CORYLACEiE. 597 



3. Q. pedunculata, Willdenow. — Leaves sessile or on short petioles, obovate-oblong, 

 sinuated ; lobes entire or nearly blunt ; cup hemispherical ; gland oblong, obtuse, much 

 longer than the cup. 



Willdenow, Sp. PI. iv. 450 ; Lindley, Ft. Med. 291 ; Q. robur, Eng. 

 Bot. 1342; Stephenson and Churchill, iii. 151. 

 Common Names. — English Oak ; Common Oak. 



A large tree, found in most parts of Europe, and remarkable for its lon- 

 gevity. It was well known to the ancients, and was considered as sacred by 

 most of them. The medical properties of its bark are noticed by Galen and 

 Dioscorides, the latter of whom speaks of the astringent character of its inner 

 bark. This is employed in the same manner and for the same purposes as 

 that of the Q. alba. Another European species, Q. sessiliflora, has similar 

 properties. 



4. Q. infectoria, Olivier. — Leaves ovate-oblong, sinuate-dentate, very smooth, deci- 

 duous ; cup hemispherical, scaly ; gland long, obtuse, much longer than the cup. 



Olivier, Voyage, ii. 64, t. 14, 15; Willdenow, Sp. PI. iv.'436 ; Stephen- 

 son and Churchill, iii. 152 ; Lindley, Fl. Med. 291. 

 Common Names. — Gall Oak. 



This is a small tree or shrub peculiar to Asia Minor, and is celebrated 

 from its affording the Gall nuts of commerce. All the oaks bear these ex- 

 crescences, but except in this and a few other species, they are light and 

 spongy, and comparatively of little value. They are produced in the same 

 manner, namely, by the puncture of the buds by a fly to form a nidus for its 

 eggs. In this instance it is a species of Diplolepis that thus wounds the 

 plant. In consequence of the puncture, irritation is induced, the juices of 

 the tree flow to the part, and a semi- organized tumour is formed round the 

 larva, which, when it has attained maturity, perforates the gall and escapes. 



These excrescences were known to Hippocrates, and are described by 

 Dioscorides but as the fruit of the Oak. Galls are imported from the Medi- 

 terranean ports, but originally are derived from various places in Asia Minor. 

 There are several kinds or qualities recognised in commerce : the dark-co- 

 loured, which are the most valued, consist of the gall when it has attained its 

 full growth, but before it is pierced by the insect to escape; these are tumid, 

 and termed green, blue, or black, according to their tint; the light-coloured or 

 white galls are such as have been gathered after their perforation by the fly, 

 and are considered inferior, being less heavy and compact. The best qualities 

 are also known under the name of Aleppo Galls, and a secondary grade 

 under that of Smyrna. Of late years a third kind has appeared for sale, 

 imported from India. These, Dr. Royle states, are derived originally from 

 Bassorah, and further says, that when Dr. Falconer was travelling in the 

 Punjab, he was informed that galls were produced on the Balloot Oak, Q. 

 ballota. 



Galls are spherical, of various sizes, having numerous small tubercles 

 on their surface. The best are of a bluish or greenish colour externally, 

 and grayish within; hard, solid, with the exception of a small cavity in the 

 centre, formerly occupied by the insect. They are without odour, but have 

 a very astringent, bitter taste. They yield their properties both to water and 

 alcohol, but most readily to the former solvent. They contain much tannin 

 and gallic acid, with the usual constituents of vegetable bodies. Braconnot 

 has discovered another acid, which he calls Ellagic, but it is doubtful whe- 

 ther it is not a product, rather than an educt. 



From the quantity of Tannin and Gallic acid contained in Galls, they are 



