FEROCACTUS. 



137 



18. Ferocactus alamosanus Britton and Rose. 



Echinocactus alamosanus Britton and Rose, Contr. U. S. Nat. Herb. 16: 239. 1913. 



Plants usually single, sometimes in clusters, somewhat flattened above, green, 30 cm. in diameter 

 or more; ribs about 20, narrow; spines all yellow; radials usually 8, 3 to 4 cm. long, more or less 

 spreading; central single, porrect or erect, somewhat flattened laterally, 6 cm. long and a little 

 longer than the radials; flower-buds covered with ovate, ciliate scales, these brownish except in the 

 margin; fruit unknown. 



Type locality: Alamos Mountain, Mexico. 



Distribution: Southern Sonora, Mexico. 



This species is quite unlike anything we have yet seen from the west coast of Mexico. 

 A small living plant of the type collection was brought to Washington by Dr. Rose in 1910, 

 but is still quite small, being only 10 cm. in diameter. It has now been sent to Mr. 

 Wm. Hertrich, superintendent of the Huntington Estate near Los Angeles, where it will 

 be planted in the open and given a chance to 

 develop. The illustration cited below was made 

 from this plant. 



Mr. Ivan M. Johnston has collected this species 

 or a closely related one on the hill- sides about San 

 Carlos Bay, Sonora (No. 4348). He says that it is 

 6 dm. high, 5 dm. in diameter and has 23 ribs. He 

 describes the flower as clear lemon-yellow with the 

 outer segments greenish red at tip; the scales on 

 the ovary are broadly ovate, apicular, ciliate. 



Illustration: Contr. U. S. Nat. Herb. 16: pi. 66, 

 as Echinocactus alamosanus. 



Figure 145 is from a photograph of the living 



plant Collected by Dr. Rose. F 1G. M5 -Ferocactus alamosanus. 



19. Ferocactus glaucescens (De Candolle). 



Echinocactus glaucescens De Candolle, Mem. Mus. Hist. Nat. Paris 17: 115. 1828. 

 Echinocactus pfeifferi Zuecarini in PfeifTer, Enum. Cact. 58. 1837. 

 Echinofossulocactus pfeifferi Lawrence in Loudon, Gard. Mag. 17: 318. 1841. 



Globular, 2 to 4 dm. in diameter, or a little higher than broad, glaucous; ribs 11 to 15, somewhat 

 flattened, acute, 2 to 3 cm. high; areoles 8 to 12 mm. apart, oblong, 12 to 20 cm. long, yellowish, 

 tomentose when young; radial spines 6, nearly equal, rigid, only slightly spreading, straight, 2.5 to 

 3 cm. long, pale yellow at first, when old blackish, more or less banded; central spine solitary, similar 

 to the radials; flowers yellow, 2 cm. long, perhaps broader when fully expanded; outer perianth-seg- 

 ments ovate, acuminate, sometimes brownish on the back, ciliate on the margins; inner perianth- 

 segments oblong, usually only acute, somewhat toothed or lacerate; stigma-lobes slender, cream- 

 colored; scales on the ovary brownish, ovate, acute, ciliate on the margins, imbricate. 



Type locality: Toliman, Mexico. 



Distribution: Eastern central Mexico. 



Our knowledge of this species is drawn not only from illustrations and published de- 

 scriptions but also from a plant obtained by Dr. Rose from Hidalgo, Mexico, in 1915, 

 which has since been grown in the cactus house of the U. S. Department of Agriculture, 

 but has never flowered. Dr. Rose, however, found it in flower at La Mortola, Italy, in 

 191 2, and a few flowers were obtained. 



Schumann thought that Echinocactus dietrichianus Forster (Hamb. Gartenz. 17: 160. 

 1 861) was probably referable to E. pfeifferi. 



Schumann refers here E. theionacanthus Lemaire (Cact. Aliq. Nov. 22. 1838) and E. 

 theiacanthus Lemaire (Cact. Gen. Nov. Sp. 86. 1839) but he has the names interchanged. 

 The latter seems to have been based on E. mammilijer Miquel (Linnaea 12: 8. 1838), 



