Plant Profiles - Cactaceae
ASTROPHYTUM MYRIOSTIGMA
Family: Cactaceae
Genus: Astrophytum
Species: myriostigma
Common Name: Bishop’s Cap
Recommended Temperature
Zone: USDA: 9b-10
Frost Tolerance: Hardy to 20°F (6°C) for short periods
Sun Exposure: Full sun to light
shade
Origin: Highlands of central and
northern Mexico
Cultural Practices:
If planted outdoors, sharp
drainage is important for avoiding
rot during wet winters since this
time of year is dry in its habitat.
Mealy bugs and root mealy bugs
can be a problem.
Blooming Habits:
The glossy yellow, sweet scented
flowers appear intermittently
during the summer. They are
followed by a reddish fruit, 1 inch
in diameter (2.5 cm). The plants
known as A. coahuilense have a
reddish orange throat.
Growth Habits: Columnar cactus,
up to 2 feet long (60 cm) by 8
inches in diameter (20 cm); 4 to 6
ribs (usually 5); no spines
Watering Needs: Moderate water
in summer.
Propagation: Seeds that germinate
rapidly. Some cultivars are grafted.
They take up to 6 years to bloom.
ASTROPHYTUM ORNATUM
Family: Cactaceae
Genus: Astrophytum
Species: ornatum
Recommended Temperature
Zone:
USDA: 9b-10
Frost Tolerance: Hardy to 20° F (6°C)
Heat Tolerance: Good
Sun Exposure: Full sun to light
shade
Origin: Mexico (Querétaro,
Hidalgo)
Propagation: Seeds that
germinate rapidly. Some cultivars
are grafted. They take up to 6
years to bloom.
Blooming Habits: The
Astrophytum ornatum blooms in
summer. The 2.5 inch wide
flowers (6 cm) are pale yellow
and scented. It needs to be 6
inches tall to bloom (15 cm). This
might take six years or more
depending on the length of its
growing period in your local
conditions.
Growth Habits: Solitary columnar
cactus, up to 4 feet tall (1.2 m), 6
inches in diameter (15 cm); usually
8 ribs; 1 central spine; 5 to 10
radials.
The Astrophytum ornatum is the
largest and one of the easiest to
grow of the Astrophytums. It has
5 to 8 ribs (generally 8) and
areoles have 5 to 11 brownish
yellow spines, over 1 inch long
(2.5 cm).
Watering Needs: Moderate water
in summer.
Page | 1 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
AUSTROCYLINDROPUNTIA SUBULATA
Family: Cactaceae
Genus: Austrocylindropuntia
Species: subulata
Common Name: Eve's-Pin Cactus
Culture: Austrocylindropuntia
subulata needs full sun to light
shade, with a well drained soil
mix. This cactus likes a little more
water than other cacti. Regular
watering helps to keep the leaves
from dropping.
Eve's-Pin Cactus, is a large tree-like
cactus native to the higher
elevations of Ecuador and Peru. In
nature, the cactus lives at an
elevation of 8000-12000 feet
(2400-3600 m). Round cylindrical
joints will reach up to 2 feet (60
cm) tall and 1.5-2.5 inches (4-6.5
cm) thick. Plants will reach about
13 feet (4 m) tall and 10 feet (3 m)
wide. They are easily identified by
their persistent, nearly cylindrical
leaves. Leaves will reach about 3-5
inches (7.5-13 cm) long. New
growth rarely has spines, but as
the plants age they develop 1-2, 3
inch (7.6 cm) long yellow spines
per areole. The plants are easy to
grow and are hardy in the
landscape in USDA zones 9-10.
Propagation:
Austrocylindropuntia subulata is
propagated from cuttings and
from seeds when available.
Blooming: In cultivation, the plants
rarely bloom, but when they do
the bloom the flowers are red 2-4
inches (5-10 cm) long. Blooms are
quite showy.
Page | 2 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
CEREUS HILDMANNIANUS
Family: Cactaceae
Genus: Cereus
Species: hildmannianus
Common Name: Queen of the
Night, Apple Cactus
Synonym: Cereus peruvianus
Recommended Temperature
Zone:
USDA: 9-11
Frost Tolerance: Hardy to 15°F (10°C)
Sun Exposure: Full sun
Origin: Southeastern Brazil,
northern Argentina
Watering Needs: Does best with
moderate water.
