352 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM, 
in circumference, as measured by a tape line drawn as closely to the trunk as the 
projecting spines would permit. The usual height, however, is 1 to 2 meters. 
This Echinocactus was originally discovered by Leon Diguet on Santa Catalina 
Island, in the Gulf of California, about 100 miles north of La Paz. It was re-collected 
by Rose at the type locality and on Carmen Island in April, 1911. The species is 
not known to occur on the mainland. 
Echinocereus brandegei (Coult.) Schum. PLATE 124. 
Discovered at Campo Alemdn by Brandegee, April 24, 1889. It was first: noticed 
by us and collected at about 300 meters altitude in the bottom of the canyon at San 
Pablo. From this point southward to Matancita it was seen in a number of places 
along our route. Unlike the species of Echinocactus, it prefers the softer soil in the 
bottoms of canyons along the backbone of the Peninsula or on the plains near the 
west coast. It was noted as far west as the Santa Clara Mountains, but was more 
abundant on the coastal plain between San Jorge and Matancita, where it was col- 
lected in flower November 14. It grows in thick bunches usually not more than 0.5 
to 1.5 meters in diameter, the stems 15 cm. in length, some upright and others reclining. 
Lemaireocereus thurberi (Engelm.) Britt. & Rose. 
PITAHAYA DULCE. ORGAN FIPE CACTUS. PLATE 125, A. 
The “pitahaya dulce,’’ so called in Lower California, was originally described from 
“a rocky canyon near the mountain pass of Bacuachi, a small town on the road to 
Arispe, in Sonora.’’ It was first seen on our route near Pozo Altamirano and afterwards 
from this point southward to Cape San Lucas we found it fairly common, except on 
very sandy areas. Its range in the Peninsula thus includes the southern half, from 
near latitude 28°. It occurs also on Cerralvo Island. The species grows among the 
rocks on the lava-covered mesas along the backbone of the Peninsula and on the plains 
near the Pacific coast. The fruit is gathered in quantities by the people, but seemed 
to us less palatable than that of the next. 
Lemaireocereus gummosus (Engelm.) Britt. & Rose. 
PITAHAYA AGRIA. PLATE 126, A. 
Well known throughout its range by the name given. It was first noted and col- 
lected by us in the vicinity of Yubay and was one of the most abundant and generally 
distributed cactuses along our route from this point southward to Cape San Lucas. 
It is also common on Magdalena, Margarita, Espfritu Santo, and Cerralvo islands. 
Brandegee recorded the species from San Martfn and Cedrosislands, and more recently 
Dr. Rose has collected it on the islands of Catalina and Santa Cruz in the Gulf of 
California. The plants grow 1.5 to 2 meters high, with numerous branches, The 
large fruit is slightly tart and very agreeable to the taste. It is much prized by the 
natives and to us seemed much superior to that of L. thurberi, which is sweeter and 
more insipid. 
Lemaireocereus eruca (T. S. Brandeg.) Britt. & Rose. CHrrinoLaA. PLatr 127. 
We first saw this remarkable cactus on the coastal plain near Santo Domingo, about 
30 miles north of Matancita and here made a collection. From this point southward 
it was noted at intervals on the plains as far as the Llano de Yrais and on the lower 
and more sandy parts of Magdalena Island. The stems grow 1 to 3 meters in length 
and are nearly prostrate, and from this habit and their long whitish recurved spines 
have aptly been likened to huge caterpillars. The growing ends of the branches 
stand up from the ground, but progressive growth leaves the main body lying pros- 
trate. The stems become rooted along the lower sides and gradually die behind, 
resulting in a slow progression of the living portion along the ground. Multiplication 
of individuals frequently results from the decay of connecting parts. In some places 
