Opuntia ×spinosibacca

M. S. Anthony

Amer. Midl. Naturalist 55: 246, fig. 22. 1956.

Synonyms: Opuntia phaeacantha var. spinosibacca (M. S. Anthony) L. D. Benson
Treatment appears in FNA Volume 4. Treatment on page 140. Mentioned on page 129, 139.

Shrubs or small trees, erect, to 1.5 m. Stem segments not easily detached, green, often purple near areoles, flattened, obovate to ovate, 10–25 × 7.5–11 cm, ± tuberculate, glabrous, glaucous; areoles 4–5 per diagonal row across midstem segment, subcircular to oblong, 5–6 mm diam.; wool tan, aging blackish. Spines 1–5 (–8) per areole, at most areoles, spreading, white with red base, becoming dark redbrown with pale tips, aging gray, stout, usually curved, elliptic in cross-section, longest to 70 mm. Glochids closely spaced in crescent at adaxial edge of areole, along margins of areoles, and in subapical tuft, yellow, to 4 mm. Flowers: inner tepals deep yellow with red basal portions, to 35 mm; filaments yellow; anthers pale-yellow; style cream; stigma lobes yellow-green. Fruits often sterile, sometimes proliferating, yellow to red, ovoid to obconic, 28–32 × 13–22 mm, usually fleshy, becoming dry, tuberculate, glabrous; areoles 20–30, distal areoles bearing 1–4 redbrown and white spines, to 25 mm. Seeds few, tan, subcircular to irregularly shaped, 4–5 mm diam.; girdle protruding to 1 mm. 2n = 44.


Phenology: Flowering spring (Apr–May).
Habitat: Limestone hills, slopes
Elevation: 900 m

Discussion

Opuntia ×spinosibacca apparently originated from hybridization between the dry-fruited, diploid O. aureispina and the fleshy-fruited, hexaploid O. phaeacantha (or O. camanchica Engelmann & J. M. Bigelow). The nothospecies is restricted to the vicinity of Big Bend National Park, Texas. A very similar hybrid, O. ×rooneyi M. P. Griffith (O. aureispina × O. macrocentra, both diploids) is known fom the same region. The hybrids differ in spine number and distribution. Opuntia ×rooneyi has 2–3 central spines to 40–50 mm and 1–4 radial spines to 20 mm, the spines concentrated in the distal 2/3 of the stem segments. Opuntia ×spinosibacca has 2–5 central spines to 70 mm and 0 radial spines, the spines in nearly all areoles of the stem segments.

Selected References

None.

Lower Taxa

None.
... more about "Opuntia ×spinosibacca"
0 cm0 mm <br />0 m <br /> (7 cm70 mm <br />0.07 m <br />) +
pale-yellow +
cushionlike +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
deciduous +  and persistent +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
20 +  and 30 +
subcircular +  and oblong +
0.1 cm1 mm <br />0.001 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Donald J. Pinkava +
M. S. Anthony +
proliferating +
flattened +  and cylindric +
0 cm0 mm <br />0 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
15 cm150 mm <br />0.15 m <br /> (30 cm300 mm <br />0.3 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (15 cm150 mm <br />0.15 m <br />) +
spineless +  and stipitate +
burlike +  and spiny +
straight +
indehiscent +
persistent +, long +  and deciduous +
28mm;32mm +
proliferating +
tuberculate +
ovoid +  and obconic +
1.3 cm13 mm <br />0.013 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0 cm0 mm <br />0 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
foveolate +  and reticulate +
Limestone hills, slopes +
oblong +  and spatulate +
0 cm0 mm <br />0 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
deciduous +
flattened +  and conic +
0 cm0 mm <br />0 m <br /> (3 cm30 mm <br />0.03 m <br />) +
succulent +
tuberculate +
fluted;spheric;depressed-spheric or club-shaped +
tinged color +
open +  and simple +
sometimes covered by outgrowths of proximal portion of style base or of flower tube wall +  and open +
persistent +  and deciduous +
Flowering spring (Apr–May). +
ridgelike +  and nipple--shaped +
Amer. Midl. Naturalist +
3;2;2;30 +
tuberlike +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
subcircular;irregularly-shaped +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
not sheathed +
7.5 cm75 mm <br />0.075 m <br /> (17 cm170 mm <br />0.17 m <br />) +
white +  and redbrown +
deciduous +  and persistent +
conspicuous +
with hairlike bristles +  and setose +
1 (?) +  and 4 (?) +
terete +  and angular-flattened +
0 cm0 mm <br />0 m <br /> (7.5 cm75 mm <br />0.075 m <br />) +
hard +  and rigid +
decurrent +
winged +  and unsegmented +
tuberculate +  and smooth +
60 cm600 mm <br />0.6 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +
10 cm100 mm <br />0.1 m <br /> (25 cm250 mm <br />0.25 m <br />) +
glaucous +  and glabrous +
7.5 cm75 mm <br />0.075 m <br /> (11 cm110 mm <br />0.11 m <br />) +
segmented +
woody +  and succulent +
Opuntia phaeacantha var. spinosibacca +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Opuntia ×spinosibacca +
species +
dull +  and glossy +
segmented +
tree +  and shrub +
terrestrial;epiphytic or epipetric +
blackish +  and tan +