401 
min. apart: spines straight and rigid; radials 6 to 8, white, yellowish 
or blackish, the 3 highest more rigid, 16 to 20 mm. long, the lower 4 or 
5 more slender, 6 to8 mm. long; centrals 1 or 2, 12 to 25 mm. long.—Type 
unknown. 
A common and widely distributed species of the West Indies, south- 
ern Mexico, Central America, Peru, and Brazil. 
Specimens examined: Cuba ( Wright 2624). 
Avery variable species, the joints being very long and quadrangular, and ovate and 
triangular on the same plant; the areole sometimes with whitish and sometimes 
with brownish tomentnuin; the spines sometimes short and white, and sometimes 
elongated, rigid and fuscous. The north Mexican form referred to this species by 
Dr. Engelmann is Cereus princeps Pfeitt. 
50. Cereus princeps Hort. Wuerzb.; Pfeiff. Enum. 108 (1837). 
Cereus variabilis Engelm. Pl. Lindh. 205 (1850), not Pfeiff. (1837). 
Stems erect, 9 to 30 dm. high, 5 cm. in diameter, 3- or 4-angular, and 
with distant areolie: spines 4 to 6, stout and radiant, unequal, the larger 
25 to 35 min. long, the central deflexed: flower long-tubular, 17.5 to 20 
em. long, 13.5 to 15 em, broad: fruit oval, spiny, 5 to 7.5 em, long, 5 em. 
in diameter, scarlet and with luscious red pulp: seeds obliquely obovate, 
smooth and shining, 3 to 3.4 mm. long, (//l, Cact. Mex. Bound. t. 60. 
f. 5 and 6)—Type unknown. 
On the Mexican side of the lower Rio Grande. 
Specimens examined: TAMAULIPAS (St. Louis Volunteers of 1846; 
Poselger of 1850; Schott of 1853): also cultivated in Mo, Bot. Gard. in 
1849, 1859, 1867, 1870, 1871, and 1873; also in Harvard Bot. Gard. in 1872, 
Probably to be found on the Texan side of the lower Rio Grande. The young 
shoots are said to have 8 ribs and more numerous slender spines; and in some of the 
cultivated specimens the spines become much longer than in the description. 
51. Cereus palmeri Engelm. MSS. 
Stems branching, 3- or 4-angled, 12 to 15 dm, high: spinesin greenish- 
brown bunches: fruit greenish-yellow, its areole bearing 5 to 8 short 
stout spines.—Type, Palmer 70 of 1869 in Herb. Mo, Bot. Gard. 
Sonora. 
Specimens examined: SonoRA (Palmer 70 of 1869). 
This very brief and unsatisfactory diagnosis was drawn by Dr. Engelmann from a 
few scraps and notes, a diagnosis that I have no means of supplementing. Dr. 
Palmer’s notes further state that the ‘branching plant is weighed down by the heavy 
fruit.” 
++ ++ Flowers purple. 
52. Cereus striatus Brandegee, Zoe, ii, 19 (1891). 
Stems weak, quadrangular, becoming terete, very sparingly branched 
above, ash-color, about 10 dm. high and 2 to 6 mm, in diameter: ribs 
or striations 9, flat and slightly raised above the flat greener intervals, 
with areol about 6 mm. apart: spines about 9, soft, closely appressed, 
either light-colored or brown; sometimes perfectly black, 1 to 3 mm. 
long: flowers purple, 10 to 12 cm. long, the elongated tube bristly: fruit 
