25 
Corolla of numerous petals: berries clavate, over 4.3 cm. 
omg. x. O. lata. 
Corolla of few petals: berries short-obovoid, less than 3.5 
cm. long. 2. O. Poliardi. 
Plants erect, sometimes copiously branched, thus bushy and 
diffuse: joints pale-green. 3. O. ausirina. 
II. Ammophilae 
Plants tree-like, the stout or stocky trunk divided above into 
few or many divergent branching joints, sometimes sema- 
phore-like: joints gray-green, usually copiously armed. 4. O. ammophila. 
Ill. Ficus-indicae 
Plants robust, more or less tree-like, the thick joints sup- 
Ported on the subterete trunk, mostly about 3 dm. long: cor- 
olla large, mostly 8-10 cm. wide: berries red or orange, said 
to be sometimes yellow. 5. O. Picus-indica. 
IV. Dillenianae 
Areolae bearing 4-13 short spines which seldom exceed the 
bristles, the joints thus apparently unarmed: corolla short- 
OH. O. keyensis. 
long spines which much exceed the 
bristles, the joints thus prominently armed; or indi- 
vidual joints sometimes spineless: corolla rotate. 
Spines decidedly flattened, often curved, in clusters of 
< 
campanulate, 
Areovlae bearing 2-6 
m dense clusters of protruding bristles, the 
fotnte aa rigidly armed: plants copiously floriferous 
and fructiferous. 7, OQ. Dilleniti 
Spines terete or nearly so, straight, solitary or 2 
together, from small clusters of inconspicuous eae 
the joints not rigidly armed: plants sparingly floriferous 
and fructiferous. 8. O. siricta. 
V. Elatiores 
Plants large, stout, erect, but widely branched, bushy, not 
fragile: joints thick, but broad: hypanthium broadly turbi- 
nate: outer sepals very broad: corolla bright-yellow. 9. O. sebrina. 
VI. Curassavicae 
Plants small, prostrate, exceedingly fragile: joints narrow, often 
as thick as wide: hypanthium narrowly turbinate: outer 
epals narrow: corolla lemon-yellow. to. O. Drummonidil. 
VU. Brasilienses 
Plants tree-like, the trunk and branchlets strikingly different: 
young spines pale yellow with brown tips; mature spines 
gray with brown tipe; berries subglobose to oval. tr. O. brusiliensis. 