Propagation: One of the easiest
cactus to propagate by cuttings
This species is popular in
cultivation and often
encountered in southern
Californian gardens, as well as in
Phoenix. The stems have 5 to 8
narrow ribs with areoles 1-inch
apart. Depending on the variety,
the areoles are either almost
spineless or with 7 radial spines
and a central spine, measuring
around 0.4 inch long (1 cm).
Growth Habits: Columnar cactus
branching from the base, up to 30
feet tall (9 m), clump up to 15
feet in diameter (4.5 m), stems
are 5-7 inches in diameter (12-17
cm), often no spines on younger
stems, spines grow progressively
as the stem ages.
Blooming Habits: The 6-inch (15
cm), white flowers open at night
in late summer to early fall. They
are followed by large, smooth
red, egg shaped edible fruits that
split open when ripe.
CLEISTOCACTUS HYALACANTHUS
Family: Cactaceae
Genus: Cleistocactus
Species: hyalacanthus
Recommended Temperature
Zone:
USDA: 10-11
Growth Habits: Clustered erect
cylindrical stems to 6 feet tall
densely clad in bristly white to
brownish-yellow spines. Stems
about 2.5 inches in diameter (6
cm).
Cold Tolerance: To low 20’s F
Watering Needs: Water
generously during the summer.
Heat Tolerance: Light shade in
Phoenix in summer
Blooming Habits:
Pinkish-red to orange-red tubular
diurnal flowers, 1.6 inches long (4
cm)
Sun Exposure: Full sun
Origin: Argentina to southern
Bolivia
Page | 3 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
CLEISTOCACTUS SEPIUM
Family: Cactaceae
Genus: Cleistocactus
Species: sepium
Synonym: Borzicactus
websterianus
Recommended Temperature
Zone:
USDA: 9b-10
Heat Tolerance: Light shade in
hot interior climates
Sun Exposure: Light shade to full
sun
At the Ruth Bancroft Garden we
have a form, received under the
name Borzicactus websterianus,
which is quite floriferous. It is a
little over 2 feet (60 cm) tall, with
a stem diameter of 3 inches (75
cm). Like other forms of
Cleistocactus sepium, this plant
has stems which normally do not
branch, but over time new ones
arise from the base to form a
clump.
South America has many kinds of
clump-forming cacti with slender
columnar stems, growing upright
initially, but often tending to
sprawl as they elongate. As with
so many groups of cacti, these
have gone through multiple name
changes as different authors have
come up with differing taxonomic
treatments. In recent years many
of them have been included in
the genus Cleistocactus. One of
these is a plant named
Cleistocactus sepium from the
Andes mountain range in
Ecuador.
Cleistocactus sepium has red
tubular flowers which flare out at
the mouth, making a brilliant
display. They jut out from the
sides of the stems below the
apex, coming in flushes during
the summer and fall months.
Flower length for the species is
given as 5-8 cm (about 2-3
inches); our plant at RBG has
flowers about 2½ inches long.
The round fruits start out green,
yellowing as they mature.
This species does well as a garden
subject in our area, needing only
occasional water during the
summer and good drainage.
Cleistocactus sepium is a variable
species, and different forms of it
were given separate names under
the genus Borzicactus in the
classification system of Curt
Backeberg.
It can be propagated from seeds
or cuttings.
Text and photos by Brian Kemble
Page | 4 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
CLEISTOCACTUS STRAUSII
Family: Cactaceae
Genus: Cleistocactus
Species: strausii
Common Name: Silver Torch
Cactus
Recommended Temperature
Zone:
USDA: 9-10
Frost Tolerance: Hardy to 14°F (10°C), but the tips might get
damaged below 23°F (-5°C)
Growth Habits: Clustered erect
cylindrical stems to 8 feet tall (2.4
cm) densely clad in bristly white
spines. Stems about 2.5 inches in
diameter (6 cm).
