168 FRUITS. 



(85) Juniper Berries 



The fruit of Juniperus communis, Linn. (N.O. Coniferse). 



Each of the three fleshy bracts which enclose the seeds 

 exhibits the following structure : 



(1) An outer epidermis, consisting of a single row of brown 

 polygonal cells with thickened pitted walls. 



(2) A hypoderma, composed of two rows of brown collen- 

 chymatous cells, the radial walls of which are thickened, 

 particularly in the angles. 



(3) A tissue corresponding to a mesocarp ; this is built up of 

 irregular polygonal cells with intercellular spaces, and contains 

 large ovoid oil-glands. It is traversed by nbro-vascular bundles, 

 which, like those of most coniferous plants, exhibit tracheido* 

 bast tissue, and areolated cells and fibres. 



(4) A well-developed sclerenchymatous ring, composed of 

 seven or eight rows of rather large cells, with very thick, pitted 

 walls and narrow cavities, in many of which there is a single 

 prismatic crystal of calcium oxalate. That part of this tissue 

 which is directed towards the epidermis is bordered by a 

 single row of oval or elliptical cells with slightly lignified pitted 

 walls. Within the ring is a rather thick dense, brown layer of 

 collapsed cells. 



(5) An inner epidermis of elongated cells. 



The seed-coat consists of polygonal cells ; the endosperm 

 contains aleurone grains ; the cells of the embryo have very 

 thin walls. 



The diagnostic characters of powdered juniper berries are : 



(a) The sclerenchymatous cells with crystals of calcium 



oxalate. 



(b) The brown, pitted cells of the epidermis and the subjacent 



brown, collenchymatous layer. 



(c) The large parenchymatous cells of the pulp. 



(d} The areolated cells and fibres which, however, are not 

 numerous. 



