28 THE CACTACEAE. 
while in Mexico it is called cabeza del viego. It has often been regarded as a variety of 
E. reichenbachii, but it is abundantly distinct. It is known in the trade under various 
names, among which are Cereus candicans and Echinocereus candicans, a name which 
belongs properly to a very different plant from Argentina, Cereus rigidissimus, C. robustior, 
and Echinocereus robustior, but none of which has been formally published. Here also 
belong the names Echinocereus rigidispinus, E. pectinatus robustior (Monatsschr. Kakteenk. 
7:95. 1897), and perhaps FE. pectinatus candicans (Monatsschr. Kakeenk. 3: 111. 1893). 
Fics. 28 and 29.—Echinocereus rigidissimus. 
Benson sree specimen which we have seen was collected by Dr. J. W. Gidley near 
spines Were. nearly all red “senaus re was fully 2 dm. tall and 1 dm. in diameter. The 
red, separat : oe 
brilliant and striking appestance. y very narrow bands of white ones giving the plant a 
Handby eo oe Amer. Hort. Bailey 2: 519. f. 748; De Laet, Cat. Gén. f. 36; Schelle, 
pl. 1331, as E " 133. - 63, as Echinocereus pectinatus rigidissimus: Gartenflora 39: 
- 1331, +. pectinatus robustus; Cact. Journ. 1: pl. for September; 2: 18: (?) Balt. Cact. 
Journ. 2: 88; West Amer Sci. 7: hy . 
2: f. 1376, » Cl. 73 236, as Echinocereus candicans; Stand. Cycl. Hort. Bailey 
Figure 28 is from a photograph of a plant sent from 
