ROSACEA. 



437 



that country is not another natural cradle of the Cocoa-plura ; and 

 this question several contemporary writers have answered in the 

 affirmative.' 



A large number of the RosacecB are employed in industry, domestic 

 economy, medicine, and horticulture.- The property most widely 

 spread in the plants of this order is undoubtedly astringency, owing 

 to the abundance of tannin^ in their tissues. Accordingly we find that 

 the astringents most frequently employed in every-day medicine 

 belong to the Rosacea.'' This is the case with several Roses ; thus 

 the Eed or Provence Rose,^ and the Cabbage Rose'' (Fr., Roi^e a cent 

 feuilles, Rose pale') contain in their petals a free acid and a large 

 quantity of tannin.* The Agrimonies, though not so rich in this 

 substance, were formerly highly prized as astringents, especially 

 A. Eupatoria^ So with the x\lchemils, especially A. vulgaris^'' alpina^^ 



» B. H., Qen., 606, n. 1. 



2 RoSENTH., Syn. Plant. Biaphor., 943, 1159. 



■* The RosacecB have long been known as 

 one of the orders richest in tannin, and C. Sanio 

 had in 1863 made some observations as regards 

 the distribution of this principle in the tissues 

 of Fyrus, Prunus, and Amygdalus. A. 

 Te^cul made this question the subject of an 

 important work, read at the Academie des 

 Sciences on the loth of May, 18(i5 {Comptes 

 Rendus, Ix. 1035 ; Adavsonia, vii. 337), show- 

 ing that in certain species there is tannin 

 in all the tissues of the branches, epidermis, 

 layers of bark, fibrovascular bundles, and pith. 

 So in certain species of Ruhus and PoieniiUa, 

 the tannin is found everywhere in small quan- 

 tities, but is especially abundant in series of 

 special cells. These may form a continuous 

 layer on the surface of the liber region (Alche- 

 milla, Aceena), both internal and external. On 

 treating the medullary rays with iron salts, they 

 too may turn blue, and unite these concentric 

 layers of tannin-cells. In the pith of the Roses the 

 tannin cells are united into vertical rows, con- 

 nected by horizontal or oblique rows. In the 

 Brambles we find two types in which they are 

 distributed. Ruhus fruticostis, glandidosus, 

 laciniatus, &c., have longitudinal medullary 

 rows, connected transversely by elongated cells, 

 besides two unequal concentric layers of tannin- 

 cells in the bark; while in Ruhus strigosus, cory- 

 lifolius, &c., there are vertical rows in the 

 cortical parenchyma as well as in the pith, 

 usually without any transverse anastomoses in 

 the latter. In most of the Fragarlecu and San- 

 gmsorhem studied by the author, there are only 

 scattered cortical cells. In certain species of 

 Spirma there is tannin in the ci)iderniis, outside 



the liber, in the medullary rays, around the pith, 

 or even inside it. As regards the state of the 

 tannin in the Rosacea, Te^CUL distinguishes 

 between the case in which it takes a blue colour 

 directly it comes in contact with the iron salt, 

 without any need of exposure to the air, and 

 that in which, especially in the young organs, 

 the cells only become blue or black after being 

 exposed for twelve hours or upwards. The young 

 cells often only take a purplish or rusty tint. 

 Besides, pharmaceutists know that all the Rosa- 

 cea; do not strike blue with iron salts ; the tannin 

 of the Provence Rose especially strikes green. 



* GuiB., Drog. Simpl., ed. 4, iii. 266. 



^ Rosa gallica L., Spec, 704. — R. cuprea 

 Jacq., Fragm., t. 34. — R. pumila L. FIL, ex 

 Rau., Enum., 112 — R. remeusis DC, Fl. JV., 

 iv. n. 3708. — R. hiirgundica RcESS., iZo*., t. 4. — 

 R. oJJlcinaUs Red., lac. cit., 73. 



6 R. cenUfoUa L., Spec, 304. 



' The latter name is, according to Gtjibouet, 

 common to the Cabbage Rose and the Rose de 

 Pideaax. From it is m:ule the buttery extract 

 which comes from the south of France. 



^ From them are prepared syrups, extracts, 

 conserves, honey, &c. They enter into the com- 

 position of honey of Roses, pommade rosat, the 

 mixture catherelique de Lanfranc, itc. 



9 L., Spec, 643.— CEd. Fl. Dan., t. 588.— 

 GuiB., op. cit., 277. — H. Bn., Diet. Encycl. des 

 Sc Med., ii. 202 (Herb Agrimony, Francormier 

 or Fupaiolre des G-recs, des auciens). 



"* L., Spec, 178.— Peeeika, Flem.3Iat.Med., 

 ed. 4, ii. p. ii. 202.— Lindl., Fl. Med. 235.— H. 

 Bn., Diet. Encycl. des Sc. Med., ii. 560 (Lady's 

 Mantle, Pied-de-Uun, de-griffon, Sotdwiretle, &.C.). 



" L., Spec, 179, var. a. — A. argentea La.mk.., 

 Fl. Fr., iii. 303 {Pied-deUo:i satiiie). 



