CLASSIFICATION OF ANGIOSPERMS. 241 



flowers are violet-blue. The rhizome somewhat resembles that of 

 calamus, but is of a dark brown color and contains 25 per cent, of 

 acrid resins, a volatile oil, starch and tannin. 



Iris Uorentina, which yields the orris root of commerce (Fig. 

 69), is a plant cultivated in Middle and Southern Europe, and 

 closely resembles the above mentioned species. The rhizome 

 contains a volatile oil resembling that found in violets, and is used 

 in perfumery. Orris root is also obtained from Iris germanica 

 and /. pallida. The violet odor is developed on keeping the rhi- 

 zome a year or two. 



Crocus sativus, the orange-red stigmas of which have been used 

 in medicine since ancient times, is an autumnal-flowering plant. 

 The flowers are lilac-purple, somewhat like those of Colchicum, 

 and occur at the tip of a scape rising 15 to 20 centimeters above 

 ground. The leaves are linear and rise directly from a more or 

 less globular corm. The plant is cultivated in Spain and other 

 parts of Europe and in the United States as well. The stigmas 

 constitute the drug saffron (Crocus) which was formerly official, 

 and contain a coloring principle, i part of which will impart a 

 distinct yellow color to 100,000 parts of water. Saffron contains 

 a yellow glucoside, crocin, which is soluble in alcohol but not in 

 water, and is colored blue by sulphuric acid. The drug also con- 

 tains 7.5 to 10 per cent, of a volatile oil, which appears to be de- 

 rived from a coloring principle that resembles carotin; and the 

 bitter principle picro-crocin. 



e. JUNCACE^ OR RUSH FAMILY.— These are grass-like 

 marsh plants, which are distinguished by the fact that the flowers 

 are small, with 6-parted glumaceous perianth, and the fruit is a 

 loculicidally dehiscent capsule. The stems are mostly solid, slender, 

 usually arise in tufts from the rhizome and are characterized by 

 stellate parenchyma cells, among which are large intercellular 

 spaces, the latter also being characteristic of the leaves. The 

 rushes are principally found in cold and temperate regions. 



Several species of Juncus and Luzula have been used in medi- 

 cine, particularly in Europe. The seeds of Luzula campestris, 

 a common wood rush of the United States naturalized from 

 Europe, are edible. Soft rush {Juncus effusus) and Hard rush 

 (7. conglomeratus) are used in Japan in the manufacture of rush 



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