; CACTACEH OF THE BOUNDARY. 205 
IV. OPUNTIA, Tovurn., Mitx.® 
Subgen. 1. STENOPUNTIA. 
Articuli complanati. Aculei non vaginati. 
Flores parvi. Petala parva, subulata, erectiuscula (aurantiaca). 
Stigmata pauca (1-3), acuta. 
Bacca? et Semina | 
The habit of the two species — the only ones yet known — is entirely that of the next subgenus ; vl oe [46] 
small flower (less than 1 inch in diameter) has numerous very small and narrow petals, and few and a 
stigmata. 0. grandis, the only other species known, has 2 or 3 stigmata, and 0. stenopetala only one peat ef must 
remark here that all the ovaria I have opened contained no ovules, and not even a cavity. ay not the acute 
single style (an unique and anomalous case in this family) be in some connection with this sterility, and may these 
flowers not be abortive or staminate forms ¢ 
_» 1. O. STENoPETALA, sp. noy.: prostrata; articulis magnis crassis; pulvillis ad eco confertissimis fusco- 
setulosis ; aculeis sub-3 compressis ancipitibus curvato-deflexis seu oe ee adjectis sepe 1-3 minoribus, omnibus 
atrofuscis ; floribus ex areolis fulvo-villosis ; ovarii obconici tuberculati pulvillis 30-40 constants 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. eve 
CG n on the battle-field of Buena Vista, south of Saltillo, Mexico (Dr. J. Gregg, 1848). Flowers in July. — 
The Seca before me consist of dried segments of joints, bearing flowers. Toate apparently large, perhaps 
7 or 8 inches in diameter ; pulvilli about 1} or 1} inch apart on the surface, but much crowded toward the edges, with 
much dirty-white wool, short dark brown bristles, and very dark, almost black spines, lighter at the tip. The stonter 
spines 1}-2 inches long, flat on the upper, rounded on the lower surface, often much curved. Floriferous pulvilli v 
woolly ; ovary about 9 lines long ; leaves (or sepals) on the tubercles deciduous, se slender, 2-2} lines long, sepals 
and petals 4-6 lines long, not more than 1 line broad at base, very slenderly acuminate, fleshy; sepals greenish-red, 
petals orange. Stamens numerous, half as long as the petals; style very ne inflated in the middle, and to all 
appearances (I have carefully 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. Cannot this 
curious plant be obtained living? It is interesting to find in the Mexican O 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), 
a very similar species, confirming this subgenus: this is an erect plant, with smaller joints, two white spines on the 
pulvilli, and 2 or 3 acute stigmata. 
sides its strictly differential characters (namely, the ous areola in Coryphantha and Echinocactus, but are quite 
ees nalts and the flat bony seeds with large foliaceous distinct, morphologically, from the spines themselves. In 
cotyledons), this genus is distinguished from the other Cac- Eumamiliarie the aculeiferous and floriferous areole are en- 
tacee by its subterete, subulate, and deciduous leaves, and tirely at ; in tesa they are united by a long 
by its barbed spines, which I do not find in any other plant groove chinocactus by a short one, or are quite con- 
of this family. These spines render Opuntie so much more tiguons, atihoagh ae distinct ; in Cereus we do not ob- 
—< eeable and even dangerous than other Cacti. In several serve a persistent floriferous areola, — the flower, as well as 
pecies (0. frayilis, “8 Bigelovii, O. frutescens, — others) the young bud, bursts the epidermis above and close to the 
Aa joints easily separate from the stem, and adhere by their spiniferous areola, where a kind of floriferous areola is formed, 
bar s to the ron or clothes of the ati — the and continues till soon after the fall of the fruit, when it 
most annoying burs. Besides these spines, —which are usually, gradually disappears. In all these plants the floriferous areola 
altiiough not in every species, present, — bristles are almost occurs only on the fully developed part of the plant capable 
invariably found on each pulvillus, usually small (less than of bearing flowers. But in Opuntia the pulvillus (which in its 
or 2 lines long, sometimes longer), and very numerous, lower part is the spiniferous and in its upper part the florifer- 
mixed with soft wool. These bristles are extremely sharp, ous areola combined) is the same in all stages of development ; 
and barbed backward like the spines, and are loosely attached only it is smaller on the lower part of each joint, and 
at their insertion ; consequently when touched they come off fewer or o no spines, and rarely if any flowers or new 
from the plant and a ost annoyingly to the skin or shoots, while the uppermost pulvi’li have the longest and 
clothing. Both the areola aculeifera and the areola florifera most numerous spines, and bear the flowers as well as the 
are united in this genus into one circular or oblong pulvillus young branches, The pulvilli of Opuntie continue to grow 
in the axil of the deciduous leaf. The spines oceupy the year after year, and the bristles become longer and more 
lower and the bristles the upper part of this pu/vil/us ; be- ce, and in many species the spines themselves grow 
tween the bristles, and surrounded by them, and always above Sometimes new spines are developed between the 
the spines, the young shoots or flowers originate. ese eat magne a low degree of continued vegetative ac- 
bristles correspond with the bristles and wool in the axils of tivity on the rudimentary axis represented by the floriferous 
some Eumamille with the tomentum of the florifer- areola. 
