350 



SYSTEMATIC BOTANY. 



sinuous ; radicle short, superior. Illustrative Genera : Juylans, L. ; 

 Cart/a, Nutt. 



Affinities, &c. A small but well-marked group, nearly related to Cupu- 

 liferse, but differing 1 in the solitary ovule and in the absence of a cupule. 

 From the resinous juices and pinnate leaves, they have been regarded as 

 allied to Terebinthaceoe ; but the latter have petals, a free ovary, and 

 curved ovule. The Walnut (Jur/lans reyia) is a well-known example of 

 the Order. The wood of this, as well as of J. nigra, is valued by carpen- 

 ters. The nuts of J. cimrea are called Butter-nuts in Canada. Carya 

 alba, the Hickory of North America, has tough, elastic wood and an 

 edible nut, as also has C. oliviformis. 



:. THE OAK ORDEB. 

 Coli. Quernales, Hook. 



Diagnosis. Trees or shrubs with alternate simple feather-veined leaves 

 and deciduous stipules ; monoacious flowers, the barren in catkins or 

 clustered, the fertile solitary or clustered and furnished with an involucre 

 which forms a cup or covering to the flowers (fig. 439) ; (j* stamens 5-20, 

 inserted at the base of scales or of a membranous perianth ; $ ovary 

 crowned by the rudimentary teeth of an adherent calyx, 3- or more celled 



Fig. 439. 



Fig. 440. 



Fig. 439. Quercu* : a, vertical section of female flower ; 6, cross section. 

 Fig. 440. Opened involucrejwith two flowers of Castaiiea. 



(fig. 440) ; stigmas nearly sessile ; ovules solitary, or 2 in a cell ; fruit a 

 nut, 1-celled by abortion, woody or leathery, more or less enveloped by 

 the involucre (cupule), containing 1 or 2 seeds (the rest being abortive), 

 destitute of perisperm j cotyledons large and fleshy j radicle minute, supe- 

 rior. 



ILLUSTRATIVE GENERA. 



Tribe 1. EU-CUPULIFERJE. Male flowers with a perianth, female perianth 

 Q-lobed; ovary 2-6-celled ; fruit of l-3-seeded nuts, in a hard or thick 

 cupule or involucre. Quercus, L. ; Castanea, Gcertn. ; Fagus, L. 



Tribe 2. CORYLACEJE. Male flowers with a single scale, female perianth 

 irregularly lobed ; ovary \-celled with 2 pendulous ovules ; fruit a nut 

 in afoliaceous involucre. Carpinus, L. j Corylus, Z. 



