424 CONTRIBUTIONS TO WESTERN BOTANY 
O. basilaris Eng, Thisia cailed the beaver-tailed cactus, 
and has the most beautiful purple flowers in the genus. It is 
‘Tropical and grows in the hot sands and is the only species with 
obovate-emarginate joints, 4-6 inches long, destitute of spires, 
bluish and with yellow areoles set in dimples on the surface, and 
rather close set, being about 7-8 mm. apart. The fruit is red, 
and dry and filled with the horizontilly lying seeds, which are & 
m. wide by 3.5 mm. thick, and with a thick corky and rounded 
rim 3 mm. thick 
). basilaris var, Treleasei (Coulter). This variety is like the 
type in spreading decumbent over the ground, but has raised ur-- 
oles und 1-3 short spines in them, Bakersfield. 
Q.ursina Weber. This has areoles half an inch apart and 
usually with long and hairlike spines. When the spines are half 
an inch long it becomes O. erinacea Eng. The fruit is very spiny. 
QO. rhodantha Schuman is the only dry-fruited one left. It 
grows high up in the Middle Temperate or Pinus ponderosa area 
of the White mts. The areoles are 2-3 inches apart and is red flow- 
ered. It forms clumps, being decumbent, and has small seeds. 
There is much doubt about the validity of this and rest of the 
species, 
There are two cult species having erect and tree-like trunks, 
that grow with us, O. megacantha Salm Dyck which has truncate 
fruit and large and mostly spineless joints; and O, Ficus-Indica 
a narrow-stemmed cactus with deeply umbilicate fruit are culti- 
vated largely as spineless cacti, having been exploited as such by 
Burbank. 
Species since there are no sure distinctions obtainable. The seed 
character has 3 sharp angles on the outer rim of the circular seed 
joints, or sections of stems, normally vary from round to elliptical 
or oblanceolate and ron from half to @ quarter inch thick, the 
spines are one to few and declined in the axils, variously angled, 
and red, black or brown below. The thin form of this species, O. 
Covillei Br. & R, also bas yellow flowers and is common on the 
foothills, passing readily into the thick-stemmed var. littoralis 
(Eng) Parish, most common along the coast. The speci es has 
uscending to prostrate branches, often a foot long from very spiny 
stems which are erect. he seeds are flattened, 2 mm_ thick by 
2.5 mm wide, with arim .5 mm wide. ©. Mohavensis Eng. isa 
nearly prostrate plant of the juniper belt,with large joints, and 
goes from San Felipe valley to 600) fr, alt. in the higher mts. 
. Vaseyi Br. & R, is another form of occidentalis with thin parts 
and small, reddish joints prostrate, and often purple flowers, 
is common in the foothills. 