Watering Needs: Moderate
summer water
Propagation: Seeds or cuttings
Blooming Habits:
The silver torch starts blooming
when the columns are 18 inches
tall (45 cm). They bloom freely in
cultivation. The 3-inches long
flowers are deep burgundy, they
protrude horizontally from the
side of the columns near the tips.
Heat Tolerance: In hot interior
climates appreciates light shade
Sun Exposure: Full sun to light
shade
Origin: Bolivia, Argentina
CLEISTOCACTUS WINTERI
Family: Cactaceae
Genus: Cleistocactus
Species: winteri
Common Name: Golden Rat Tail
Synonym: Hildewintera
aureispina, Winterocereus
aureispinus
Recommended Temperature
Zone:
USDA: 9b-11
Frost Tolerance: To 28°F (-2°C)
Heat Tolerance: In hot interior
climates appreciates light shade
Sun Exposure: Light shade to full
sun
Origin: Argentina to Uruguay
Propagation: Seeds or cuttings.
Cultural Practices:
Good drainage and protection
from extreme lows. If it likes its
growing conditions you will also
be rewarded by the pink flowers
that come in abundance.
This cactus is sensitive to mealy
bugs that find a lot of hiding
ground among the spines.
Blooming Habits: The
Cleistocactus winteri has salmonpink flowers from spring through
autumn, 1.6 to 2.4 inches (4 to 6
cm) in length, 2 inches (5 cm) in
diameter. Mature plants bloom
repetitively. The flowers are
followed by green fruit, 0.4 inches
long (1 cm).
Growth Habits: Columnar cactus
forming masses of columns, up to
3 feet tall (90 cm), stems 2.5
inches in diameter (6 cm); 16 to
17 ribs; spines 50, 0.16 to 0.4 inch
long (0.4 to 1 cm)
Watering Needs: Regular water
in summer, keep rather dry in
winter
Page | 5 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
CYLINDROPUNTIA CALIFORNICA
Family: Cactaceae
Genus: Cylindropuntia
Species: californica
Common Name: Cholla
The word “Cholla” pronounced “
“Cho-ya” is the Mexican word
which applies to all of the
Cylindropuntias including this
one.
Synonym: Opuntia hamiltonii
Recommended Temperature
Zone:
USDA: 8a-9b
Sun Exposure: Full sun to partial
shade
Origin: Mexico (Northern Baja
California)
Growth Habits: Shrubby cactus,
up to 8 feet tall (2.4 m)
Watering Needs: Little water
Propagation: Cuttings
Blooming Habits:
Yellow flowers in early summer.
ECHINOCACTUS GRUSONII
Family: Cactaceae
Genus: Echinocactus
Species: grusonii
Common Name: Golden Barrel
Cactus
one of the 2 genera of cacti
commonly known as barrel cacti.
The other genus, with
considerably more species, is
Ferocactus. The two groups are
widely distributed in the
southwestern US and Mexico.
This is one of the most popular of
all cacti in cultivation. It is much
admired for its large rotund form,
dramatically adorned with neat
rows of clustered golden spines.
The flowers are also golden
yellow in color, emerging from
the large patch of wool at the
center of the plant. They are
produced a few at a time over a
long period during the growing
season in the warm months of
the year. Large plants attain a size
of over 2 feet across, and may
remain single or produce
plantlets at the side to form a
clump.
The Golden Barrel Cactus is one
of The Ruth Bancroft Garden’s
signature plants, and is a favorite
of volunteers and visitors. Each
September the Golden Barrel
Cactus Award for Philanthropy,
named for our prized plant, is
presented at the Annual Dinner In
The Garden benefit. This year the
founder of The Garden
Conservancy, Frank and Anne
Cabot, will receive the award.
Photo and text by Brian Kemble
They come from Queretaro State
in Mexico, but have become very
scarce in the wild
due to inundation of much of
their natural habitat from
construction of a dam.
Echinocactus, with 6 species, is
Page | 6 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
ECHINOCACTUS PLATYACANTHUS
Family: Cactaceae
Genus: Echinocactus
Species: platyacanthus
After this, they settle into their
solid-green mature appearance.
