256 OAK 



\^ . /U Acorn smooth and polished ; leaves decidu- 



seep. 260.] '^^^^ hardly coriaceous, sinnate-lobed (Q. 



Robur). 



Quercus Robur, L. The Oak (Figs. 88, 89, 90). Large 

 spreading tree, with tortuous branches and obovate -oblong, 

 sinuately-lobed deciduous leaves. 



Male catkins pendent, 2 4 cm. long, breaking singly 

 from lower axils of shoots, but often in tufts, owing to 

 their breaking out from buds on twigs of the j)revious 

 year; flowers distant, each with a 6-partite, yellowish- 

 green, ciliate perianth, about 7 8 (4 12) sulphur-yellow 

 stamens. Female flowers in groups of 1 5 (or rarely up 

 to 10), inserted singly on the sides and apex of short or 

 long stalks, developed in the axils of the uppermost leaves 

 of the shoot. Each flower consisting of an ovoid 3-celled 

 ovary, invested by a reddish scaly velvet}^ cupule, and 

 surrounded by a minute perigone, and bearing three short, 

 spreading, broadening and round-ended red stigmas, some- 

 times squat and lobe-like. 



Acorns varying in form and size, 1 5 (often 2), on a 

 stiff, smooth or velvety stalk, 1 16 cm. long, or sessile in 

 the leaf axils; each about 2 3 cm. long (15 50 x 10 

 22 mm.), smooth and polished except at the puberulent 

 apex, longitudinally striate above, pale brown to leather- 

 tawny, and usually about twice as long as the cupule, 

 though sometimes much longer. Cupule scales densely 

 imbricate, triangular ovate, and suddenly pointed, very 

 numerous and small, velvety. The aborted seeds may be 

 found in the lower part of the shell, 



[Two principal varieties are distinguished, Q. peduncu- 

 lata (Fig. 88), with the acorns scattered and on evident 

 stalks, shoots glabrous, and the leaves glabrous and sub- 

 sessile ; and Q. sessilifiora (Fig. 89), with sessile and 



