OPUNTIA. 



133 



Fig. 168. — Opuntia delicata. 



127. opuntia fuscoatra Engelmann, Proc. Amer. Acad. 3: 297. 1856. 



Diffuse prostrate plants; joints orbicular to obovate, somewhat tuberculate, 5 to 8 cm. long, 

 areoles 12 to 20 mm. apart, very large for the group; spines single or in twos or threes, one rather 

 stout, sometimes a little flattened, 2.5 to 3 cm. long, yellow to dark brown or even nearly black; 

 usually from the lower areoles; glochids numerous, brown; flowers 7.5 cm. broad, yellow; petals very 

 broad; stigma-lobes 5; ovary 2.5 cm. long, slender; fruit 4 to 5 cm. long, red; seeds 4 mm. broad. 



Type locality: Sterile places of prairies west of Houston, Texas. 

 Distribution: Eastern Texas. 

 Illustrations: Pac. R. Rep. 4: pi. 11, f. 4. 



Plate XXIII, figure i, represents a flowering joint of the plant collected by W. L. Mc- 

 Afee at Rockport, Texas, in 1911. 



127 a. Opuntia macateei sp. nov. (See Appendix, p. 221.) 

 Opuntia rubiflora Griffiths, Bull. Torr. Club 43: 529. 1916. 



Described as a spreading plant 3 to 4.5 dm. high and a meter broad, with obovate, 

 green joints 12 to 18 cm. long, few white spines up to 5 cm. long with brown or straw- 

 colored bases, and pink flowers. The species is based on cuttings received from European 

 collections, and its origin is unknown. 



We have received a similar if not identical plant from Haage and Schmidt of Erfurt, 

 Germany, and we suspect it to be a hybrid, having one of the Tortispinae as one of its 

 parents. 



The specific name rubiflora was used by Davidson a few months earlier than by 

 Griffiths for another plant. 



Series 8. SULPHUREAE. 



Low or prostrate species, with rather thick, flat, tuberculate joints; fruit small, nearly globular. 

 Three species, natives of central and southern South America. 



Key to Species. 



Flowers yellow. 



Spines stout, subulate 128. 0. sulphurea 



Spines slender, acicular 129. O, soehrensii 



Flowers red ' 130. 0. microdisca 