In some of the wild populations,
plants remain globular
throughout their lives, even when
they become huge specimens 4
feet tall (over a meter). In the
southern part of the species’
range, however, plants go on to
become stout-columnar and may
attain heights of 7 or 8 feet (2½
meters). The name E. grandis
was coined for this tall-growing
Form, but in other respects these
plants do not differ significantly
from other forms, so modern
taxonomists do not consider the
difference sufficient to warrant
even a separate variety.
In the early days of cactus
classification, the genus
Echinocactus was conceived of as
a very broad category taking in
many diverse globular cacti from
both North America and South
America. Now, however, the
name is restricted to 5 species
native to Mexico and the
southwestern U.S. These plants,
along with members of the genus
Ferocactus, are popularly known
as barrel cacti. Although there
are not many species of
Echinocactus, plants are
abundant in nature over a wide
area from the California deserts
in the north down to northern
Oaxaca.
The most widely-distributed of
all, and also the largest, is
Echinocactus platyacanthus. It
occurs from southern Coahuila
southward through the dry areas
of eastern Mexico to the OaxacaPuebla border area. Plants vary
somewhat through its range,
and different forms have been
given separate species names.
These are no longer recognized,
but nurseries, collectors and
gardens still often feature plants
labeled as E. ingens, E. palmeri,
and E. grandis, all of which are
now considered forms of E.
platyacanthus.
Echinocactus platyacanthus is not a fast-growing plant. After over 30 years in the
ground at RBG, our largest specimen is
about a foot and a half in height (½
meter), as compared to the giants found
in some parts of its range, which may be
over 2 meters in height.
This cactus has an unusual progression
from seedling to adult. When young,
plants are quite blue in color, followed by
a stage in which they become green with
striking red or purple stripes.
The spines on E. platyacanthus
are stout, but they are shorter
and less numerous than those of
their close relative E. grusonii (the
golden barrel cactus), so the plant
body is less obscured by them.
In both species, there is a large
pool of buff-colored wool
covering the central growing
point, and the flowers are
produced at the rim of this area.
Both species have bright yellow
flowers, but those of E.
platyacanthus are larger. Many
other kinds of cacti have a
particular time of year when they
produce a concentrated burst of
flowering, but E. platyacanthus
flowers on-and-off throughout
the summer (this is true of E.
grusonii as well).
Text and Photos by Brian Kemble
Page | 7 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
ECHINOCEREUS CINERASCENS
Family: Cactaceae
Genus: Echinocereus
Species: cinerascens
Common Name: Hedgehog
Cactus (applied to various species
in the genus)
Recommended Temperature
Zone:
USDA: 9-11
Frost Tolerance: Hardy at least to
25° F (-4°C)
Sun Exposure: Light shade to full
sun
Origin: Central Mexico
Watering Needs: Little water,
needs porous well drained soil.
Propagation: Branches freely
from the base
Blooming & Fruiting Habits:
Large pink to purple flowers in
abundance, up to 5 inches in
diameter (12 cm) with usually
with yellow or cream center,
stigma with 11 lobes. They come
from the side areoles and are
followed by edible greenish spiny
fruits tasting like strawberry.
Growth Habits: Clumping stems,
12 inches tall (30 cm), 2 (to 4)
inches in diameter (4-10 cm); 5 to
8 (to 12) blunt prominent ribs,
slightly warty; 1 to 4 (to 6) central
spines, 0.8 to 1.8 inches long (24.5 cm); 7-10 radials, 0.4 to 1.4
inches long (1-3.5 cm)
ECHINOCEREUS VIERECKII
Family: Cactaceae
Genus: Echinocereus
Species: viereckii
Growth Habits: Semi-prostrate
yellowish green stems branching
From the base to form a clump. In
the variety morricalii (pictured
here), the spines are absent,
showing off the wrinkly-skinned
chubby stems.
Sun Exposure: Full sun
Origin: Mexico (Nuevo Leon,
Tamaulipas)
Watering Needs: Little water,
needs porous well drained soil.
Blooming Habits:
Large magenta flower.
Page | 8 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
ECHINOPSIS BRUCHII
Family: Cactaceae
Genus: Echinopsis
Species: bruchii
colored flowers, or as giant
Lobivias. But now that all these
groups have been swept up into
Echinopsis, we don’t need to
worry about which side of the
fence to put them on.
