THE CACTACEAE. 



136 



ovary 3 to 3.5 cm. long, with very many areoles bearing numerous glochids; style thick; stigma- 

 lobes 8 to io, greenish white; fruit reddish, clavate, 4.5 cm. long, with a depressed umbilicus; seeds 

 small, 3 to 3.5 mm. broad. 



Type locality: Argentina, between Rio Negro and Rio Colorado. 



Distribution: Southern Argentina. 



According to Dr. Spegazzini, this species is not near to any of the known South Ameri- 

 can species, but resembles somewhat the North American species 0. microdasys and 0. 

 basilaris. We know it only from the description. 

 OPUNTIA CALANTHA Griffiths, Bull. Torr. Club 43: 524. 1916. 



A low, creeping, prostrate plant 15 cm. high, one meter in diameter; joints obovate, narrowed 

 above and below, inequilateral, n cm. long, 4 cm. broad, tuberculate-wrinkled, mostly deep green; 

 areoles i to 1.5 mm. long, obovate, at first tawny, turning gray; leaves small, subulate, cuspidate, 

 red. i mm. long; glochids yellow; spines 5 to io, up to 5 mm. long; flowers carmine; fruit globular, 

 1.5 cm. in diameter. 



Recorded as probably of South American origin and usually distributed as Opuntia 

 microdisca, but from which it is said to differ very much. The plant is known to us only 

 from the description of cultivated specimens. 



Series 9. STRIGILES. 



The series consists of a single species, native of 

 Texas. It is a low, bushy plant with large joints bear- 

 ing many areoles, these close together, each with sev- 

 eral acicular, reddish brown spines; the fruit is small. 



131. Opuntia strigil Engelmann, Proc. Amer. Acad. 3: 

 290. 1856. 



Suberect, 6dm. high; joints orbicular to obovate, io to 12.5 cm. 

 long; areoles close together, prominent ; spines 5 to 8, spreading, many 

 of them appressed to the joint and deflexed, red to reddish brown with 

 lighter tips, the longer ones 2.5 cm. long; glochids numerous; flowers 

 unknown; fruits small, nearly globular, 12 mm. in diameter, trun- 

 cate, red; areoles on fruit very small; seeds 3 mm. broad. 



Type locality: In crevices of limestone rock, between the 

 Pecos River and El Paso, Texas. 



Distribution: Texas. 



A rare plant, first collected by Charles Wright in 1851. 

 Engelmann says in the Mexican Boundary Report that it 

 was also collected by Wright and Bigelow, but there is no 



mention of it in his report on Bigelow's plants, nor do we find specimens in the Engelmann 

 herbarium, so that it would appear that this reference to Bigelow was a mistake. Bigelow, 

 it is true, crossed the River Pecos, on which the type was found, but it was well up in New 

 Mexico and not in Texas, where it was crossed by Charles Wright. It was more recently 

 collected by Nealley somewhere in Texas. The place of collection by Wright and the later 

 one by Nealley are very indefinitely indicated on the labels accompanying the specimens. 



Illustration: Cact. Mex. Bound, pi. 67. 



Figure 171 is copied from the illustration above cited. 



Series 10. SETISPINAE. 



Bushy or depressed species, with tuberous or thickened roots, broad, flat, thin joints, and elon- 

 gated, acicular, brown spines which fade whitish; their fruits are large and juicy. We recognize 

 six species, natives of the south central and southwestern United States and northern Mexico. 

 They approach the Tortispinae on the one hand and the Phaeacanthae on the other. 



FIG. 171. Opuntia strigil. 

 Xo.4. 



