1840 The Trees of Great Britain and Ireland 



grows very rapidly in Canada, making a yearly growth of 6 to 10 ft. It is not killed 

 by the severe winters of Manitoba, and is useful for planting where wind-breaks are 

 desired quickly. 



P. yunnanensis, Dode, op. cit. 63 (1905), agrees in technical characters with P. 

 Sitnonii, from which it mainly differs in the brilliant red colour of the branchlets, 

 petioles, and midrib and nerves on the upper surface of the leaves. As in that species, 

 the glabrous branches have five projecting ribs, and the leaves are variable, both in size 

 and shape, and in the length of their petioles. The leaves on the long shoots of 

 young trees are narrowly elliptic or rhombic-elliptic, 3 to 4 in. long, i^to 2 in. wide, 

 glabrous, white beneath, cuspidate at the apex, cuneate at the base, closely crenulate 

 in margin, and with very short petioles, about \ in. long. On vigorous shoots they 

 are broadly ovate, 5 in. long, 3^ in. wide, with the cuspidate point directed to one 

 side ; petioles about 1 in. long. 



This poplar, which is very ornamental, is probably a sport or a geographical 

 form of P. Simonii; and was introduced from Yunnan, China, in 1906 by a cutting, 

 sent to Dr. Dode, which has been propagated by Chenault of Orleans. There are 

 young and thriving plants at Glasnevin, Casewick, Borde Hill, and Colesborne, the 

 leaves of which were still green on 15th November 1912. (A. H.) 



POPULUS TRISTIS 



Populus trisiis, Fischer, in Allg. Gartenzeit. ix. 402 (1841), and Bull. Sc. Acad. Imp. Petersb. ix. 



343 (1842); Koehne, Deut. Dend. 82 (1893); Schneider, Laubholzkun.de, i. 13 (1904); Dode, 



in Mint. Soc. Hist. Nat. Autun, xviii. 62 (1905); Ascherson and Graebner, Syn. Mitteleurop. 



Fl. iv. 49 (1908) ; Gombocz, in Math. Termes. Kozl. xxx. 98 (191 1). 

 (?) Populus balsami/era, 1 J. D. Hooker, Fl. Brit. India, v. 638 (1888) (not Linnaeus); Gamble, 



Indian Timbers, 691 (1902). 



A small tree. Branchlets as in P. candicans. Buds viscid, pubescent, ciliate, 

 often subtended by persistent ovate acuminate pubescent stipules. Leaves (Plate 

 410, Fig. 23), similar to those of P. candicans in colour, pubescence, and ciliated 

 margin ; but narrowly ovate, about 4 in. long and 2 in. broad, acuminate at the apex, 

 subcordate or rounded at the base. 2 Flowers and fruit of the cultivated plant 

 unknown. 



This species was described by Fischer from a cultivated tree at St. Petersburg, 

 supposed to have been introduced 3 from central Asia. Koehne identifies with P. 

 trisiis, the poplar which has been found by various travellers 4 in the north-west 



1 P. balsami/era is confined to North America, and is very distinct from any of the Asiatic species. 

 a Glands are only present at the base of large, well-developed leaves. 



3 P. tristis was mentioned as newly introduced into Germany, by Spath, Catalogue, No. 91, p. 96 (1893-1894). 



4 Thomson, who collected this poplar in the Zanskar district and other places near Leh in Ladak, describes it in IV. 

 Himalaya and Tibet, 180 (1852), as "a spreading tree, with large cordate leaves, which was first seen in Upper Kunawar, 

 and is common in all the Tibetan villages, up to the highest limit of tree cultivation." It was also collected "in N.-W. 

 India " by Dr. J. S. Stewart (specimens in the Edinburgh Herbarium) ; and in the Nubra valley in Tibet by Schlagintweit in 

 1856. It appears to be a pubescent form of P. ciliata, modified by a high and arid situation. The latter species, which, so 

 far as we know, is not in cultivation, has much larger, broad ovate-cordate densely ciliate leaves ; glabrous branchlets, buds, 

 and pistillate catkins ; disc of the flower lobed ; and grows at lower elevations in the Himalayas, from 4000 to 10,000 feet. 



