359 
Desert region of Chihuahua, “southwest of E] Paso toward Lake 
Guzman, over an area of 60 or 80 miles in extent.” 
The species is clearly very near E. polycephalus, but should be distinguished from 
it readily by its simple habit and white spines. 
4. Echinocactus texensis Hopf. Allg. Gart. Zeit. x, 297 (1842). 
Echinocactus lindheimeri Engelm. Pl. Lindh. 246 (1845). 
Mostly depressed (sometimes globose), 20 to 30 cm. in diameter, 10 to 
15 em. high, simple: ribs mostly 21 (sometimes 27, and in smaller 
specimens 13 or 14) and undulate: spines stout and fasciculate, reddish, 
compressed; the exterior 6 or 7 radiant, straightish or curved, unequal, 
12 to 20 mm. long in some cases, 30 to 50 mm. in others, much shorter 
than the solitary and stout recurved central, which is sometimes 4 to 6 
mm. broad: flowers about 5 em. long, particolored (scarlet and orange 
below to white above): fruit subglobose, scarlet, 16 to 18 mm, in diam- 
eter: seeds reniform and compressed, black, smooth, and shining (or 
minutely pitted), 2.4 to 2.8 mm. long. (Ill, Cact. Mex. Bound. t. 33, 
figs. 1-6)—Type, Lindheimer 44 in Herb. Mo. Bot. Gard. 
Common from the Colorado River of Texas to the Rio Grande, 
extending as far west as the Pecos, and southward into the northeast- 
ern states of Mexico. 
Specimens examined: TEXAS (Lindheimer 44, and of 1850; Wright 
of 1848 and 1849; Bigelow of 1853; Hall 234; Nealley of 1891, near 
Del Rio): TAMAULIPAS (Berlandier 1836): Nurvo LEon ( Wislizenus 
ot 1847): CoAHUILA (Gregg of 1847): Mexico in general (Poselger of 
1850): also specimens cultivated in St. Louis in 1864, 
According to Labouret, this is 2. courantii Lemaire, but I have had no means of 
verifying the statement. 
+ + Ribs 5 to 10, very broad and obtuse. 
5. Echinocactus horizonthalonius Lem. Cact. Gen. Nov. 19 (1839). 
Echinocactus equitans Scheidw. Bull. Acad, Brux. vi, 88 (1839), 
Echinocactus horizonthalonius centrispinus Engelm. Syn. Cact. 277 (1856). 
Echinocactus laticostatus Engelm. & Bigel. Pacif. R. Rep. iv, 32 (1856). 
Glaucous, depressed-globose or at length ovate or even cylindric with 
age, 4 to 20 cm. high, 6.5 to 15 em, in diameter, simple: ribs 8 to 10 
(fewer in very young specimens), often spirally arranged, the tubercles 
scarcely distinct by inconspicuous transverse grooves: spines 6 to 9, 
stout, compressed, reddish (at length ashy), recurved or sometimes 
almost straight, nearly equal, 2 to 4m. long (sometimes long and slen- 
der and almost terete, sometimes short. stout and broad); radials 5 to 
8, upper ones weaker, lowest wanting; a single stouter decurved cen- 
tral (sometimes wanting): flowers pale-rose to purple, 6 em. long or 
more: fruit red: seeds subglobose (usually looking shriveled and 
angular), rugose and minutely tuberculate, black, 2.5 to 3 mm. long. 
(TU. Cact. Mex. Bound. t. 31 and 32, figs. 1-5)—Type unknown. The 
Wright and Wislizenus specimens in Herb. Mo. Bot. Gard. are types 
of centrispinus Engelm. 