Synonym: Soehrensia bruchii
This month’s plant profile
features Echinopsis bruchii and
also provides a lesson in plant
taxonomy. Echinopsis, as
currently defined, is a large genus
of cacti from South America
which range from tall, saguarolike columnar plants to small
globular ones. This expanded
concept of the genus takes in
several groups that were
previously classed as separate
genera, but there were always
problems in keeping them
separate because of plants that
straddled the border between the
groups. The 3 largest of these
groups are: 1) Echinopsis (in the
narrow sense) -- mostly globular
plants with long funnel-form
night-opening flowers, usually
white but sometimes pink or pale
yellow; 2) Lobivia – small globular
plants with short, day-opening
flowers, usually brightly-colored;
3) Trichocereus – tall columnar,
or short-columnar clumping,
plants with large flowers, typically
white and night-opening. On the
border between the Lobivias and
the Trichocerei is a smaller group
formerly known as Soehrensia.
They have a globular form and short
colorful day-opening flowers, but are
large compared to Lobivias. They might
be thought of a squat Trichocerei with
Echinopsis bruchii is the least
spiny and most clumping-prone
of the former Soehrensia group,
and it comes from northwestern
Argentina. The heads may range
in size from softball-sized to
cantaloupe-sized or even larger,
and the flowers are red or redorange. We have several
specimens of this plant at The
Garden, and they have performed
very well under our conditions.
Neither freezing spells in winter
nor hot spells in summer seem to
deter them. The plant pictured is
the largest-growing and heaviestflowering of the ones in our
collection, and also has the most
polished appearance. It produces
several flushes of red flowers in
April to June.
Text and Photos by Brian Kemble
Page | 9 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
ECHINOPSIS CANDICANS
Family: Cactaceae
Genus: Echinopsis
Species: candicans
Among the plants included in the
genus Echinopsis is a group which
used to be considered a separate
genus, Trichocereus. These have
large funnel-form flowers (usually
white) and columnar stems. In
some cases, like the San Pedro
cactus, the stems are tall and
erect. In other species, such as
Echinopsis candicans, the stems
initially grow upright, but sprawl
to the side as they lengthen. E.
candicans sprouts new stems
from the base, so eventually the
plant gives the appearance of a
cluster of stems radiating
outward from a central growing
point.
The large white flowers of Echinopsis
candicans emerge in May-June, often
coming in several successive flushes. The
buds, as with other species of Echinopsis,
are furry. As they emerge, they swell
into enormous trumpet-like blooms
about 6 inches across. Most other
species in the genus are unscented, but
these are an exception and perfume the
air with a
delightful fragrance.
The blossoms are short-lived, but
people visiting at the right time
are often amazed to see a
profusion of flowers which can
almost completely cover the
plant.
E. candicans comes from western
Argentina, which does not
experience the dry summers and
wet winters which characterize
California’s climate. However, it
thrives here if given a modest
amount of water during its
summer growing period. It can
endure temperatures down to
the low twenties Fahrenheit
without injury, and flowers
reliably each spring.
Text and photos by Brian Kemble.
ECHINOPSIS PACHANOI
Family: Cactaceae
Genus: Echinopsis
Species: pachanoi
Origin: Mountains of Ecuador and
Peru, between 5000 and 9000
feet elevation (1500m and
2700m)
Common Name: San Pedro
Cactus
Growth Habits: Multi-stemmed
columnar cactus, up to 20 feet tall
by 6 feet spread (6 by 1.8 m)
Recommended Temperature
Zone:
USDA: 8b-10
Watering Needs: Little water
when established
Frost Tolerance: Hardy to 15°F (10°C)
Propagation: Cuttings, seeds
The San Pedro Cactus stems
contain small quantities of
mescaline, a hallucinogenic drug.
Sun Exposure: Full sun to part
sun
Blooming Habits:
The San Pedro cactus is night
blooming, Its white flowers, in
July, are up to 9 inches in
diameter (22 cm)
Page | 10 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
ECHINOPSIS SPACHIANUS
Family: Cactaceae
Genus: Echinopsis
Species: spachianus
Growth Habits: Multi-stemmed
columnar cactus, basally
branching, 2 to 2.5 inches in
diameter (5-6 cm), 7 feet tall (2
m); 10 to 15 ribs; yellowish
areoles turning grey as they age;
1 to 3 yellowish centrals, 0.5 inch
long (12 mm); 8 to 10 radials, 0.5
inch long (12 mm).
