STANDLEY TBEES AND SHEUBS OF MEXICO. 945 



12. Ferocactus covillei Britt. & Rose, Cactaceae 3: 132. 1922. 

 Sonora, the type from Altar. Southern Arizona. 



Plant simple, globular to short-cylindric, often 1.5 meters high ; ribs 22 to 

 32, 2 to 4 cm. high, rather thin, when young more or less tubercled, but when 

 old hardly undulate ; areoles on small plants distant, often 3 to 4 cm. apart, 

 on old and flowering plants approximate or contiguous, densely brown-felted 

 when young, naked in age, the spine-bearing areoles large and circular, the 

 flowering areoles more elongate and complex, divided into three parts, the 

 lower part bearing spines, the central part spinesceut bands, and the upper 

 part the flower ; spines sometimes red to white ; radial spines 5 to 8, some- 

 what spreading, subulate, straight or more or less curved backward, 3 to 6 cm. 

 long, annulate ; central spine always solitary, very variable, straight or with 

 the tip bent or even strongly hooked, annulate, terete to strongly flattened 

 or 3-angled, 3 to 8 cm. long ; upper areoles of old plants bearing 5 to 7 glands, 

 becoming spinescent, 5 to 6 mm. long ; flowers described as red, tipped with 

 yellow, sometimes reported as yellow throughout, 6 to 7 cm. long ; inner perianth 

 segments linear-oblong, acuminate, often serrate; fruit oblong, 5 cm. long, 

 bearing a few broad scales; seeds black, dull or shining, nearly smooth or 

 slightly pitted, 2 mm. long. 



13. Ferocactus peninsulae (Weber) Britt. & Rose, Cactaceae 3: 133. 1922. 

 Echinocactus peninsulae Weber, Bull. Mus. Hist. Nat. 1: 320. 1S95. 

 Southern Baja California. 



Simple, erect, 2.5 meters high, clavate to cylindric; ribs 12 to 20, prominent; 

 areoles 4 cm. apart or even less in old plants; spines red with yellow tips; 

 radial spines 11, spreading, straight, terete, more or less annulate, the lower 

 ones stouter and more colored ; central spines 4. 



14. Ferocactus rectispinus (Engelm.) Britt. & Rose, Cactaceae 3: 134. 1922. 

 Echinocactus emoryi rectispinus Engelm. ; Coulter, Contr. U. S. Nat. Herb. 



3: 3G2. 1896. 



Echinocactus rectispinus Britt. & Rose, Journ. N. Y. Bot. Gard. 12: 269. 1911. 



Central Baja California ; type from Mulege. 



Globose to cylindric, 1 to 2 meters high ; radial spines 8 to 12, the three up- 

 per spines stouter and sometimes curved; central spine one, 9 to 13 cm. long, 

 rather slender, nearly straight, never hooked; flowers 6 cm. long, yellowish; 

 scales on ovary rounded, thin-margined, sometimes ciliate, naked in the axils; 

 inner perianth segments lemon-yellow, lanceolate, 5 cm. long, acuminate. 



15. Ferocactus orcuttii (Engelm.) Britt. & Rose, Cactaceae 3: 134. 1922. 

 Echinocactus orcuttii Engelm. West. Amer. Sci. 2: 46. 1886. 



Type from Palm Valley, Baja California. 



Single, or cespitose in clusters of 15 to 20 stems, 60 to 130 cm. high, 25 to 45 

 cm. in diameter ; ribs 13 to 30, somewhat spiraled, obtuse, somewhat tubercu- 

 late; areoles approximate; spines reddish, straight or simply curved, all annu- 

 late, angled or flat ; radial spines 9 to 13, spreading ; central spines 4, stouter 

 than the radials ; flower 3 to 5 cm. long, dull crimson ; perianth segments 

 short-oblong, rounded at apex with a more or less erose margin ; scales on the 

 ovary orbicular, small ; fruit described as pulpy, crimson, scaly ; seeds numer- 

 ous, small. 



16. Ferocactus robustus (Link & Otto) Britt. & Rose, Cactaceae 3: 135. 1922. 

 Echinocactus robustus Link & Otto, Allg. Garteuz. 1: 364. 1833. 



Puebla, the type from Tehuacfln. 



In large clumps, often 3 meters, rarely 5 meters in diameter, 1 to 1.3 meters 

 high, with hundreds of branches ; ribs 8, prominent in young growth, but be- 



