Missouri Botanical 
Garden Bulletin 
Vol. III St. Louis, Mo., April, 1915 No. 4 
THE YARETA OR VEGETABLE SHEEP OF PERU 
Professor Irving W. Bailey, who for several years resided 
at Arequipa, Peru, recently sent to the Garden for identifica- 
tion a dried specimen of a very curious plant which is known 
by the native Peruvians as “Yareta” or “vegetable i 
The plant grows abundantly among rocks at high altitudes 
along the Andes of Bolivia and Peru, where it constitutes a 
conspicuous feature in the landscape because of its peculiar 
manner of growth in developing the so-called “‘polster” or 
cushion formation. 
Similar compact masses of plant growth are frequently 
found on high mountains, as well as in arctic and antarctic 
regions. Such, for example, are the relatively small clumps 
or cushions of Diapensia lapponica L. on the alpine summits 
of New England and in northern Europe, also several of the 
se in the Rocky Mountains, and the well-known 
“vegetable sheep” (Raoulia mammillaris Hook.) of New 
Zealand; but nowhere in the world are known to occur such 
huge masses as are developed by the Yareta (Azorella sp.) 
of the Andes and by other members of this genus in the 
Falkland Islands. 
The size and general appearance of this peculiar plant are 
shown in Plate 1, made from a photograph taken by Professor 
Bailey on Mt. Chachani, near Arequipa, at an elevation of 
fully 17,000 feet above sea-level. It forms hillocks or small 
mounds often becoming three feet high and sometimes sev- 
eral feet in diameter. spaniel the entire mound is made 
up of a single plant, not of a colony of individuals, and it 
attains this enormous size and extreme compactness by a 
rocess of repeated branching (Plate 2), so that the ultimate 
pe are closely crowded and the outer surface is con- 
tinuous (Plate 2). The flowers of the Yareta are very tiny, 
only about two millimeters, or less than one-eighth of an 
inch, long, and are borne in small sessile, axillary, involu- 
crate clusters near the tips of the branches; and the fruit is 
somewhat like a miniature caraway seed. ae 
