391 
San Luis Potosi. 
Specimens examined: SAN Luis Porost (Parry & Palmer 278; 
Parry of 1878): also specimens cultivated in Hort. Jacoby in 1857; 
Hort. Dyck. in 1857; Missouri Botanic Garden in 1885, 
25. Cereus flaviflorus Engelm. MSS. 
Cylindrical, much branched at base and densely aggregated, forming 
clumps 3 to 9 dm, in diameter, branches about 30 cm. long or less and 
“5 to 5 em. in diameter: ribs few, with areolie far apart: spines very 
robust and rather irregular; radials about 10, strongly unequal; cen- 
trals 4, angled, compressed, straight, curved, or twisted: flowers yel- 
low.—Type, Gabb 10 of 1867 in Herb. Mo, Bot. Gard. 
In rocky ground, west of San Borgia, Lower California, 
Specimens examined: LOWER CALIFORNIA (Gabb 10 of 1867), 
This species closely resembles the next, and both are allied to acifer, The yellow 
flowers of this species, however, reported but not preserved by Mr. Gabb, are peculiar 
inthe group. As the material is scanty, and the differences indicated may be specitic, 
Dr. Engelmann’s separation of the three species has been preserved. 
26. Cereus sanborgianus, sp. noy. 
Cylindrical, very much branched at base and densely aggregated, 
forming clumps 4 to 9 din. in diameter, branches about 30 em, long and 
2.5 to 6 em. in diameter: ribs tuberculate, with approximate areole: 
spines pale; radials 12 to 15, very slender but rigid, 7 to 20 mm, long, 
lower longer and stouter; centrals mostly 4 (rarely 5 to 7), cruciate, 
very stout, angled and straight, 3 to 6 cm, long, the lower one longest, 
flat (2.5 mm. broad) and detlexed.—Type, Gabb 9 of 1867 in Herb. Mo. 
Bot. Gard. 
Rocky table lands south of San Borgia, Lower California. 
Specimens examined: LOWER CALIFORNIA (Gabb 9 of 1867). 
This species is indicated as new in Dr. Engelmann’s notes, but with no name. 
27. Cereus cinerascens DC. Rev. Cact. 116 (1828). 
Cylindrical, simple, erect, 20 to 25 em. high and more, 5 em. in 
diameter: ribs 7 or 8, obtuse and tuberculate, with areolie LO to 12 
min. distant: spines about 14, white, slender but rigid; radials LO (in 
young plants often 8), radiant, 12 to 18 mm. long; centrals 4 (in young 
plants often 1), erect-divergent, 2.5 cm. long, often somewhat brown- 
ish.—Type unknown. 
Southern Mexico. . 
Specimens examined: S. MEX1co (Bourgeau 303, * mountains above 
Guadalupe;” Gregg 662). 
++ +» Central spine solitary, darker, 
28. Cereus fendleri Engelm. Pl. Fend1. 50 (1849). 
Cereus fendleri pauperculus Engelm. 1. ¢. 51. 
Ovate or ovate-cylindrical, 7.5 to 20 cm. high, 5 to 7.5 cm. in diameter, 
simple or branching at base, cespitose, dark-green: ribs 9 to 12, straight 
or oblique, tubercwate, with areole 8 to 14 mm. apart: spines stout, 
very variable in length and color; radials 5 to 10 (mostly 7), straight 
