestris var. 
japonica, Rehder (var. laevis, Fr. Schmidt). It resembles both 
U, americana, Linn, and U. campestris, Linn, 
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