TREES AND SHRUBS OF MEXICO.' 



By Paul C. Standley. 



22. FAGACEAE. Beech Family. 



The only representatives of this group native in Mexico are the oaks, which 

 belong to the largest genus of the family. The Old World chestnut ("castaiio," 

 the tree; " castana," the nut), Castanea satira Mill., is said to be cultivated 

 occasionally in Mexico, Oaxaca, and other states. 



1. QXJEBCUS L. Sp. PI. 994. 1753. 

 (Contributed by Dr. William Trelease.) 



Reference : A. De Candolle in DC. Prodr. 16 ^ 2-109. 1864. 



Trees or shrubs ; leaves alternate, deciduous or persistent, entire, toothed, 

 or lobed, the teeth and lobes often bristle-tipped; flowers monoecious, the 

 staminate ones in slender catkins ; stamens 6 to 12 ; pistillate flowers solitary 

 or in small clusters ; ovules 6, but only one maturing ; fruit an acorn, sub- 

 tended by an enlarged cup (involucre). 



The genus Qiiercus is very abundantly represented in Mexico ; indeed, no 

 other country has so large a number of s-pecies. In this region the oaks are 

 found chiefly in the mountains. In northern Mexico the species grow at 

 comparatively low altitudes, in the arid mountains, but they occur also at 

 high altitudes in the larger ranges, such as the Sierra Madre. In southei'n 

 Mexico oaks are almost confined to the high mountains, but a few species 

 occur near sea level. 



From an economic standpoint oaks ai"e very important. The wood is of 

 the highest quality, being very strong and durable, although these characters 

 vary in different species. It is used for an infinite variety of purposes, 

 especially where strength is desirable. It is highly valued for furniture and 

 for the interior finish of buildings, for ship building, wagons, railroad ties, 

 and many other purposes. As fuel, also, it is unsurpassed. No other group 

 of hardwood trees furnishes wood which is so widely used, in Mexico as well 

 as elsewhere. The bark, too, is important economically, being one of the 

 most widely used tanbarks. Several species of southern Europe have very 

 thick, corky bark, which furnishes the cork of commerce. 



The leaves of oak trees are often punctured by insects, and, as a result galls 

 ("manzanitas de encina") are formed. These are frequently of the most 

 beautiful and bizarre forms, and often brilliantly colored. They sometimes 

 contain as much as 60 or 70 per cent of tannic acid, and consequently they are 

 excellent for use in tanning leather. They are widely employed also for 

 making ink. 



Oaks are almost unsurpassed as shade trees in temperate regions. Because 

 of their tough wood they are seldom broken by wind. Their broad tops give 

 them a handsome appearance, and they are very long-lived. 



The acorns (" bellotas "), too, are of considerable economic importance, 

 although less so now than formerly.* In early times they were an important 



*The first installment of the Trees and Shrubs of Mexico, comprising the fami- 

 lies Gleicheniaceae to Betulaceae, was published as Part 1 of Volume 23, Con- 

 tributions from the U. S. National Herbarium, pp. 1-170, October 11, 1920. 



' See V. Havard, Bull. Torrey Club 22: 118-119. 1895. 



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