564 A TEXT-BOOK OF BOTANY. 



which vary in color from crimson, brown, or yellow to nearly 

 white. The fine flavored but watery fruit of the wild red-rasp- 

 berry (R. sti'igosus) is sometimes substituted for the fruit of 

 Rubus Idccus (Fig. 243). 



Rosa gallica, which yields the red rose-petals, official in a num- 

 ber of the pharmacopoeias, is a native of Southern Europe and 

 is extensively cultivated. 



Rosa centifolia, which is now known only in cultivation, and 

 of which there are a large number of varieties, is distinguished 

 by its glandular leaflets, and its pale red or pink petals. The 

 cone-like collection of petals of the flower-bud is the part which is 

 used in medicine, but it is deficient in coloring principles and 

 fragrance as compared to Rosa gallica. 



Rosa damascena, the petals of which yield the oil of rose or 

 attar of rose, is extensively cultivated in Bulgaria and to some 

 extent in France and Germany. It flowers very profusely, and 

 the yield of oil is about 0.02 per cent. The oil consists of a crys- 

 tallizable hydrocarbon known as rose-camphor which is odorless, 

 and a liquid portion consisting of geraniol, 1-citronellol, 1-lina- 

 lool, citral, n-nonyllic aldehyde and phenyl ethyl alcohol. Similar 

 oils are obtained from other species of Rosa growing in Northern 

 Africa, Abyssinia and Northern India, as R. moschata, and 

 R, sempennrens. 



The fruits of wild brier (Rosa canina} naturalized from 

 Europe, as well as of other species of Rosa (R. pomifera and 

 R. rugosa), contain considerable malic and citric acids and fruit- 

 sugars, and are made into a confection by boiling with syrup. In 

 addition to the . fruit-ethers found in the common edible fruits 

 of this family and the volatile oil of rose, it should be mentioned 

 that oils containing salicylic acid are also present. A number of 

 species of Spiraea contain salicylic aldehyde and methyl salicylate. 



Quillaja Saponaria is a large tree having a thick bark and 

 hard wood. The leaves are oval, coriaceous, slightly dentate and 

 evergreen (Fig. 316). The flowers are monoecious or dioecious, 

 white, apetalous, and axillary in groups of one to four. The 

 ovary consists of 4 to 5 carpels and on ripening forms a star-like, 

 spreading group of follicles. The inner bark is the part used in 

 medicine. 



