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extending further to the north than the species of that order. The most 
northern woody plant that is known is a kind of Willow, Salix arctica. They 
are found sparingly in Barbary, and there is a species of Willow even in 
Senegal. 
Properties. Valuable trees, either for their timber or for economical 
purposes ; the Willow, the Sallow, and the Poplar, being the representatives. 
Their bark is usually astringent, tonic, and stomachic ; that of Pop ulus 
tremuloides is known as a febrifuge in the United States ; the leaves of Salix 
herbacea, soaked in water, are employed in Iceland for tanning leather. 
Willow bai'k has been found by Davy to contain as much tanning principle as 
that of the Oak. Ed. P.J.l. 320. It has lately acquired a great reputation 
in France as a febrifuge. A crystallizable principle, called Salicine, has been 
obtained from Salix helix, which, according to Majendie, arrests the progress 
of a fever with the same power as sulphate of quinia. (See Journ. of the 
R. Inst. Oct. 1830, p. 177). 
GENERA. 
SaJix, L. 
Populus, L. 
Order CXXXVII. PLATANACE^E. The Plane Tribe. 
Platane/e, Lestiboudois according to Von Martins. Hort. Reg. Monacensis, p, 46. (1829.) 
Essential Character. — Flowers amentaceous, naked ; the sexes in distinct catkins. 
Stamens single, without any floral envelope, but with several small scales and appendages 
mixed among them ; anthers linear, 2-celled. Ovaries terminated by a thick style, having 
the stigmatic surface on one side ; ovules solitary, or two, one above the other, and sus- 
pended. Nuts, in consequence of mutual compression, clavate, with a persistent recurved 
style. Seeds solitary, or rarely in pairs, pendulous, elongated ; testa thick ; embryo long, 
taper, lying in the axis of fleshy albumen, with the radicle turned to the extremity next 
(opposite, A. Rich.) the hilum . — Trees or shrubs. Leaves alternate, palmate, or toothed, 
with scarious sheathing stipules. Catkins round, pendulous. 
Affinities. Formerly comprehended in the order called Amentacese, 
this is particularly known by its round heads of flowers, its 1 -celled ovary, 
containing 1 or 2 pendulous ovules, and its embryo lying in fleshy albu- 
men, by which it is distinguishable from both Betulacese, Myricaceae, and 
Artocarpeae, with all which, especially the latter, it has a close affinity. From 
the latter, indeed, it is chiefly known by the want of calyx, by the presence 
of albumen, and the absence of milk ; the habit of the two orders being much 
the same. Bartling combines Platanus with Artocarpeae, perhaps rightly. 
According to Gaertner, the radicle is next the hilum; according to Achille 
Richard {Diet. Class. 14. 23.), it is at the other extremity. 
Geography. Natives of Barbary, the Levant, and North America. 
Properties. Noble timber-trees, the wood of which is extremely valu- 
able; the bark of Platanus is remarkable for falling oflf in hard irregular 
patches, a circumstance which arises from the rigidity of its tissue, on account 
of which it is incapable of stretching as the wood beneath it increases in 
diameter. 
GENUS. 
Platanus, L. 
