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Little Barrels 2 - Ancistrocactus, Neolloydia, Echinomastus
This
second column on the smaller relatives of the big barrel cacti
includes genera that span both sides of the Mexican/U.S. border.
These plants form small globes and little columns, sometimes
solitary, sometimes in clusters. They include a number of very
interesting species, but rarely attract a great deal of attention
to themselves, in the wild or in cultivation. Some examples
will show up in most collections of mixed varieties of cacti,
while others remain rare in cultivation and present great difficulties
for those trying to keep them alive and healthy.
Although just little plants, these cacti have created a rather
enormous amount of taxonomic controversy. The genus Ancistrocactus,
including plants formerly placed in the obsolete genus Glandulicactus,
as well as the still not forgotten Hamatocactus, is
now considered to be just a part of Sclerocactus. Regardless
of where it belongs botanically, however, the few species and
varieties of Ancistrocactus form a somewhat ecologically
coherent group, and in cultivation behave nothing at all like
the more traditionally accepted, almost ungrowable members of
Sclerocactus. In contrast, ancistrocacti tend to be
reasonably easy to grow. Ancistrocactus wrightii, (perhaps
better thought of as Ancistroactus uncinatus ssp. wrightii)
probably the most frequently encountered in the trade, forms
a smallish globe, several inches tall and wide, with deep, somewhat
undulating ribs. It grows in southwest Texas and adjacent Mexico.
Its rather blue-green body remains largely visible beneath its
somewhat raggedy spine clusters, marked by one longer, more-or-less
upward growing spine, but the plant itself remains difficult
to see as typically it hides amid sparse tufted grasses in the
spaces between rocks. When in flower, its purple-red blossoms
make it easier to find, but even then it doesn’t really
draw human-sized attention to itself. Ancistrocactus
uncinatus, from north-east Mexico, grows into a larger
plant, up to a foot tall, with more central spines, more symmetrically
arrayed and better suited for defense than concealment. This
species may grow completely exposed and out in the open, often
in considerably bleaker places than its more northern-growing
relative. Ancistrocactus scheerii, with a pleasing
symmetry to its arrangement both of radial spines and its mix
of upward and downward facing centrals, resembles its Sclerocactus relatives more than the other species. Its preferred habitat,
however, the dry scrubby hills and flats of the Rio Grande valley
area in Texas and the “Tamaulipan thorn scrub” that
once covered much of north-eastern coastal Mexico east of the
Sierra Madre mountains, receives enough water to keep its cultural
needs simple in comparison with southwestern Sclerocactus.
Most of the few remaining species assigned to the genus occupy
extremely restricted habitats in nature, and still are scarce
in cultivation. The very rare Ancistrocactus tobuschii,
a small, sometimes clumping plant with a tangle of curving central
spines and bright yellow flowers grows in a few spots on the
Edwards Plateau, in the central-west Texan hill country. It’s
also considered a subspecies of the more widely distributed A. brevihamatus, a slightly larger, usually solitary
plant, with less tangled-looking central spines and greenish-purple
flowers. A. megarhizus (regarded as just a form of
A. scheerii), is another quite distinct and very rare
plant, with a tuberous root, strongly hooked central spines,
and a somewhat unfortunate propensity for rotting off in winter.
It comes from near the Mexican town of Tula, situated along
the species rich eastern edge of the Sierra Madre Oriental,
and home to several other extremely rare, fascinating cacti.
Presently reduced to just two official species, the plants of Neolloydia show a great deal of variety within their
limited taxonomic domain. One species, Neolloydia conoides,
grows over a tremendous range, from just east of the Big Bend
region of Texas hundreds of miles south through eastern Mexico.
Often quite abundant within its range, N. conoides forms small
or medium clusters of little domed cylinders, rarely more than
six or seven inches high and two inches in diameter. They can
be more or less densely covered by their spine clusters, and
beneath their spines their epidermis ranges from pale, almost
whitish green, to very dark green with a brownish tinge. Spines,
too, can range from almost black to silvery-white. Most forms
have several prominent central spines, up to over an inch long,
but some forms, with no central spines, and radial spines arranged
in elongated little starbursts, look distinctly, attractively
different. Another form, smaller than most, with short centrals
and similarly symmetrical arrays of radial spines, was known
as Neolloydia grandiflora because of its proportionately
very large, brilliant magenta flowers. In contrast to N. conoides,
N. matehualensis (from near the Chihuahuan Desert town
of Matehuala) has a very restricted range. N. matahualensis resembles typical longish spined forms of its highly variable
relative, but its peculiar (though not particularly attractive)
bluish gray epidermis makes it easy to recognize. In some specimens,
at least, the central spines detach under the least pressure,
but lacking hooks, they simply fall off rather than work their
way into what (or whom) ever has disturbed them.
