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named P. canadensis by the German dendrologists, but doubtfully 
of Moench. It is best, I think, to call it P. marilandica Bose., 
which, according to Henry, is its correct name, and under which 
it is known at Kew. It is always found as a female tree, and 
seems to be much less common in cultivation than P. serotina 
Hartig. The latter is invariably a male tree. — -A. B. Jackson. 
P. marilandica Bose. This tree is identical with specimens of 
this name dating from 1833. It is usually called P. canadensis $? 
in Germany, and it is P. canadensis Hartig (1851), which is a 
hybrid. It is not P. canadensis Michaux (1813), a name given to 
the native American species. See Trees of Great Britain , vil, p. 
1807. Rehder, in Journ. Arnold Arboretum , IV, iii, 161 (1923), 
argues that P. canadensis Moench (1785) is the oldest name for 
the hybrid between the American and European black poplars, 
and then uses this name as follows: 1. P. canadensis Moench, 
var. serotina is the Black Italian Poplar ( = P. serotina Hartig) ; 
2. P. canadensis Moench, var. marilandica is the hybrid, which I 
call P. marilandica. I consider this a needless complication and 
inaccurate, as no one knows what P. canadensis Moench really is ; 
and it is more convenient to call a tree by two names (P. mari- 
landica) than by three names P. canadensis var. marilandica. — A. 
Henry. 
P. [616]. Planted. “St. Ibbs,” St. Ippolyts, Herts., 
April 15 and Sept. 3, 1925. — J. E. Little. Mr. A. B. Jackson 
names this P. monilifera Ait., but Prof. A. Henry at first demur- 
red to the determination. Stamens, average of 10 flowers, 42 - 7, 
tree 60 ft. Like [618] near by, this tree is very different from 
any poplar I have gathered, both in the number of stamens, the 
large broad floral bracts, and the large, often cordate, acuminate 
leaves with ciliate margins. The catkins are large and flat 
(15 mm. expanded). — J. E. Little. Both foliage and male cat- 
kins do not differ essentially from native specimens at Kew 
with which I have compared it. This tree is very rare in culti- 
vation in this country, only two or three having been noted. It 
occurs wild, according to Henry, in Ontario, Quebec, New 
England, New York, and Pennsylvania. — A. B. Jackson. Prof. 
Henry wrote later : This is P. deltoidea Marshall, the American 
(northern) Black Poplar (= P. monilifera Ait.). It has the fim- 
briated scales of the species, and cannot be P. angidata. I with- 
draw my demur, as I have found the scales in the flower. 
Empetrum nigrum L. Moor above Sowden Beck, Jervaulx, 
N. Biding, Yorks, alt. circa 900 ft., June 3, 1925. All observed 
was, I believe, $ . — J. E. Little. See in Journ. Bot., June 1926, 
