n8 



THE CACTACEAE. 



KIG. 146. Opuntia depressa, in the foreground. 



Series 5. BASILARES. 



We recognize eight species as forming this series. They are low or bushy, much branched 

 plants, with flat, thin, broad joints, the areoles small, usually numerous and close together. 



KEY TO SPECIES. 



Joints papillose, not pubescent. 



Fruit juicy, red 107. 0. lubric'a 



Fruit dry or nearly dry 108. O. treleasei 



Joints mostly manifestly pubescent. 

 Spines none or few. 



Flowers red 109. 0. basilaris 



Flowers yellow to orange. 

 Joints bright green. 



Glochids long no. O. microdasys 



Glochids short 1 1 1 . O. macrocalyx 



Joints grayish green 1 12. 0. rufida 



Spines very numerous. 



Areoles close together 1 13. O. pycnantha 



Areoles distant . 1 14. 0. comonduensis 



107. Opuntia lubrica Griffiths, Rep. Mo. Bot. Card. 21: 169. 1910. 



"A low ascending, spreading species very similar in habit to 0. microdasys, frequently 4^ dm. 

 high and when well developed 10 dm. or more in diameter; joints sub-circular to obovate, about 15 

 by 20 cm., or in case of last joints of previous year about 12 by 15 cm., bright, glossy, leaf-green, very 

 evidently papillate but scarcely pubescent under a lens; leaves subulate, cuspidate-pointed, 6 to 9 

 mm. in length; areoles 15 to 22 mm. apart, 4 to 6 mm. in diameter, sub-circular, prominent; spicules 

 prominent, 4 to 5 mm. in length, erect, bushy, in crescentic tufts in upper portion of areoles, becom- 

 ing much more numerous in age, and at 2 to 4 years completely filling the areole, and, like 0. riifida 

 and some other species, becoming very abundant and conspicuous by proliferation of areolar tissue 

 into short raised or columnar structures; spines exceedingly variable, sometimes nearly absent, again 

 quite abundant and irregularly distributed, none to many, mostly i to 3, becoming more numerous 

 with age and in scattering areoles to as high as 16, mostly about 1 2 mm. long, but sometimes 2^2 cm., 

 yellowish, translucent, bonelike, sometimes darker at base; fruits decidedly acid, light red without 

 with yellowish green rind and red pulp; seed small, thin shelled, about 3 mm. in diameter. " 



Type locality: Near Alonzo, Mexico. 

 Distribution: Known only from the type locality. 



