STANDLEY TREES AND SHRUBS OF MEXICO. 917 



what oblique; outer perianth segments linear, spreading or recurved, scat- 

 tered; inner perianth segments broad, more compact than the outer ones; 

 stamens exserted, in a single, somewhat 1-sided cluster; filaments all along 

 the throat ; tube proper about the length of the narrow throat ; fruit globose, 

 small, reddish, setose; seeds few, reddish brown, obovate. 

 The species here listed are the only ones known. 



Flowers strongly bent just above the ovary. 



Branches very slender; ribs 7 or 8 1. A. leptophis. 



Branches stouter; ribs 10 to 12, 



Outer perianth segments narrow, the inner ones apiculate. 



2. A. flagelliformis. 

 Outer perianth segments oblong, the inner ones acuminate. 



3. A. flagTiformis. 

 Flowers nearly straight. 



Inner perianth segments acute 4. A. conzattii. 



Inner perianth segments acuminate 5. A. martianus. 



1. Aporocactus leptophis (DC.) Britt. & Rose, Contr. U. S. Nat. Herb. 12: 



435. 1909. 



Cereus leptophis DC. Mem. Mus. Hist. Nat. 17: 117. 1828. 



Native of Mexico. 



Often creeping; branches cylindric, 8 to 10 mm. thick, rather strongly 7 

 or 8-ribbed ; ribs obtuse, somewhat repand ; areoles velvety, with 12 or 13 

 rigid setaceous spines; perianth segments narrowly oblong, 2 to 3 cm. long, 

 about 6 mm. wide. 



2. Aporocactus flagelliformis (L.) Lem. lUustr. Hort. Lem. 7: Misc. 68. 1860. 

 Cactus flagelliformis L. Sp. PI. 467. 1753. 



Cereus flagelliformis Mill. Gard. Diet. ed. 8. Cereus no. 12. 1768. 



Common in cultivation in Mexico, and elsewhere in tropical regions; native 

 habitat not known. 



Stems at first ascending or erect, but weak and slender or pendent, 1 to 2 

 <;m. in diameter ; branches often prostrate and creeping or even pendent ; ribs 

 10 to 12, low and inconspicuous, a little tuberculate ; areoles 6 to 8 mm. apart ; 

 radial spines 8 to 12, acicular, reddish brown ; central spines 3 or 4, brownish 

 with yellow tips ; flowers 7 to 8 cm. long, opening for 3 or 4 days, crimson ; 

 outer perianth segments narrow, more or less reflexed ; inner perianth seg- 

 ments broader, only slightly spreading; fruit globose, 10 to 12 mm. in diameter, 

 red, bristly ; pulp yellowish. " Flor del cuerno," " floricuerno," " flor del 

 latigo," hierba de la alferecia," " junco," " junquillo," "cuerno." 



This plant is much cultivated in Mexico, and also in the United States, where 

 it is known as rat-tail cactus. An infusion of the dried flowers is employed 

 in Mexico for heart affections. The juice of the plant is said to be acrid and 

 caustic. It is administered internally as a vermifuge, but its use is said to be 

 dangerous. 



3. Aporocactus flagrifonnis (Zucc.) Lem.; Britt. & Rose, Contr. U. S. Nat. 



Herb. 12: 435. 1909. 



Cereus flagriformis Zucc. ; Pfeiff. Enum. Cact. 111. 1837. 



Native of Mexico, the type from San Jos6 del Oro, Oaxaca. 



At first erect and rather stout, afterwards creeping, very much branched; 

 branches green, 10 to 24 mm. in diameter ; ribs 11, very low, obtuse, somewhat 

 tuberculate; areoles small, 4 to 6 mm. apart; radial spines 6 to 8, 4 mm. long, 

 acicular, horn-colored; central spines 4 or 5, shorter than the radials but 



79688—24 6 