Like so many of these plants, the third genus of these little
barrels has been through the taxonomic mill. Various species
of Echinomastus have been called Sclerocactus,
Turbinicarpus, Pediocactus, or Thelocactus,
while the whole genus has been submerged at times into Neolloydia
or a very expanded Echinocactus. The plants, perhaps
oddly enough, have a quite distinctive look, and the only other
cactus they’re likely to be confused with in the field
(when not in flower) is Coryphantha. They make small
to medium sized, densely spined domes, often with an abruptly
tapering top, not too unlike Coryphantha (or Escobaria…)
vivipara. One species, Echinomastus intertextus, has
a fairly wide distribution from the farthest western outliers
of the Chihuahuan Desert ecosystem in southeast Arizona, through
southern New Mexico, western Texas, and a good ways into those
parts of Mexico directly south of those states. Its good-sized
apical flowers with white petals and either green or bright
pink stigmas, immediately distinguish E. intertextus
from those species that rather resemble it in body shape. The
first E. intertextus I saw confused me for a while,
as something too exotic to be growing in the good old U.S.A.
In the right parts of New Mexico, however, they’re not
that uncommon. Another species, the very attractive, somewhat
larger (to almost ten inches tall) E. johnsonii, actually
makes it as far west as California, in the high altitude, extremely
arid, blazing hot to sub-freezing hills of Inyo County. The
rest of the genus lives farther east, from southwest Texas down
into the Chihuahuan Desert regions of Mexico. Many of these
are very attractive plants, such as Echinomastus maripoensis,
a limestone dweller in a few places in and around Big Bend National
Park and across the river in Mexico. This small plant has a
dense covering of pure white radial spines and thin black up-pointing
centrals for contrast. E. unguispinus, and especially
the particularly dense and thick spined form called E. lauii,
from the opposite end of the range, in San Luis Potosi and Zacatecas
states, has a dense covering of beautifully arrayed, closely
held, thick, somewhat glassy spines that can look like fancy
basketry. Typically just a bit larger than the three inch E.
mariposensis, sometimes specimens of E. unguispinus
may reach more than eight inches in diameter. The remaining
species more-or less resemble smaller versions of E. intertextus,
and include highly endemic species such as the Texan E.
warnockii, and the rare Arizonan E. erectocentrus.
Unfortunately Echinomastus, probably the most attractive
of the three genera, is by far the most difficult to cultivate.
Plants need the brightest light obtainable and absolutely won’t
tolerate excess humidity or water at the wrong times. Species
such as E. mariposensis and E. unguispinus
probably do best in very alkaline or gypsiferous soils, and
none of the species should have much if any organic matter in
their soil mix. E. unguispinus has an odd growth cycle,
sometimes beginning quite early in the year and shutting down
equally early. Perhaps the best way to grow it is to water it
when it starts actively growing and dry it off as soon as it
stops, even if that means a many month long dry period. E.
johnsonii, with a preference for cold winter nights and
effectively zero humidity may be essentially impossible to grow
in our area, and may also partake in the common Mojave Desert
and Great Basin dweller habit of almost no resistance to bacteria
and fungi. The other species are simply extremely difficult.
In contrast, the species of Neolloydia aren’t particularly
hard to grow, though they aren’t very easy to flower here.
Again, very bright light, a mostly inorganic, rapid draining
soil, and more-or-less complete dryness during the winter will
prove successful with them, followed by water on a weekly basis
once it warms up. Much the same holds true for Ancistrocactus,
although a little more care is called for for those with tuberous
roots.
Along with Thelocactus and Gymnocactus from
last month’s column, these small members of the barrel
cactus group include some of the most interesting, and in many
ways most attractive members of the cactus family. In culture
they range from very easy to almost impossible, and so can provide
a challenge to everyone from beginning growers to advanced collectors.
The Garden has some very nice Gymnocactus as well as
some Neolloydia and a few Echinomastus species.
From time to time we may offer some examples from this group
for sale. |