Common Name: Golden Torch
Cereus
Recommended Temperature
Zone:
USDA: 9b-11
Watering Needs: Moderate water
Propagation: Cuttings
Frost Tolerance: Frost tender
Sun Exposure: Full sun
Blooming Habits:
Large white nocturnal flowers in
late spring. The flowers are up to
8 inches long (20 cm), 6 inches in
diameter (15 cm)
Origin: Western Argentina,
Bolivia
ECHINOPSIS TARIJENSIS
Family: Cactaceae
Genus: Echinopsis
Species: tarijensis
Growth Habits: Columnar cactus,
solitary at first, then branching
from the side, dark green stems,
up to 18 feet tall (5 m), 8 to 14
inches in diameter (20-35 cm);
about 15 ribs; large, close set
areoles with gray felt; 3 to 4
centrals, up to 3 inches long (7.5
cm); many radials, 20 or more, up
to 1.6 inches long (4 cm)
Synonym: Helianthocereus poco
Recommended Temperature
Zone:
USDA: 10-12
Hardiness: Hardy to the midtwenties F. or lower
Watering Needs: Little water,
needs good drainage
Sun Exposure: Outside full sun or
afternoon shade, inside needs
bright light, and some direct sun.
Blooming Habits:
Reddish purple diurnal flowers,
near the stem tips, in summer, 4
to 4.8 inches long (10-12 cm). The
fruit is ovoid, 1.4 to 2 inches long
(3.5-5 cm), 0.8 to 1.2 inches in
diameter (2-3 cm)
Origin: Argentina, Bolivia
Page | 11 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
ECHINOPSIS TERSCHECKII
Family: Cactaceae
Genus: Echinopsis
Species: terscheckii
Watering Needs: Little water,
needs good drainage
Propagation: Seeds
The Cardon Grande is probably
the largest Echinopsis. It is
occasionally used in landscaping
as a faster growing substitute to
the Saguaro. It has 8 to 14 ribs.
Areoles are about 1 inch apart
(2.5 cm). They have up to 15
strong, yellow, spines sometimes
over 3 inches long (7 cm),
generally less.
Synonym: Trichocereus
terscheckii
Recommended Temperature
Zone:
USDA: 8b-11
Frost Tolerance: Hardy to 18° F (8° C)
Sun Exposure: Full sun
Origin: Northern Argentina
Growth Habits: Columnar cactus
branching above ground, reaches
over 25 feet tall (7.5 m), branches
are around 10 inches in diameter
(25 cm); 8 to 14 ribs; large
brownish areoles, 1 inch apart
(2.5 cm); 8 to 15 yellowish spines,
3.2 to 4 inches long (8-10 cm).
Blooming Habits:
The flowers are white, nocturnal,
up to 8 inches long (20 cm).
ECHINOPSIS THELOGONA
Family: Cactaceae
Genus: Echinopsis
Species: thelogona
Growth Habits: Sprawling
columnar cactus, with the stems
normally staying upright for only
a short time before they begin to
spread horizontally along the
ground. New stems sprout from
the base from time to time.
Synonym: Trichocereus
thelogonus
Origin: Argentina
Recommended Temperature
Zone:
USDA: 9b-11
Watering Needs: Little water,
needs good drainage
Propagation: Cuttings, seeds
Frost Tolerance: Takes some
limited frost
Blooming Habits:
Echinopsis thelegona has white
nocturnal funnel-shaped flowers
in summer, about 8 inches long
(20 cm). The fruit is red, hairy,
about 2 inches long (5 cm) When
ripe, it splits on one side,
revealing black seeds.
Heat Tolerance: Afternoon shade
in very hot climate
Sun Exposure: Full sun
Page | 12 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
ESPOSTOA LANATA
Family: Cactaceae
Genus: Espostoa
Species: lanata
Growth Habits: Clump-forming
columnar cactus, slow-growing
but eventually up to 10 ft tall (3
m).
