New species of Opuntia 
DaAvip GRIFFITHS 
(WITH PLATES 2 AND 3) 
A living assemblage of 2,400 collection-numbers of Opuntia 
has been established at Chico, California. The majority of the 
plants have reached fruiting condition. The plantation represents 
in the largest measure my own field work supplemented by dona- 
tions, purchases from other co!lectors,and introductions through the 
Office of Seed and Plant Introduction of the United States Depart- 
ment of Agriculture. All of the species described below have been 
propagated vegetatively in this collection, have been studied in 
their native habitat in all but one instance, and the majority of 
them have been grown to maturity from seed, either from the 
type or from previous collections. 
» Opuntia humistrata sp. nov. 
A densely pruinose, prostrate to ascending species, with long 
radiating, branched, reclining, tangled arms, 30 cm. igh, and 
forming bunches a meter in diameter; joints obovate to elliptical, 
broadly to sharply rounded above, and stipitate based, or widest 
at middle, and long, attenuated above and below, commonly ~ 
6 X 15 cm., but may be 5 X 18 cm., and again commonly 5 X 10 
cm., surface flat, only very slightly raised at areoles even when 
young, at first dull medium to yellowish green, strongly turgid, 
with slight tinge of red about areoles of the edges especially, in the 
main densely pruinose; leaves reddish tinged, circular in section, 
subulate, cuspidate, 5 mm. long, mostly ascending, and finally 
curving inwardly; areoles at first tawny with light brown wool, 
which is soon obliterated by the spicules, subcircular to broadly 
obovate, 2 mm. in diameter, soon becoming 3 to 4 mm. in diameter; 
mm. long, and completely fi 
tuft 3 mm. long; spines none; flowe 
Opuntia basilaris Engelm. & Bigel., 
globose or more elongate, greenish or white with a blush of red, dry. 
This species belongs to the Opuntia basilaris group, and it is dis- 
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