THE BLACK POPLARS. 2$ 



Another tree, a cutting of the last, planted in 1870, was 140 feet 

 high by 15 feet in girth. P. Eugenei \hx\vQS in sandy soil at Kew, 

 where, of eight trees 24 years planted, the two largest, in 191 2, 

 measured 90 feet by 5 ft. i in. and 84 feet by 4 ft. 5 ins., 

 whilst the others ranged from 50 to 60 feet in height and 

 2 ft. 4 ins. to 3 ft. 5 ins. in girth. All preserve the narrow 

 pyramidal form (see Fig. 7). 



5. Populus Henryana, Dode (see Fig. 3), is one of the hybrids 

 with a branching habit, recalling that of F. monilifera. It is a 

 staminate tree, with leaves cuneate at the broad base. It is 

 very rare, and is probably of no particular vigour, but forms a 

 picturesque tree when old, as shown in the illustration, which 

 represents a fine specimen at White Knights, about 100 feet in 

 height and 14 feet in girth. The origin of this hybrid is 

 unknown. 



6. Populus marilandica, Bosc. This hybrid, like the preceding 

 five, has glabrous twigs, but the leaves in shape strongly 

 resemble /'. tiigra, from which it may be distinguished by the 

 presence of glands at the base and stray cilia on the margin of 

 the blade, and by the placentas and stigmas being variable, 2, 3, 

 or even 4 in number. This originated early in the nineteenth 

 century, and specimens so named from trees at Montpellier in 

 1833, and Carlsruhe in 1845, can be seen in herbaria. It is 

 always female, and has been erroneously identified by Hartig, 

 Koehne, Schneider, etc., with P. canadensis, Michaux, which is 

 one of the later names of the true American species. It is not 

 very vigorous, but a tree at Kew near the palm-house measures 

 90 feet high by 8 feet in girth. 



The two remaining hybrids (7 and S) have as one parent 

 Populus nigra var. beiulifolia, and in consequence their twigs are 

 covered, like it, with pubescence. In the preceding six hybrids, 

 the corresponding parent is the glabrous Populus tiigra, either in 

 its ordinary spreading form (var. typica) or in its fastigiate sport 

 (Lombardy poplar), and in consequence the twigs are glabrous. 



7. Populus robusta, Schneider (see Fig. 8). This was found 

 in 1895 in Simon-Louis' nursery near Metz, and during my visit 

 there in 19 13 I was shown the spot where the seedling was 

 picked up, about 20 feet distant from an old tree of Populus 

 anguata (about 80 feet high and 8 feet round). This bears 

 female flowers regularly ; and one of these, giving origin to the 

 seedling, must have been pollinated by the pollen of Populus 



