RHAMNACEZ. 
SILVA OF NORTH AMERICA. 
39 
tinged with red, the thin sapwood being lighter colored. The specific gravity of the absolutely dry 
wood is 0.5836, a cubic foot weighing 36.37 pounds. 
The bark of Rhamnus Purshiana possesses the drastic properties found in that of the other 
species of the genus. 
It is a popular domestic remedy in the region where the plant grows, and under 
the name of Cascara Sagrada has been admitted into the American materia medica.! 
In the south Rhamnus Purshiana gradually passes into a variety” in which the branchlets and 
leaves, especially on their lower surface, are densely coated with thick white tomentum. This is a low 
spreading shrub, and the only form in southern California, Arizona, and Mexico, occurring also occa- 
sionally in central California. 
Lthamnus Purshiana was discovered in Montana on the banks of a tributary of the Columbia in 
1805 or 1806, by the members of the first North American transcontinental exploring expedition under 
command of Lewis and Clark. 
naturalist Eschscholtz.* 
precariously hardy in New England. 
It was first noticed on the coast of California in 1816 by the Russian 
Rhamnus Purshiana has been cultivated in the Arnold Arboretum since the 
year 1873, and is sometimes found in its different forms in European botanic gardens. 
It is only 
The specific name given to it by De Candolle commemorates the botanical labors of Frederick 
Pursh,° who first described this plant. 
1 Cascara Sagrada has proved valuable as a tonic laxative, and 
is now generally used in the United States and in some European 
countries, the annual consumption of the crude drug being esti- 
mated at 500,000 pounds. It is employed in decoctions, tinctures, 
fluid extracts, and cordials (Stillé & Maisch, Nat. Dispens. ed. 2, 
659.— Johnson, Man. Med. Bot. N. Am. 122.— Maisch, Organic 
Mat. Med. 194. — Parke, Davis & Co. Organic Mat. Med. ed. 2, 
44, — Pharmacology of the Newer Materia Medica, Part 3, January, 
1890, f. 1-3, where will be found a detailed account of the drug 
and its action). 
2 Rhamnus Purshiana, var. tomentella, Mary K. Brandegee, Zoé, 
i. 244. 
R. tomentella, Bentham, Pl. Hartweg. 303. — Seemann, Bot. Her- 
ald, 275. — Walpers, Ann. ii. 267. 
Frangula Californica, var. tomentella, Gray, Pl. Wright. ii. 28 
(Smithsonian Contrib. vi.).— Torrey, Pacific R. R. Rep. iv. 74; 
vil. 9. 
R. Californica, var. tomentella, Brewer & Watson, Bot. Cal. i. 
101. — Sargent, Forest Trees N. Am. 10th Census U.S. ix. 41.— 
Trelease, Trans. St. Louis Acad. v. 367.— H. H. Rusby, Druggists’ 
Bull. iv. 338, f. 4, 5, 10. 
R. Californica, Hemsley, Bot. Biol. Am. Cent. i. 197. 
8 Broad-leaved forms of this variety, with the same hoary tomen- 
tum, collected by Brandegee in Lake and Colusa counties, serve to 
unite it with the broad-leaved glabrous form of the northwest-coast 
region. 
4 Johann Friedrich (Iwan Iwanowitsch) Eschscholtz (1793-1831) 
was born in Dorpat. He accompanied Captain Kotzebue as sur- 
geon and naturalist in the ship Ruric, on the voyage of discovery 
in the Pacific Ocean which he made between 1815 and 1818, under 
the auspices of Count Romanzoff, passing the month of September, 
1816, in the neighborhood of the Bay of San Francisco, where he 
discovered a number of plants afterwards described by him in the 
Memoirs of the Academy of St. Petersburg, and in Linnea by his 
companion, the botanist and poet, Adelbert von Chamisso, the au- 
thor of Peter Schlemihl. 
appointed professor of medicine and director of the Museum of 
On his return to Russia Eschscholtz was 
Zoology in the University of Dorpat, to which he presented his col- 
lection. In 1823 he accompanied Kotzebue in a second voyage of 
discovery, publishing its scientific results in London in 1826. Esch- 
scholtz was the author of numerous works upon zoology, including 
the description of the animals in the recital of Kotzebue’s second 
voyage. Lschscholtzia, the so-called California Poppy, now one of 
the most familiar and beautiful of garden annuals, commemorates 
his connection with the botany of the Pacific coast. 
5 In 1838 Rafinesque found the tree which he described as Per- 
fonon laurifolium in Bartram’s Botanic Garden near Philadelphia. 
It was a native of the mountains of Oregon, and was then twenty 
feet high. The description leaves little doubt of the identity of 
this plant with Rhamnus Purshiana. Its size, when Rafinesque saw 
it, would indicate that it had been raised from seed brought back 
by Lewis and Clark from the valley of the Columbia River. (Gar- 
den and Forest, iv. 76.) 
6 Frederick Pursh (1774-1820) was born in Tobolsk, in Siberia, of 
German parentage. He was educated in Dresden, and emigrated 
to America in 1799, establishing himself in Philadelphia, where for 
three years he served as gardener to William Hamilton, whose 
gardens were at that time the richest and most famous in America. 
Pursh then devoted several years to traveling in eastern North 
America and the West Indies for the purpose of studying the plants 
of the country, the object, he tells us, that brought him to America. 
In 1812 he carried his collections to London, where two years later 
he published his Flora Americe Septentrionalis, in which were 
included the plants discovered between 1804 and 1806 by Lewis 
and Clark on their transcontinental journey. Pursh afterwards 
settled in Canada with the intention of continuing his studies of the 
North American flora, but died in Montreal before publishing any 
other work of importance. 
