OPUNTIA. 



133 



Fig. 168. — Opiintia 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: Kastern Texas. 



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



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



Atee at Rockport, Texas, in 1911. 



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

 Opuntia rubifi^ora 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 ruhiflora was used by Davidson a few months eariicr 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. ^2%. 0. sulphurea 



Spines stout, subulate ,29. 0. soehensii 



Ispines slender, acicular ,,0. 0. microdisca 



i'lowers red. . 



