216 POPULUS 



It belongs to the group of balsam poplars, with narrow leaves and angular 

 branches. 



P. MARILANDICA, Bosc. 



A large tree of spreading habit, with a corrugated, not burred, trunk ; 

 young shoots smooth. Leaves smooth, triangular-ovate, inclined to diamond 

 shape, nearly always widely tapering at the base, and with a long, slender 

 point ; 3 to 6 ins. long, three-fourths as wide ; shallowly round-toothed, teeth 

 incurved ; glands at base none to two ; stalks \\ to 3 ins. long, compressed. 

 Catkins always female, ultimately 4 to 6 ins. long ; stigmas two to four. 



A female hybrid between nigra and probably monilifera, bearing some 

 resemblance to P. serotina, but with longer points and more wedge-shaped 

 bases to the leaves, and not so erect and straight-growing a tree the sex 

 also is different. There is a fine tree on the lawn near the Water-lily House 

 at Kew, now 92 ft. high and 9 ft. 8 ins. in girth, no doubt planted there about 

 1843. Although handsome and imposing, it is not a perfect lawn tree, owing 

 to the litter its cottony seeds make on the ground at seeding-time. It is one 

 of the trees commonly known as " Canadian poplar," coming earlier into leaf 

 than P. serotina. The ordinary young shoots are round or very slightly 

 angled ; the vigorous ones ribbed. 



P. MONILIFERA, Alton. NECKLACE POPLAR. 

 (P. canadensis, Michaux ; P. deltoidea, Marshall (in. part).) 



A tree up to 100 ft. high ; young shoots rounded or slightly angled, green, 

 marked with long, light-coloured lenticels ; smooth. Leaves broadly heart- 

 shaped with a long, slenderly tapered apex, the cartilaginous margins set 

 with minute hairs and coarse, incurved, gland-tipped teeth, except at the base 

 and apex ; 3 to 5 ins. long and wide, smooth and bright green on both 

 surfaces, but darker above ; there are one or two pairs of glands at the base close 

 to the stalk ; stalk slender, smooth, 2^ to 3^ ins. long, flattened. Male catkins 

 densely flowered, 3 to 4 ins. long ; females twice as long, stigmas three or four. 



Native of Eastern N. America ; introduced in 1772. This tree with 

 P. angulata (g.v.) forms, in the opinion of some botanists, one species known 

 as P. deltoidea. In a broad sense this may be so, but the tree cultivated as 

 P. angulata is so distinct, that for garden purposes at least it is better to keep 

 it apart. The true P. monilifera is now exceedingly uncommon in Britain. 

 It hybridised many years ago with the Old World P. nigra, and has been 

 ousted from gardens by its more vigorous progeny. Its distinguishing marks 

 among black poplars are the ciliate margins and basal glands of the leaf, 

 which distinguish it from P. nigra ; and the round or only slightly angled 

 young shoots and coarse teeth of the proportionately broader leaf, which 

 distinguish it from P. angulata. 



P. NIGRA, Linnaus. BLACK POPLAR. 



A tree 100 ft. or more high, with a rugged trunk 5 or 6 ft. in diameter, 

 often forming large burrs on the surface ; young shoots smooth and round ; 

 buds glutinous. Leaves variable, broadly diamond-shaped, triangular or 

 ovate ; 2 to 4^ ins. long ; some are wider than they are long, others twice as 

 long as they are wide ; usually broadly tapered, sometimes straight across at 

 the base ; broad or slender pointed ; both surfaces green, quite smooth, the 

 cartilaginous margins regularly and shallowly round-toothed ; the teeth gland- 

 tipped ; stalk | to 2j ins. long, compressed to a knife-like form. Catkins 

 2 to 3 ins. long ; anthers deep red ; stigmas two in female flowers. 



Native of Europe. The true black poplar is not very frequently seen now, 



