Compact and small with
David Van Langen,
Notes: Plants from this
population have long
tuberous roots and are covered in
are really very nice!! they are very
cold hardy and stays fairly
small and compact.
plant up to 12cm tall, forming low prostrate clumps up to 2m in
Segments are round to obovate,
5-10cm long, 5-6 cm wide, to 1.2 cm thick. Cladodes elongate conical,
to 7.5 mm long. wrinkled under very dry or cold conditions.
Yellow or brown, to 3 mm long.
five spines from the upper areoles, 2.5 to 6cm long, grey or
acicular and downwards pointing
Large tuberous and fleshy.
Yellow with red bases
to reddish, appear on early June , 5-6 cm in diameter and long.
Obovoid narrow and smooth, purple or reddish purple at
maturity, fleshy, 2.5-4 cm long, 2.5-3cm in diameter flattened and
Seeds: Tan to grey, 5mm in diameter
varieties are recognized:
has only moderately
stem segments that may reach 10 cm in length and diameter and
basically yellow flowers.
Var. pottsii (Opuntia balliii) has very
glaucous compact stem
segments reaching 5-6 cm in length and
diameter. It is easily distinguished from other varieties of
O. macrorhiza by its red flowers (as opposed to yellow),
and very slender spines. This variety is thought by some experts
to deserve specific (species)
(Salm-Dyck) L.D. Benson
in: The cacti of Arizona 20, 1969
Origin: Widespread In Midwest and south-western United
States and northern Mexico, ranging from Texas to Arizona and New
Mexico. (Colorado, Utah, Wyoming, South Dakota, Nebraska, and Missouri)
Habitat: Grows on loam or rocky, sandy
places at an elevation of 800 to 2200 m
Conservation status: Listed in
CITES appendix 2.
Common Names include:
refers to a Greek name used by Pliny for a diverse plant which grew in
the region of the town of Opus in Greece.
species name "macrorhiza" derives from
Greek adjective “macros (μακρος)”
meaning “large, long, tall, high, deep, far,”,
and the Greek word “rhiza (ριζα)”meaning
“root, stem, origin” ( The specific name implies:
" large rooted ").
variety name "pottsii" has been created in honour of
"John Potts" manager of a mine in Ciudad Chihuahua who collected
cacti for the the prince Salm-Dyck.
- O. ballii
in: Contributions from the
U. S. National
Herbarium 13 (9): 309, t. 64, 1911
- O. pottsii Salm-Dyck
in: Cacteae in Horto Dyckensi Cultae [ed. 1849] 236,
macrorhiza Engelmann 1850,
Journal of Natural History 6:
mesacantha Raf. var. macrorhiza
(Engelm.) J.M.Coult., 1896
compressa (Salisb.) Macbr. var. macrorhiza
(Engelm.) L.D.Benson, 1944
- O. tortispina Engelm.
& Bigelow, 1856
- O. sphaerocarpa
Engelm. & Bigelow 1856
- O. plumbea
- O. delicata
- O. setispina
Engelm ex Salm-Dyck. 1850
- O. tenuispina
- O. filipendula
cymochila Engelm. y Bigelow, 1856
compressa J.F.Macbr. var. grandiflora (Engelm.) Weniger
compressa J.F.Macbr. var. stenochila (Engelm.) Weniger
Cultivation: A quite cold tolerant plant, it can succeed outdoors. Requires a sandy
or very well-drained soil . Prefers a
alkaline soil. Plants
must be kept rather dry in the winter but they like a reasonable supply
of water in the growing season. A position at the base of a south-facing
wall or somewhere that can be protected from winter rain is best for
this plant. Requires plenty of sun. Plants endure considerable abandon.
Photo of conspecific taxa, varieties, forms and
cultivars of plants belonging to the
Opuntia humifusa (compressa)
has lots of synonyms
like many other cacti) whit several controversial varieties and subspecies
and comprises a multitude of different forms, but where each form
is linked to others by populations of plants with intermediate