1828 The Trees of Great Britain and Ireland 



POPULUS MARILANDICA 



Populus marilandica? Bosc, ex Poiret, in Lamarck, Encycl. Suppl. iv. 378 (181 6). 



Populus canadensis? Hartig, Naturges. Forstl. Culturpfl. 436 (1851) (not Michaux) ; Koehne, 



Deut. Dendr. 81 (1893); Schneider, Laubholzkunde, i. 7 (1904) (in part); Ascherson and 



Graebner, Syn. Mitteleurop. Fl. iv. 33 (1908) (in part). 

 Populus euxylon, Dode, in M(m. Soc. Hist. Nat. Autun, xviii. 41, 69 (1905). 



A tree of hybrid origin (cf. p. 181 5) less vigorous in growth and not attaining so 

 great a height as P. serotina, with branches wider apart and not regularly ascending. 

 Young branchlets glabrous, rounded. Buds small, viscid. Leaves (Plate 409, 

 Fig. 19) considerably earlier in unfolding than P. serotina, resembling in shape more 

 those of P. nigra than those .of the American parent ; when well developed about 

 4 in. long and 3 in. broad, rhomboid, cuneate at the base, tapering above into a 

 long acuminate apex ; glabrous ; serrations crenate, with incurved points, few and 

 wide apart on the cuneate base ; margin with scattered deciduous minute cilia ; 

 glands absent or one or two in number at the base ; petiole greenish. 



Pistillate catkins about i\ in. long ; axis slender, glabrous ; pedicels stout, 

 glabrous ; scales obovate, with irregular lobes ending in long filaments ; disc cup- 

 shaped, glabrous, undulate in margin ; stigmas sessile, yellowish, variable in number 

 two, three, or four each appresssd at the base to the summit of the glabrous 

 globose ovary, and dividing above into two erect arms. Fruiting catkins, fertilised 

 by other kinds of poplars, about 4 or 5 in. long ; capsules usually three-valved on 

 slender pedicels, ultimately immersed in the dense white silky wool of the seeds. 



This tree, which is always female, is not uncommon on the Continent, where it 

 is usually considered to be the pistillate form of the Canadian species. It is occasion- 

 ally met with in nurseries ; and should not be selected for planting either for orna- 

 ment or profit, as its masses of cottony catkins in late spring are disagreeable, and 

 its vigour of growth 8 is considerably inferior to that of P. serotina. 



The largest tree of this hybrid which we know in England is growing on the 

 lawn near the Palm House at Kew, and measures 90 ft. by 8 ft. 9 in. Its history 

 is unknown. On 5th July 1907 it was covered with downy seeds, a few of which 

 proved fertile ; and there is a young plant at Colesborne which was raised from them 

 by Miss F. Woolward. (A. H.) 



1 The description by Bosc is imperfect, and there is no authentic specimen in the Paris Herbarium. A specimen in the 

 Herbarium at Montpellier, from a tree cultivated in the garden there in 1833 under the name P. marilandica, and another in 

 the Kew Herbarium labelled P. marilandica, from a tree cultivated at Carlsruhe in 1845, were probably correctly named, and 

 may be accepted as the species meant by Bosc. The name P. marilandica may be objected to, as implying that the tree is a 

 native of Maryland ; but I prefer it to the later name of P. euxylon, Dode. 



2 Koehne's specimen of P. canadensis in the British Museum is identical with the Carlsruhe specimen. So far as I can 

 judge, the hybrid female poplar, which I consider to be P. marilandica, is the P. canadensis of German dendrologists. 

 Hartig's description is unmistakable, as he refers to its rhombic and scarcely ciliate leaves, with variable glands at the base, 

 and to its peculiar stigmas. Schneider states that P. canadensis is nearly always a female tree in cultivation, and figures 

 its rhombic leaves cuneate at the base. 



3 Simon-Louis, Catalogue, 1869, p. 72, speaking of this tree as P. canadensis, states that it is much less vigorous than the 

 peuplier de Virginie, meaning by the latter name P. serotina, Hartig. 



