818 OPUNTIACEAE 



8. Opuntia Dill^nii (Ker.) Haw. Stems erect, 9-12 dm. tall, proliferous, the 

 joints oval or elliptic, 10-20 cm. long: cushions of bristles remote above, a cluster of 

 4-6 short rigid or subulate yellow spines, varying from very short to 3.5 cm. in length: 

 flowers yellow or reddish yellow, 7.5-10 cm. broad: fruits rather pear-shaped, 5-6 cm, 

 long, edible. [O. Tuna, Chapm. Not Mill.] 



In sandy soil, peninsular Florida and the Keys. Also in the West Indies and Central 

 America. 



9. Opuntia Lindheimeri Engelm. Stems erect, 12-18' dm. tall, forming a 

 woody trunk, sometimes 15 cm. thick and clothed with a grayish bark, the joints pale 

 green, obovate or orbieular-obovate, becoming 30 cm. long and sometimes 22 cm. 

 broad; cushions of bristles remote: spines few, 2.5-3.5 cm. long, or some shorter, 

 flattened or angled, yellow or yellowish, straight or curved, deflexed or spreading: 

 flowers yellow within, red without, 6-7.5 cm. broad: fruits globose-obovoid or nearly 

 so, 5 cm. long, purplish without, the pulp insipid or nauseous: seeds 3-4 mm. long, 

 margined. 



In valleys, Texas and Mexico. 



10. Opuntia leptoc^rpa Mackensen. Stems mostly ascending, 5 dm. tall or 

 less, the joints thinnish, obovate to oval or elliptic 9-20 cm. long or longer: cushions 

 of bristles remote: spines few, or sometimes wanting, mostly 1-3 cm. long, terete or 

 slightly flattened, spreading, or the lower one sometimes deflexed: flowers yellow, 

 except the pale-reddish brown or brown center, about 7 cm. broad: fruits club-shaped, 

 5-9 cm. long or longer, purplish or crimson, the pulp nauseous: seeds about 4 mm. 

 long, margined. 



In dry soil, near San Antonio, Texas 



11. Opuntia tortispina Engelm. Stems procumbent, the branches ascending, the 

 joints orbieular-obovate, 15-20 cm. long, with cushions of yellowish bristles, 2.5-3.5 

 cm. distant: spines white, 3-5 together, 3.5-6 cm. long, angled, channeled, often 

 spirally twisted, accompanied by 2-4 spines about i as long, below them: flowers 

 sulphur-yellow, 6—7.5 cm. long: seeds suborbicular, 4-6 mm. broad. 



On plains, Nebraska to Oklahoma and Texas. 



12. Opuntia fiisco-^tra Engelm. Stems procumbent, the branches ascending, the 

 joints obovate, 6-7.5 cm. long, tuberculate: bristle-cushions remote, tomentose, the 

 upper one unarmed, the bristles reddish brown : spines brownish black, usually solitary, 

 2.5-3 cm. long, short, rather erect, an additional short deflexed one sometimes present : 

 flowers yellow, 7.5 cm. broad: fruits unknown. 



In sterile soil or on prairies, Texas. 



13. Opuntia in6r2nis DC. Stems erect, 12-18 dm. tall, proliferous: trunk 

 cylindric, woody in age, the joints thick, obovate to elliptic, 10-15 cm. long, with the 

 cushions of bristles immersed, spineless or sometimes with a very short spine : flowers 

 yellow, 7.5-10 cm. broad: fruits obovoid, bristly, 5-6 cm. long, edible, the pulp red. 

 [0. Ficus-Indica Chapm. Not Mill.] 



In sand, peninsular Florida and the Keys. Also in the West Indies. 



14. Opuntia P6s-Corvi LeConte. Stems prostrate or diffusely spreading, 3-7 

 dm. long, the joints narrowly ovoid to obovoid, nearly terete, 2.5-7.5 cm. long, light 

 green, loosely attached to each other: bristle-cushions quite numerous, the upper ones 

 armed, the bristles pale: spines slender, solitary or 2-3 together, straight, 2.5-3.5 

 cm. long, often flattened at the base and twisted: flowers yellow, 3.5-4 cm. broad: 

 fruits obovoid, 12-15 mm. long, rose-purple, bristly: seeds often 4-5 mm. long, with 

 an obtuse margin. 



On sandy coasts or adjacent ridges, Georgia and Florida. 



15. Opuntia Tr^cyi Britton. Stems depressed, diffusely much-branched, the 

 joints oblong to linear-oblong, thick, but somewhat flattened, 6-8 cm. long, pale green: 

 bristle-cushions rather numerous, the bristles brownish : spines solitary or 2-4 together, 

 slender, 3.5 cm. long or less, light gray with darker tips: flowers yellow, about 4 cm. 

 broad: petals obovate, 2-2.5 cm. long, apiculate. 



In sandy soil near the coast, Biloxi, Mississippi. 



16. Opuntia polyacdntha Haw. Stems prostrate, branching into large masses, 

 the joints suborbicular, 5-10 cm. or rarely 15 em. long, light-green, tuberculate, 

 bearing leaves 3-4 mm. long: bristle-cushions rather numerous, all armed, the bristles 

 •eddish brown: spines 8^15 together, the 5-10 outer radiant, very slender, whitish, 



