INCOMPLETE. 351 



. &c. Related to the Urticacese, but differing in the inferior, 

 many-celed ovary, and in the character of the fruits and seeds. From 

 Betulacese and Salicaceae, to which they are closely allied, they are sepa- 

 rated by the inferior position of the ovary. Brongniart indicates an 

 affinity with Pomaceae. Some authors separate the Oorylacese from 

 Cupuiiferae by reason of the achlamydeous male flowers and of the leafy 

 cupule of the female flowers of the former. In the Flazel (Corylus) at 

 the time of flowering the female flower consists of ovary begirt with an 

 adherent and scarcely perceptible calyx, and surmounted by two styles. 

 The cells of the ovary with their ovules do not appear for months after- 

 wards. The pollen is generally roundish or ovoid, with three plaits. The 

 eupule of the Oak seems to be the dilated concave end of a branch ; the 

 scales represent stipules. The maturation of the acorns takes place in 

 one year, or not until the second year after formation. The rind of an 

 acorn, chestnut, or beech-nut, and the shell of a filbert, are the hardened 

 and consolidated calyx-tube and ovary enclosing the (by abortion) soli- 

 tary seed. 



Distribution. A large group, the members of which are for the most 

 part natives of forests of temperate climates. 



Qualities and Uses. Timber-trees of great importance, some also having 

 edible fruits ; the bark and other parts more or less astringent. Quercm, 

 a very extensive genus, includes Q. Robur, British Oak, of which there 

 are two varieties, Q. sessiliflora, Durmast, and Q. pednnculata. Q. Siiber 

 furnishes cork, which is a thickening of the cellular layers of the outer 

 bark, which increase year by year, and are separated by deep-coloured 

 periderm-cells. The outer rough cork is called the male cork ; the inner 

 cork-cells near the liber are much finer and constitute what is called the 

 female cork. The cork is removed about once in seven years. Q. dEyilops 

 has large rough cuptiles, extensively used by dyers under the name of 

 Yalonia ; Q. cocci/era is the Kermes Oak ; Q. tinctoria furnishes Quer- 

 citron Bark ; Nut-galls are produced by the attacks of an insect on Q. in- 

 fectoria j Q. Ilex is the Holm Oak, or Evergreen Oak of our shrubberies. 

 Between 200 and 300 species of Quercus exist, some of which have edible 

 fruits. The leaves of Q. mannifera exude a sugary substance ; Corylus 

 avellana is the Filbert or Hazel ; Castanea vesca the Sweet Chestnut; C. 

 americana produces a smaller nut ; Fayus xylvatica, the common Beech, 

 has a valuable hard wood, as also Carpinm Hetulus, the Hornbeam ; and 

 Ostrya viryinica is called Iron-wood in North America. Oil is obtained 

 by pressure from the seeds of the Beech and the Hazel ; the Nut-oil of 

 the latter is largely used by painters. 



GARRYACEJS. A small Order of shrubs of North-west America, and 

 having amentaceous inflorescence, unisexual flowers, a 2-4-parted perianth, 

 definite stamens, and a 1-3-celled inferior ovary, with 2 pendulous ovules ; 

 seeds with a minute embryo in abundant perisperm. They differ from 

 Hamamelidaceae in their apetalous flowers, definite stamens, and baccate 

 fruit. By Bentham and Hooker they are included under Cornaceae. 

 They are also allied to Gunnera in Araliacese. 



