46 UNITED STATES AND MEXICAN BOUNDARY. 
The habit of the two species, the only ones yet known, is entirely that of the next subgenus; 
but the small flower (less than 1 inch in diameter) has numerous very small and narrow petals, 
and few and acute stigmata. O. grandis, the only other species known, has 2 or 3 stigmata, and 
O. stenopetala only one stigma. I must remark here, that all the ovarial have opened contained 
no ovules and not even a cavity. May not the acute single style (an unique and anomalous case 
in this family) be in some connexion with this sterility, and may these flowers not be abortive 
or staminate forms ? 
1. O. sTENOPETALA (sp. nov.): prostrata ; articulis magnis crassis ; pulvillis ad marginem con- 
fertissimis fusco-setulosis ; aculeis sub-3 compressis ancipitibus curvato-deflexis seu patulis, 
adjectis seepe 1-3 minoribus, omnibus atrofuscis; floribus ex areolis fulvo-villosis; ovari 
obconici tuberculati pulvillis 30-40 confertis albido-tomentosis setosis ; sepalis tubi -petalisque 
sub-25 lineari-subulatis acuminatis aristatis aurantiacis erecto-patulis ; imo tubo nudo; stylo 
medio globoso-ventricoso apice indiviso acuto staminibus sub-breviore. (‘Tab. LXVI.) 
Common on the battle-field of Buena Vista, south of Saltillo, Mexico, Dr. J. Gregg, 1848: 
fi. July.—The specimens before me consist of dried segments of joints, bearing flowers ; joints 
apparently large, perhaps 7 or 8 inches in diameter, pulvilli about 1j or 1} inch apart on the 
surface, but much crowded towards the edges, with much dirty-white wool, short dark brown 
bristles, and very dark, almost black, spines, lighter at the tip. The stouter spines 14-2 inches 
long, flat on the upper, rounded on the lower surface, often much curved. Floriferous pulvilli 
very woolly ; ovary about 9 lines long, leaves (or sepals) on the tubercles deciduous, very slender, 
"2-24 lines long ; sepals and petals 4-6 lines long, not more than one line broad at base, very. 
slenderly acuminate, fleshy ; sepals greenish-red ; petals orange. Stamens numerous, half as 
long as the petals ; style very much inflated in the middle, and to all appearances (I have care- 
milly examined about six flowers) with a single pointed stigma. No fruit or seed was obtained, 
nor is it probable that these flowers would have ripened fruit, as no ovula could be found. Can- 
not this curious plant be obtained living? It is interesting to find in the Mexican 0. grandis, 
mentioned above, (which has long been cultivated in European gardens, but has only lately, for 
the first time, flowered in Prince Salm’s collection ») 4 very similar species, confirming this sub- 
genus; this is an erect plant, with smaller joints, two white spines on the pulvilli, and 2 or 3 
acute stigmata, 
Sur pURENETERETeroecaneapwemecmn nr cctaraceecs rng ree RE vel A | Os 
usually, although not in every species, present, bristles are almost invariably found on each pulvillus, usually small, (less than 
lines long, sometimes longer) and very numerous, mixed with soft wool. These bristles are extremely sharp and barbed 
backward, like the spines, and are loosely attached at their insertion ; consequently, when touched, they come off from the plant 
on adhere most annoyingly to the skin or orem peer the sake aculeifera and the areola florifera are united in this genus 
0 cular or blong pulvillus in the axil of the deciduous leaf. The spines occupy the lower, and the bristles the u r part 
of this pulvillus; between the bristles, and surrounded by them, and always above the me the youriy shoots or flowers seattle 
These bristles correspond with the bristles and wool in the axils of umamillarie, and with the tomentum of the floriferou 
— a — Echinocactus, but are quite distinct, morphologically, from the spines themselves. In Eumamillaria 
lori a : tirely separate ; in Coryphantha they are united by along groove; in Echinocactus by 
a short one, or are quite contiguous, although always distinct; in Cereus we do not observe a persistent florifé bi 
flower, as well as the young bud, bursts the epidermis above 
is formed and continues till soon after the fall of the fruit, when it gradually disappears. 
occurs only on the fully developed part of the plant, capable of bearing flowers, 
part is the spiniferous, and in its upper part the floriferous areola combined, is t 
ger and more numerous, and in many species the spines 
bristles, indicating a low degree of continued vegeta- 
