spinosissima is a columnar plant. It's usually solitary,
but it can form pups on
old plants. M. spinosissima is very variable because of its wide area of
origin in Mexico. The colour of the spines vary from red or rust to
Stem: Cylindrical, dark blue-green, rarely exceeding 30 cm in
height, 6 - 7 (10 cm) cm in diameter. Without latex.
Parastichy: 13 - 21
Tubercles: Ovate conical, four-sided basally. The
axil is slightly woolly.
Radial spines: 20 - 25, white, bristle-like, 4 - 6 mm long.
Central spines: 12 - 15, pinkish-white, stronger than the radials and
thicker at the base, straight, 10 - 12 mm long.
Flowers: Vivid purple/ red to deep pink, 12 mm in
length and in
diameter, encircling the columnar stems.
Blooming season: Late winter and spring,
Fruits: Purplish red or greenish.
subspecies, varieties and forms:
- The subspecies 'spinosissima' only
rarely grows higher than 30cm. It has dirty white to coppery red
spines and does not have bristles in the axils most of the time.
- The subspecies 'tepoxlana' has yellow
- The subspecies 'pilcayensis' has whiter
spines, and the stems can grow
up to 50cm long/high. It might have some
latex/bristles in the axils. The flowers are purple-pink on all subspecies