140 Rhodora [Jurv 
Who but a professional botanist, or one of the new school as regards 
nomenclature, will be able to recognize even common trees in the 
absence of synonymy? Even if we may admit that students fortu- 
nate enough to pursue their studies in the grounds of the Arnold 
Arboretum will not be disconcerted, in the presence of the familiar 
tree, to see Carya alba labeled Hicoria ovata, can we suppose that 
more than one student in a hundred, looking for the description of 
Ulmus racemosa wil, even after some diligence, recognize it as 
Ulmus Thomasi? 
But perhaps these remarks are beside the point. The question is, 
what will the student find in the book? The minutest, fullest details 
as to the characteristics in trunk, in branch, in twig, in leaf, in flower, 
in fruit, of every tree hitherto observed in all the length and breadth 
of North America, exclusive of Mexico; an account also of its cli- 
matal and geographical range; and last and best pen drawings to 
the number of six hundred and forty-four by the accurate hand of 
Charles Edward Faxon. * In them,” as the author says, and we are 
inclined to agree with him, * will be found the chief value of this 
manual." 
POLYGONUM EXSERTUM IN MASSACHUSETTS. — Polygonum exsertum 
Small has been collected several times along the Charles River in 
Boston, Massachusetts, associated with Aster subulatus Michx. 
After frost this species is rendered somewhat conspicuous by the 
reddening of the foliage and sepals. Where it grows in dry soil it is 
reduced in size and has smaller fruit. Mature achenes from a plant 
less than a foot high were only three millimeters long. Specimens 
examined: 4, S. Pease, no. 482, Sept. 27, 1900, (Hb. Pease); 4. 
H. Moore, no. 1539, Nov. 10, 1903, (Hb. Moore) ; Æ. H. Bartlett, 
Oct. 26, 1904, (Gray Hb. and Hb. Bartlett). —H. H. BARTLETT, 
Cambridge, Massachusetts. 
Vol. 7, no. 78, including pages 101 to 120 and plate 61, was issued 1 June, 1905. 
