Echinocactus horizonthalonius var. nicholii
Arizona Turk's Head, Nichol's Turk's Head Cactus

Nichol's Turks Head Cactus is an isolated Southern Arizona population that differs from the common variety
in its disjunct and highly restricted range, large size and robust spines, elongated shape (not flattened at maturity),
and habit of producing offsets or vegetative buds (small plants growing at the base of an old one).

The common variety found in Texas and Mexico (but not Arizona) is
Echinocactus horizonthalonius var. horizonthalonius.
Common names:  Blue Barrel, Devil's Head, Horse Crippler
It is smaller, round or slightly flattened in shape, and has more delicate spines.  It grows singly and does not produce buds.

Nichol's Turks Head is unique and unmistakable within its range.  Other BARREL CACTI  that grow with it
are dark green, much larger, have more than 8 ribs, have red and/or yellow spines, and have yellow, orange, or red flowers.

Federal Threatened and Endangered Species status:
E. h. var. nicholii is listed as endangered.
THREATS: Primarily collection and offroad vehicle use; also grazing and (potentially) development.

Arizona Rare Cactus Photos

This cactus grows in limestone gravel on flat areas or gentle slopes, and occasionally in cracks in the rock.

There are ALWAYS 8 RIBS, which may be straight or twisted into a slight spiral.
Spines are white, gray, purple, and pink, and are flat or nearly round.

Anomalous plant with unusually broad, flat, dark spines.

Vegetative buds on old plants.  This slow-growing species is long-lived for its size - 50 years or more!

ODDBALLS:  Left: This polycephalic plant has many small heads on an ordinary base,
a growth habit that is rare in this species but not in the Arizona barrel, Ferocactus wislizenii.
Right:  There are 8 very thin EXTRA RIBS on this unique plant.

 Even the youngest plants have 8 ribs and the distinctive blue-green color.

Flower buds form in spring but remain hidden under protective "wool" until the summer monsoon thunderstorms.
A few days after the first rain, nearly all plants bloom at once - often on the same day as the Pima Pineapple Cactus!
Flowers are uniformly bright magenta pink and last for only one day.

Unusually early flower blooming after a spring storm, April 26, 2015.


E. horizonthalonius var. horizonthalonius
PLUS links to more 3-D cactus photos!