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Big Barrels
A man, his clothes in tatters, drags himself painfully across
the sand when, to his amazement, he comes upon a peculiar looking,
spiny, cylindrical object, perhaps equipped with a handy faucet.
This classic cartoon image has undoubtedly introduced many people
to the idea of the desert, and in particular, to that living
drinking-fountain, the barrel cactus. His strength and spirits
revived, our adventurer can now move forward and begin to build
a golf-course or a casino, or some other symbol of the modern
desert.
Just what are these so-called barrel cacti, a few curious types
might ask? Are they really filled almost to bursting with pure,
fresh water? Do they exist in a land other than that of the
cartoon? Well, no, they’re not really filled with water,
and yes, they most certainly do exist, in the arid landscapes
of the American southwest, Baja California, and the Mexican
mainland. Three and a half dozen cylindrical, distinctly ribbed
plant species colloquially called barrel cacti belong to the
rather similar looking, related genera Echinocactus
and Ferocactus (each now including species once considered
separate genera).
All these plants grow into a cylindrical shape, quite small
in a few cases, squat and pulled low into the ground in some
others, as much as eight or nine feet tall and three feet thick
in the largest forms. Many species remain solitary, others offset
sparsely from the base, and a relatively few species form large,
many-headed clumps. In most cases the plants bear extremely
thick, heavy spines, varying from short to very long according
to species, and often with a curved central spine.
The
dense woolly crowns of echinocacti set them apart from their
Ferocactus cousins. In the United States, ferocacti
generally grow in particularly arid sections of the Sonoran
and Mojave deserts in southeast California, Arizona and parts
of New Mexico. Our two native echinocacti live either in the
higher elevations of the Mojave Desert, or well to the south,
in far southern Texas, and the narrow extensions of the Chihuahuan
Desert into Arizona and New Mexico. The two sunken genera complicate
matters, as both of them come from Texas, where Homalocephala
texensis is now Echinocactus texensis, and
Hamatocactus hamatacanthus has turned into a Ferocactus,
with the other members of its erstwhile genus scattered to the
four winds, taxonomically speaking. In Mexico ferocacti and
echinocacti grow over much of the country, though ferocacti
have a somewhat more western distribution. Baja California,
in particular, the home to a large number of interesting ferocacti,
has no echinocacti at all.
The
six species of Echinocactus have an odd, somewhat disrupted
distribution. The largest species, E. platyacanthus, “the Giant Visnaga,” a tall growing, extremely massive
cactus that ranges over much of northeast and central Mexico,
can dominate a landscape because of its large size and impressive
bulk. The plants (which have had several other names assigned
to them, including Echinocactus ingens and Echinocactus
grandis) often have a somewhat sway-backed, saddle-shaped
apex, densely covered in white wool, where their yellow flowers
emerge. Possibly the most common cactus in cultivation, the “Golden Barrel,” Echinocactus grusonii,
admired for its symmetrical, round shape and bright yellow spines,
in many ways seems like a somewhat smaller, less robust giant
visnaga (or “bisnaga,” the generic term in Mexico
for any barrel-type cactus). Curiously for such a frequently
encountered plant in horticulture, its native habitat was quite
small, the sloping sides of a series of canyons in Queretaro
state, now almost completely submerged by a reservoir, and the
species is almost extinct in the wild.
A
third interesting species, Echinocactus horizonthalonius,
comes from southern Texas and adjacent northeast Mexico, with
a very limited extension into a bit of southern Arizona as well.
Distinguished by its distinctly gray epidermis, it also produces
a white woolly flowering top at its center. Its bright magenta
flowers stand out dramatically against the arid white limestone
hills where it often lives. E. texensis, sometime called
the “Texas horse crippler” grows fairly low to the
ground, where its thick, sharp, but fairly short spines could
conceivably injure livestock (or anyone who stepped on one).
