CACTACEE. 21 
setting off the white membranaceous sepaloid scales. Seed 0.7-0.8 line long, remarkably 
curved and contracted at the base ; compressed, (more so in the ventral curvature,) carinate on 
the pack, tuberculate; the small circular hilum surrounded by a very tumid, smooth, and 
shining rim. Albumen large; embryo hooked, with foliaceous cotyledons. 
The Mexican EZ. uncinatus, of which I have seen spines and seeds collected by Dr. Poselger 
between Saltilloyand San Luis Potosi, and flowers found by Dr. Gregg, near Parras, has 7-8 
radial spines, the 3 lower ones hich are hooked, and 4 central ones, the lowest one flattened 
and elongated ; lower sepals 36, upper ones about 14, oblanceolate, aristate, margined ; petals 
25, linear-lanceolate, acuminate, aristate ; 8-10 stigmata; seeds 0.6-0.7 line long, very much 
compressed, curved, almost cochleate, smoothish and shining; circular hilum almost ventral ; 
albumen and embryo same as in the other. (Tab, LXXIV, fig. 9.) 
4. KE. setisprnus, E. in Pl. Lindh. Many forms have been collected by the Commission ; all — 
characterized by 13 narrowly-compressed ribs, slender flexible spines, small bright-red globose 
fruit, and globose-obovate oblique strongly tuberculated seeds, with an almost circular basilar 
hilum. The heads are globose, or usually lengthened and almost cylindrical when old, but 
sometimes depressed ; spines short or long, the central spine usually somewhat longer than the 
others, but in some specimens from the Rio Grande shorter, in others from Eagle Pass 
much longer than the others, and erect, sometimes hardly curved. Seed usually 0.6 line long ; 
in the above-mentioned specimen from Eagle Pass 0.8 line in length. The geographical range 
of this species is from the Brazos south to the Rio Grande, whence Berlandier has sent it under 
the name of Cactus bicolor, and west to near the San Pedro. 
5. E. stnvatus, Dietr. (E. setispinus, 7. sinuatus Poselg.): globosus, lete viridis; costis 13 
obliquis compressis acutatis interruptis; tuberculis breviter sulcatis; areolis orbiculatis, juni- 
oribus albo, seu griseo-villosis ; aculeis radialibus 8-12 setiformibus flexilibus, 3 inferioribus 
et 3 superioribus purpureo-fuscis rectiusculis, lateralibus 2-6 tenuioribus longioribus seepe com- 
pressis rufis seu interdum flexuosis hamatisve albidis; aculeis centralibus 4 quorum 3 supe- 
riores graciles compressi seu sub-angulati erecti plerumque recti, infimus latior compressus seu 
canaliculatus flexuosus elongatus stramineus basi purpurascens apice subhamatus ; floribus ab 
areola aculeifera paullo distantibus ; sepalis inferioribus 20-30 cordato-auriculatis, superior- 
ibus 15-20 lanceolatis basi auriculatis margine membranaceis; petalis 20-25 lanceolatis sul- 
phureis ; stylo longe supra stamina exserto; stigmatibus 8-12 apiculatis erecto-patulis; bacca 
ovata squamis 7-10 munita viridi; seminibus obovatis seu lenticularibus hilo oblongo sub- 
basilari excisis lucidis sub lente minutissime punctatis. (Tab. LX XIV, fig. 11-14.) 
On the Pecos, San Pedro, and Rio-Grande rivers, Wright, Schott.—I have above given a 
careful description of this plant, because it is so nearly allied to the foregoing and especially to 
the next species, which Dr. Poselger thinks it connects. With the former it has in common 
only the compressed ribs and the setaceous radial spines, but is*distinguished by its size, the 
central spines, the fruit, and especially the seed. From the next species, to which it much 
more closely resembles, it is distinguished by the compressed ribs, the slender radial spimes, the 
smaller number of all parts of the flower, the small fruit, and the smaller very finely punctate 
seed. My specimens are 4 or 5 inches in diameter, while Dr. Poselger’s were 8 inches thick ; 
areolz 8-10 lines apart ; 3 lower spines smooth purplish-brown, lighter at top, }-1 inch long, 
lateral spines puberulent, straw-colored, 1-1} inch long; central spines puberulent, 3 upper 
ones yellowish, generally darker at base, 13-2 inches long; lower central spine much stouter 
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