56 Proceedings of the Roynl Trish Academy. 



This extremely rave tree, of which there is a living specimen in Kew 

 Gardens, was originally raised at Edinburgli Irom seed collected in 1851 by 

 Jelirey in British Columbia on Mount Baker, where tlie two species were 

 observed growing together by Engleniann in 1882.' I'siuja Jcp'rcyi has turned 

 up again, after an interval of sixty years. There is now growing in Mr. M. 

 Hornibrook's garden at Kuapton, Abbeyleix, a young tree, identical with 

 Jeffrey's plant, which was procured from Vancouver Island about four years 

 ago. It was dug up as a wild seedling a few inches high in the mountains 

 behind Cowichan Lake, where the two parent species probably intermix, as 

 one is a characteristic tree of the lower altitudes of Vancouver Island, while 

 the other is almost confined to the alpine zone. 



II. — HYRRin Larches. 



Hybrid trees, especially those of the first generation, are usually endowed 

 with remarkable vigour, so that they not only produce timber rapidly and in 

 great volume, but tliey also arc to a considerable degree immune from serious 

 attacks of in.sects or of fungoid disease. Hybridisation between the dill'erent 

 larclies is tlius a subject of economic importance, as the genus yields excellent 

 timber in a short term of yeara, provided the plantations remain in a healthy 

 state. The species most cultivated, L(irir airopaea, is unfortunately very 

 liable to disease. 



Each of tlie dozen known species of larch is confined to a distinct territory, 

 and natural hybrids have not been observed in the wild state. Three hybrid 

 larches liavc, however, originated spontaneously in cultivation; and crossing 

 has also been elfecled by artificial pollination. 



L Larix pendula. — One of tlic hybrid larclies, Larix 2)endula, Salisbury, 

 which puzzled botanists for over a liundred years, may now be briefly referred 

 to. Its liistory wa.s elucidated by I'rof. A. Henry* in 1915. It originated as 

 a single seedling about 1739 ; and the original tree, a first cross between 

 Lai'ix europaea and Larix americana, grew for many years at Mill Hill, near 

 London, being uliimately cut down in 1800. Tiiis tree attiucted much 

 attention on account of its extraordinary vigour. Lambert, tlie great authority 

 of his time on Conifers, said : " It was the finest and largest tree I liavc ever 



' It waa describc<I accurately as rcgnrds the leaves and twigs by A. Murray, in Proc. 

 R. Hort. Soc. iii, 20.5, fig. 1 (1S03), under the name Ahits FaUonuina, a minleading and 

 untenable designation, as .Jeffrey's plant i.s ijuite different from the alpine wild hemlock 

 spruce, previou-ily de.'<cribed u-ider this name by Balfour in 18ij3. The hybrid is some- 

 times also wr.ingly called Ahia Hoohtriana, A. Murray, which is a synonym no longer in 

 use, being a later name of the alpine wild species. 



'In "G-irdeners' Chronicle," 18th September, 1916, pp. 178-179, figs. 68-61, and 

 9th October. 1915, p. 234. 



