16 THE CACTACEAE. 
_> 18. Echinocereus subinermis Salm-Dyck in Seemann, Bot. Herald 291. 1856. 
_>Cereus subinermis Hemsley, Biol. Contr. Amer. Bot. 1: 546. 1880. 
At first simple, 10 to 12 cm. high, afterwards a little branching at base, when young pale green, 
afterwards bluish and finally darker green, erect; ribs 5 to 8, broad, somewhat sinuate; spines all 
radial, small, conic, 1 to 2 mm. long, yellow, 3 or 4, deciduous; flowers large, 5 to 7 cm. long, yellow; 
perianth-segments oblanceolate, acute; spines of areoles on ovary and flower-tube short, white; fruit 
not known. 
Type locality: Near Chihuahua, Mexico. 
Distribution: Northern Mexico. 
This species was introduced into Europe in 1845. It recently flowered in Germany. 
We have studied a plant sent from Berlin to the New York Botanical Garden, in 1902, 
which died before blooming. This plant is the least armed of the genus. 
Illustrations: Blihende Kakteen 1: pl. 3; Monatsschr. Kakteenk. 26: 99. 
Figure 15 is copied from the first illustration cited above. 
19. Echinocereus luteus Britton and Rose, 
Contr. U. S. Nat. Herb. 16: 239. 1913. 
Stem short to elongated,* sometimes 
branching near base, bluish green, more or less 
purplish, 8 or 9-ribbed; ribs rather thin, barely 
undulate, rounded; areoles small, 10 to 12 mm. 
apart; spines small, the radials 6 to 8, unequal, 
2 to 8 mm. long, widely spreading, white with 
darker tips; central spine single, porrect; flowers 
on each rib appearing near top of plant and 
from second or third areole; flower-buds acute, 
reddish, covered with long, brownish bristles; 
areoles on ovary and flower-tube bearing white 
wool and light-colored spines with dark tips; 
flowers pale yellow, delicately sweet-scented, 7 
cm. long, including the ovary; outer perianth- 
segments’ streaked with red; inner perianth- 
segments lemon-yellow, oblanceolate, acute; 
filaments light yellow. 
Type locality: Above Alamos, Sonora, 
Mexico. 
Distribution: Western Mexico. . | eee aoe 
Illustration: Contr. U. S. Nat. Herb. _(———= ———— 
16: pl. 67. Fic. 15.—Echinocereus subinermis. 
Figure 16 is from a photograph of the type specimen. 
20. Echinocereus chloranthus (Engelmann) Riimpler in Férster, Handb. Cact. ed. 2. 814. 1885. 
Cereus chloranthus Engelmann, Proc. Amer. Acad. 3: 278. 1856. 
Cylindric, usually simple, 8 to 1 5 cm. lon 
. ’ 9 . g; 
hidden by the densely set spines; areoles nearly 
3 Or 4, not angled, in a vertical row, One much 
flowers yellowish green, 2 cm. long; fruit small, n 
covered with small bristly spines: se 
5 to 7 cm. in diameter; ribs about 13, often nearly 
circular; radial spines several, spreading; centrals 
more elongated than the others, 2 to 3 cm. long; 
early globular, 5 to 10 cm. long, dark purplish red, 
eds black, dull, pitted, the hilum nearly basal, round. 
Type locality: About El Paso, Texas. 
Distribution: Western Texas, southeastern N 
This species is somewhat like Echinocereus viridiflorus, having similar small flowers. 
It is usually more elongated, with lon i i 
; ger central spines and with th 
lower down on the plant, generally below the middle. ™ © showers appears 
ew Mexico, and northern Mexico. 
*Sefj : 
fior Ortega has sent us an unusual specimen, 2 dm. high, from Mazatlan (exact locality not given). 
Sh ARBRE Biichoh a 
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