395 
ward into New Mexico, where it was originally discovered in the high 
mountains about Santa Fe. 
Specimens examined: TEXAS ( Wislizenus 510 of 1846): NEw MExIco 
(Wislizenus of 1846; Fendler 274 of 1847; Bigelow of 1853; Rothrock 39; 
Broadhead of 1880; Engelmann of 1881; Lt. MeCauley 574, 575): also 
cultivated in Mo. Bot. Gard. in 1863. 
35. Cereus hexaedrus [nvelm. Syn. Cact. 285 (1856). 
Ovate, 10 to 15 em, high, 5 to 6 cm. in diameter, simple or sparingly 
branched at base: ribs 6, obtuse, somewhat interrupted, with wide 
shallow groove and areolw 12 to 16 mm. apart: spines straight, angu- 
lar, rigid from a bulbous base, but. slender; radials 5 to 7 (mostly 6), 
yellowish-red, lower shorter (10 to 20 mm.), upper often stouter and 
darker, 16 to 30 mm. long; central solitary, a little stouter, acutely 
angled, 24 to 30 mm. long, often wanting: flowers and fruit unknown. 
(/U. Pacif. R. Rep. iv, t. 5, f. 1)—Type, Bigelow of 1853 in Herb. Mo. 
Bot. Gard. 
On sandy hills, under cedars, about 15 miles west of Zuni. New 
Mexico; apparently not discovered since. 
Specimens examined: NEw MExtco ( Bigelow of 1853), 
Allied to paucispinus, but distinguished by its slender and angular spines. 
++ ++ Ribs 8 to 13: central spines 2 to 7 (1 in octacanthus) 
36. Cereus octacanthus (Muhlenpf.). 
Echinopsis octacantha Muhlenpf. Alle. Gart. Zeit. xvi, 19 (1848). 
Cereus roemeri Engelm. Pl. Fendl. 50 (1849), not Muhlenpf. (1848). 
Ovate, bright-green, 7.5 to 10 em. high, 3.5 to 6 em. in diameter, 
densely cespitose (often 5 to 12 heads from the same base), sometimes 
simple: ribs 7 to 9, tubereulate, obtuse, with areole 8 to 16 mm. apart: 
spines stout, terete, white (or yellowish when young) at length ashy; 
radials 7 or 8, 10 to 24 mm, long, upper a little shorter, lateral longest; 
central solitary, stouter, porrect, 20 to 30 mm. long: flower red, 5 em. 
long and 2.5 em. wide, red: fruit and seed unknown.—Type unknown. 
From extreme southwestern Texas, northward and westward through 
New Mexico into Utah. 
Specimens examined: TEXAS (Hvans of 1891, about El Paso): NEw 
Mexico (Fendler 272 of 1846, in part): Uran (Mrs. Thompson): also 
cultivated in Mo. Bot. Gard. from Herb. Torr. 
37. Cereus roemeri Muhlenpf. Allg. Gart. Zeit. xvi, 19 (1848), not Engelm. (1849). 
Cereus pheniceus conoideus Engelm, Syn. Cact, 284 (1856). 
Cereus conoidens Engelm, Pacif, R. Rep. iv, 36 (1856). 
Ovate, conoid-acutish at apex, 7.5 to 10 em, high, sparingly branched 
at base: ribs 9 to 11, obtuse, tuberculate, with areole 8 to 12 mm. 
apart: spines whitish or straw-color, translucent, with bulbous base; 
radials 8 to 12, slender and rigid, straightish, upper 4 to 10 mm. long, 
lateral 12 to 30 mm.; centrals 3 to 5 (usually 4), very bulbous, upper 
hardly longer than lateral radials, lowest quadrangular, often dusky 
26 — 
