QUERCUS CRASSIPES—A MEXICAN OAK. 



79 



QUERCUS CRASSIPES—A MEXICAN OAK. 



By R. A. DiiMMER, F.R.H.S. 



This Mexican Oak was discovered by the illustrious Humboldt near 

 Santa Rosa and Ario, in Southern Mexico, at elevations of 6,000- 

 8,000 feet above sea level, where, as a small tree about 20 feet high, 

 with smooth greyish bark, it constitutes a member of the xerophilous 

 vegetation which occurs there. On his return to Europe, Humboldt, 

 in conjunction with Bonpland, described this species in 1813 ; but it 

 was twenty-six years before its introduction to British horticulture 

 was assured, when, in the Chiswick Garden of the Horticultural 

 Society, plants were raised from acorns collected by Hartweg 

 (one of the Society's collectors) near Real del Monte. The latter 

 also detected this rarity among Mexican Oaks at Tlalpugahua, and 

 subsequently Bourgeau had the good fortune to stumble across it 

 in the Valley of Mexico. 



Despite its distinctiveness, this Oak has been somewhat mis- 

 understood by even that great botanist Bentham, who confounded 

 it with the true Mexican Oak, Quercus mexicana ; and, curiously, that 

 careful French savant Gay was also misled in regarding it as the 

 Quercus confertijolia, another of the Mexican oaks. 



Though the seedlings alluded to were eventually distributed by 

 the Society to its members with no sparing hand, only one appears to 

 have survived the vicissitudes of the English climate, and that a fine 

 specimen in the grounds of Captain Tremayne at Carclew, Cornwall, 

 which is now 65 feet high, with a trunk-girth 5 feet from the ground 

 of 5 feet 5 inches. (Figs. 27, 28.) Its leaves fall in winter, but are apt 

 to persist for two years, and are clustered towards the extremities 

 of the twigs, being subtended by short stalks scarcely exceeding 

 one-sixth of an inch, and often even less. The current year's twigs 

 are roughly angled, dirty brown in colour, and are covered, like the 

 stalks, the midrib, and the lower leaf-surfaces with stellate hairs 

 plainly visible under a slight magnification. The leaf-blade is narrowly 

 oblong in general outline, blunt or with a slight awn-like bristle at 

 the apex, slightly rounded or obsoletely heart-shaped at the base, 

 the margin being faintly wavy and destitute of any teeth. 

 The leaves are firm and thinly leathery in consistency, and 

 with age the stellate hairs disappear from their upper greyish 

 green surfaces, though they invariably persist on the sunken midrib, 

 and especially so on the opposing ochre-green side, which is moreover 

 prominently net-veined, with its 10-19 paired lateral veins and their 

 attendant ramifications. From the head gardener I glean that he 



