234 PLANT ORGANS OR PARTS OF PLANTS. 



parenchyma, which contains many aggregations of starch 

 grains and oil drops. 



By the drying of this loose middle layer the berries 

 acquire the marked wrinkling of their surfaces. The 

 tissue next within contains soft prosenchyma and small 

 spiral vessels, and within this, starch-free parenchyma 

 with large oil cells. The seed coat consists of a row of 

 small, yellow cells, on the inner walls of which there is 

 deposited a thickened porous layer; frequently there 

 are therein crystal rosettes of calcium oxalate. The 

 following dark brown-red thick tissue separates the layer 

 from the seed albumen, between which angular radially- 

 arranged cells, numerous oil spaces are disseminated. 

 The first are filled with trophoplasts in which there are 

 numerous small, angular starch grains, with few thick 

 nuclei. Other cells contain yellow grains of piperin; 

 the endosperm contains aleurone grains. 



CONIUM. HEMLOCK. 



** The full-grown fruit of Conium mactdatum, Linne 

 (nat. ord. Umbelliferce), gathered while yet green." 

 U. S. 



Though the fruit alone is official, we shall here con- 

 sider the leaves also. 



The biennial root of the conium plant bears an annual 

 stem, often over 2 m. high, round grooved, hollow, and 

 marked below with brownish-red spots. The plant 

 grows in waste places throughout the old world. It has 

 been naturalized in America. The plant grown in a hot, 

 dry climate is superior. 



Description. — The leaves are twice or thrice pinnat- 

 ifid compound, four to eight-paired, in general out- 

 line triangular, the lower ones often 40 cm. long, with 

 sheathing petioles, the upper smaller, almost sessile, and 

 less compound. The leaflets are deeply cleft, promi- 

 nently veined, the terminal leaflet larger, strongly 



