854 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
from the U. 8. National Herbarium, no. 3,' catalogued by Rose, for whom it is appro- 
priately named. The stems pendent from rocks at Comandt are sometimes 6 feet 
long.” 
Myrtillocactus cochal (Orcutt) Britt. & Rose. 
Originally described from Todos Santos Bay; first seen by us in the hills along the 
road from Pozo Altamirano to San Pablo, October 3. It was at this time in flower, 
and the resemblance to M. geometrizans, the garambullo,? with which we became 
familiar in the plateau region of Mexico, was noted at once. The flowers are small, 
whitish, and inconspicuous. This was one of the rarer cactuses along our route from 
this point southward to the Cape. It was afterwards seen near Tinaja de Santana, 
in the hills about 20 miles east of San Ignacio, along the road from Agua Grande to 
Paso Hondo, a few miles north of Comandti, and near San José del Cabo. Brandegee 
records the species from San Martin Island. 
Opuntia pycnantha Engelm. 
Four species of flat-jointed Opuntia are known to occur in Lower California. The 
type of O. pyenantha came from Magdalena Bay, but little is yet known of the distri- 
bution of the species. It was collected by Brandegee on Magdalena Island in March, 
1889, and by Rose at Santa Maria Bay in March, 1911. Short, closely set, yellowish 
spines distinguish this form from its insular representative, the subspecies margaritana. 
Opuntia pycnantha margaritana Coulter. 
Margarita Island is the type locality of this form, which was described by Coulter 
in 1896, It was again collected there by Rose in March, 1911. It differs from 0. 
pycnantha of the mainland in its reddish instead of yellowish spines. 
Opuntia tapona Engelm. TUNA TAPONA, 
A species bearing edible fruit, described from material collected by William M. 
Gabb near Loreto while on his overland journey in 1867. Specimens recently col- 
lected by Rose indicate that its range extends thence to San José del Cabo. Rose 
also obtained this species on Pichilinque Island and on Espfritu Santo Island, where 
we had also collected it in 1906. 
Opuntia comonduensis (Coulter) Britt. & Rose. 
The known range of this species extends on the mainland from Comandt, the type 
locality, southward to San José del Cabo, where the plant was collected by Rose in 
March, 1911. He also obtained specimens on Carmen Island in April, 1911. 
Opuntia sp. PLATE 129, B. 
A species with short pinkish thorns grows abundantly along with O. cholla or a 
form of this in the vicinity of Agua Dulce and as far southward as Comandt. 
Opuntia cholla Engelm. CHOLLA. PLATE 128, A. 
One or more species of the O. cholla type are among the most abundant and gener- 
ally distributed cactuses throughout the desert region from Cape San Lucas north to 
the basal slopes of the San Pedro Martir mountains. This type of cactus does not occur 
or is not abundant on the desert near the delta of the Colorado nor in the northwest 
coastal region. 
Opuntia bigelovii Engelm. PLATE 128, B. 
This species, distinguishable at once from O. cholla by joints much more thickly 
beset with whitish spines, was seen in a few places near the Gulf coast from the Coco- 
pah mountains south to Calamahué. It is abundant on the coastal plain near San 
Felipe Bay. 
11: 70, 1890. 2 See under Lophocereus schottii, p. 353. 
P P 
