652 SYSTEMATIC BOTANY. 



climates. Examples of the Gemra: — Carpinus, Corylus, Castanea, 

 Q,uereiis. There are nearly 300 species. 



Properties and Uses. — Most important on account of their 

 valuable timber. Many yield edible seeds, and some have 

 highly astringent barks and cnpules. 



Ca?-pinus. — C. Betulus, the Horn-beam, and C.americanus, are well known 

 for their timber, which is principally employed for making agricultural 

 implements, and for the cogs of mill wheels. 



Castanea. — C. vulgaris (vesca) is the Spanish Chestnut, which is much 

 cultivated for its timber, and for its nuts which are so well known for their 

 edible properties. They are principally imported from Spain, where they 

 are largely employed as an article of food by the agricultural classes. C. 

 americana, a native of the United States, also yields a much smaller, but 

 very sweet kind of Chestnut, which has been occasionally imported. 



Corylus Avellana, the common Hazel, is the origin of the most anciently 

 used and most extensively consumed of all our edible nuts. There are 

 several varieties of the Hazel, as the White, Red, and Jerusalem Filberts ; 

 the Great and Clustered Cobs ; the Red Smyrna, the Black Spanish, and the 

 Barcelona nuts, &c. The importation of these alone into this country is, on 

 an average, 150,000 bushels a year. The oil which is obtained from them by 

 expression is occasionally employed by artists and watchmakers. Good 

 charcoal is also obtained from the branches of the Hazel. 



Fagus.—F. sylvatica, the Common Beech, is well known for its timber. 

 The fruits (Beech-mast) form a food for pigs. The frait of F. ferritginea is 

 eaten in North America. The seeds of some species yield by expression a 

 fixed oil. 



Ostrya vulgaris (virginica) possesses a very hard wood, which in America 

 has been cailed in consequence Iron-wood. It is also termed Lever-wood 

 from its being used in making levers. 



Quercus.— The timber of several species of this genus is extensively em- 

 ployed for ship-building, and for other important purposes, as that of the 

 Q. Robur, the common British Oak, of which there are two varieties, whicb 

 by some are regarded as distinct species, called Q. pedunculata and Q. sessi- 

 flora ; that of the Q. Cerris, Turkey or Adriatic Oak ; of the Q. alba. 

 White Oak ; the Q. rubra, Red Oak ; the Black Oak (Q. (indoria) ; the Q. 

 Ilex; and the Live Oak (Q. virens), &c. Many Japane-e species also 

 yield valuable timber. The bark of several species is astringent, and largely 

 employed in tanning, &c. ; that of Quercus pedanculata is most esteemed. 

 This is also employed in medicine as an astringent and tonic. The fruits 

 (acoms) of this species and of the other species or varieties which are 

 natives of this country have been also generally recommended as food for 

 cattle, but recent experience would seem to show that they possess injurious 

 properties. The outer bark of Quercus Suber, the Cork Oak, constitutes 

 the cork of commerce. The bark obtained from the younger branches of 

 the same tree is imported into this country from Spain. It is usually 

 known as European Alcornoque Bark, and is employed for tanning purposes. 

 (See Boicdichia, p. 521.) The inner bark of older stems is also imported as 

 cork-tree bark, and similarly employed. Quercus JEgylops.—The acorn-cups 

 of this species are imported fi-om the Levant under the name of Valonia; 

 the dried half -matured acorns of the same plant are also imported under 

 the name of Camata ; and the very young ones as Camatina. These three 

 articles are very valuable for their "tanning properties. Quercus tinctoria, 

 the Black Oak, has already been noticed as a valuable timber tree. Its 

 bark is called Quercitron Bark, it is used for tanning, and in this country 

 its inner portion is also employed for dyeing yellow. The bark of this 

 species and that of Quercus alba is used in the United States for its astringent, 

 febrifugal, and tonic properties. The bark of Q. aquatica, a North American 

 species, and that of Q. Ilex, a South European species, is also employed by 

 tanners. Q. sinensis, a native of China, yields a dye. Quercus cocci/era, the 

 Kermes Oak, has its young branches attacked by a species of Coccus, by 

 which little reddish balls are formed upon their surfaces, which were 