Rarely reaching over a foot in diameter, or more than six inches
in height, it grows in brush or grassland in much of east Texas,
north to Oklahoma and south to northeast Mexico. In contrast
to these generally solitary species, Echinocactus polycephalus
(as its name implies) forms many-headed clumps of smallish barrels,
densely covered with thick spines, either bright yellow or pink
when young, aging to gray. E. polycephalus is a plant
of the interior American deserts, growing along the Colorado
River both west and east of the Grand Canyon, and stretching
northwest to Death Valley and the high desert of Inyo County
in California. An attractive plant with its compact size and
colorful spines, E. polycephalus, unfortunately, is
just about impossible to grow in cultivation, at best maintaining
its form for a number of years after death until it finally
collapses and dries up. Echinocactus horizonthalonius,
although not as difficult as E. polycephalus, is also
extremely hard to keep alive for more than a few years, at least
in climates that share our wet, humid winters. Conversely, the
other echinocacti grow readily in cultivation, without much
fuss at all, and both the golden barrel and the giant visnaga
will do well outdoors given good drainage. In containers, a
standard, quick draining succulent soil mix, lots of sun, water
once a week in the warm months, and perhaps every month or two
in winter, will keep them thriving for years.
Almost
all of the two and a half dozen species of Ferocactus also behave well in cultivation. Their bright flowers, in colors
from yellow, through orange and red, to purple, poke out of
their apices; unfortunately most must be large plants before
they’ll flower. A number of them are familiar sights to
anyone who’s traveled to Palm Springs or Tucson, including Ferocactus cylindraceus (the currently accepted name
for the more familiar F. acanthodes) and Ferocactus
wislizeni, tall growing, usually solitary barrels, with
thick, somewhat curved spines that often glow bright red when
young. Whether medium sized or large, most of the species endemic
to Baja California and its neighboring islands share this general
form as well. Ferocactus townsendianus, with a slightly
glaucous body and dense spination, Ferocactus gracilis
and Ferocactus emoryi all are typical attractive Baja
species. So are Ferocactus cylindraceus spp. tortulispinus
(formerly F. tortulispinus), with strange spiraling,
twisting spines, and Ferocactus rectispinus (now considered
Ferocactus emoryi ssp. rectispinus), with razor-sharp
central spines up to ten inches long, each of them among the
most fiercely armed of this generally fierce (“fero” means fierce) genus. Ferocactus pilosus (frequently
called F. stainesii), from north-east and central Mexico
and up to nine feet tall, with several subsidiary barrels growing
from the main one, with deep green bodies densely covered with
bright red spines up its entire length, may be the most spectacular
of the species. Another plant from the islands off Baja, Ferocactus
diguetii turns from a barrel into a column, over twelve
feet tall and two feet thick.
Moving
from big to small, coastal San Diego County still has a few
Ferocactus viridescens, rarely more than a foot tall
or in diameter, with a range extending down the Pacific coast
into Baja. A little farther south down the Baja coast the quite
limited habitat of Ferocactus fordii begins. A bit
smaller than F. viridescens, this species will produce
its pretty magenta flowers in a six or seven inch pot. Ferocactus
latispinus, from central Mexico, will become somewhat larger,
but it’s very easy to grow and with its thick, fairly
short reddish spines, it makes a nice container specimen. With
bright yellow spines and a distinctive blue-gray body, Ferocactus
glaucescens stands out from the other species. Though it
can reach over eighteen inches in diameter, it will nonetheless
flower perfectly well in an eight inch pot. Finally, Ferocactus
hamatacanthus (formerly Hamatocactus), also will
flower in a medium sized container. It has unusually narrow
spines for a Ferocactus that sometimes twist as well,
and though it rarely becomes more than a solitary foot and a
half tall cylinder in the extremely arid rocky outcrops that
it favors in southern Texas, a couple of hundred miles south,
in Coahuila, it sometimes grows in flat, almost barren dry lake
beds where it produces five or six stemmed clusters a yard high.
Many
ferocacti will grow outdoors if given very good drainage. Even
our coldest temperatures rarely bother them, but the more arid-growing
types will do better if given extra-good drainage and protection
from the rain. The plants from northern Baja California and
San Diego may grow through the winter (though our rainfall is
so much higher than that of their habitats that their survival
outdoors in wet or cold years can’t be guaranteed), and
the plants on the whole can withstand a bit more winter water
than most cacti. Still, once a month (or less) is a good bet
for the cold time of year, once a week when it gets warm unless
they’re obviously dormant. In the wild their ribs will
expand and contract like an accordion according to the amount
of liquid they hold, but this liquid exists in the form of gooey
pulp, not at all accommodating to a faucet.
The
Garden has a good collection of barrel cacti, with some nice
old specimens a prominent feature of the New World Desert area,
and more variety inside the Arid House. We generally have some
to sell from time to time. |
