24 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



plantierensis, a tree not far off (see p. 17). From the latter 

 parent is derived the hairy twigs and the narrow columnar habit, 

 with ascending (not vertical) branches, which characterise 

 F. robusta. This is believed by M. Jouin to be the finest of all 

 the hybrids, and three trees on good soil in his nursery are at 

 18 years old about 90 feet in height, with stems 5^ to 6| feet 

 round at 5 feet from the ground. At Glasnevin, on poor, 

 shallow soil, in an exposed situation, there is a fine specimen of 

 F. robusta, which was obtained as a cutting in 1899. ^^ measures 

 about 46 feet in height and z ft. 4 ins. in girth. Its remark- 

 able straight stem, with very narrow ascending branches, is well 

 seen in Fig. 8 contrasting with the fastigiate habit of the much 

 older Lombardy poplar on the left. If this tree is found to bear 

 wind well, as it appears to do at Glasnevin, it may be of con- 

 siderable economic importance in Ireland, where the black 

 Italian poplar is broken to pieces by the constant prevailing 

 wind and heavy storms that are so common in most districts. 

 It would provide speedily excellent timber for box-making, as 

 the stem can be pruned readily to a considerable height before 

 the branches become too large. 



8. Fopulus Lloydti, Henry (see Fig. 9), is similar to F. robiista 

 in the pubescent branchlets and shape of the leaves, but is a 

 ■ female tree with flowers bearing 2 or 3 stigmas. Its origin is 

 obscure, but one of the parents is probably the English black 

 poplar (^F. nigra var. beiulifolia). The only large specimens that 

 we have seen are at Leaton Knolls, near Shrewsbury, the 

 residence of Major Lloyd, where three trees measured, in 19 10, 

 I20 feet high by 13 feet in girth, no feet by ti ft. 2 ins., and 

 98 feet by 10^ feet (see Fig. 9). Smaller trees have been noticed 

 near Cambridge, and at Turnham Green, London. 



Until lately all the hybrid poplars in cultivation had originated 

 as chance seedlings (the result of accidental crossing by wind- 

 pollination), which observant nurserymen or gardeners found 

 desirable to propagate on account of their vigour. The artificial 

 production of fast-growing hybrids is now being attempted. 

 The most interesting so far obtained by me is one named 

 Fopulus gerierosa, which was raised from seed produced in 1912 

 by fertilising a Fopulus angulata (?) tree at Kew with pollen 

 of the Pacific Coast (U.S.) balsam poplar {F. trichocarpa). Four 

 seedlings (Fig. 10) were obtained, which have made very rapid 

 growth and bear beautiful large leaves intermediate between the 