Common Name: Peruvian Old
Man Cactus
Watering Needs: Rot prone in
winter, keep it dry
Recommended Temperature
Zone:
USDA: 9b-11
Origin: Southern Ecuador,
northern Peru
Propagation: Seeds
The name of the genus, Espostoa,
comes from the Peruvian botanist
Nicholas Esposto.
Frost Tolerance: tolerates down
to 25°F (-3°C) for short periods,
but frost should still be avoided.
Blooming Habits:
The Peruvian Old Man Cactus has
nocturnal flowers, 2 inches in
diameter, white to purple in late
spring, early summer.
Sun Exposure: Full sun to light
shade
FEROCACTUS ECHIDNE
Family: Cactaceae
Genus: Ferocactus
Species: echidne
Growth Habits: Barrel cactus,
globose when young, but
eventually becoming shortcolumnar. Though armed with
sharp spines, these are not as
dense as many other barrel cacti,
so the plant body is readily
visible.
Origin: Eastern Mexico
Recommended Temperature
Zone:
USDA: 9b-11
Frost Tolerance: Will take some
frost
Blooming Habits:
Diurnal yellow flowers, 0.8 to 1.8
inches long (2-4.5 cm), 1.2 to 1.4
inches in diameter (3-3.5 cm), in
late spring.
Sun Exposure: Full sun
Origin: Central Mexico
Page | 13 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
FEROCACTUS GLAUCESCENS
Family: Cactaceae
Genus: Ferocactus
Species: glaucescens
Growth Habits: A modest-size
barrel cactus with a globose stem
under 2 ft. tall and yellow spines.
May be solitary or form a clump.
Recommended Temperature
Zone:
USDA: 9b-11
Propagation:
Ferocactus glaucescens is a
magnificent species with glaucous
grey body and golden spines.
Frost Tolerance: Will take some
frost
Blooming Habits:
Yellow flowers, 1.2 to 1.5 inches
in diameter (3-4 cm), in summer.
White fruit, 0.8 inch long (2 cm).
Sun Exposure: Part sun to full sun
Origin: Eastern central Mexico
(Hidalgo)
.
FEROCACTUS HISTRIX
Family: Cactaceae
Genus: Ferocactus
Species: histrix
Growth Habits: A round-bodied
barrel cactus to 4 ft. tall.
Somewhat resembles the Golden
Barrel cactus, but the spines are
less dense and have a pale-yellow
color, rather than golden yellow.
Common Name: Electrode Cactus
Recommended Temperature
Zone:
USDA: 9b-12
Watering Needs: Little to no
water when established
Frost Tolerance: Will take some
frost
Blooming Habits: Pale yellow
flowers in April – June.
Sun Exposure: Full sun
Origin: Central Mexico
Page | 14 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
FEROCACTUS LATISPINUS
Family: Cactaceae
Genus: Ferocactus
Species: latispinus
The other central spines are still
stout, but much narrower and not
curved. The smaller radial spines
surround these. The plants are
most often wider than they are
tall.
Members of the genus Ferocactus
are commonly called barrel cacti,
and they occur in the
southwestern United States and
in the drier areas of Mexico. One
species with an extensive
distribution in central and
southern Mexico is Ferocactus
latispinus, which normally
remains a solitary plant, without
dividing or producing offsets.
Ferocactus latispinus is modestsized for a barrel cactus, and all of
the plants at the Ruth Bancroft
Garden are under a foot in
diameter, though they may attain
a size of up to 16 inches. In the
cactus family the spines radiate
out from nubs called areoles, and
the spines are divided into central
spines (usually stouter and at the
center of the areole) and radial
spines (usually finer and at the outside).
F. latispinus has several central spines,
but one is conspicuous since it is very
wide and flat and hooked or curved at
the end. This prominent spine is usually
red, but may be yellow.
Most species of Ferocactus flower
in spring or summer, but our
plants of F. latispinus at RBG
consistently bloom in the fall,
usually in October. It might be
noted that this is not true of the
closely related F. latispinus ssp.
spiralis (syn. F. recurvus); our
specimen of this plant flowers in
summer and is taller-growing.
Our F. latispinus plants have richpurple flowers about an inch and
a half across, providing a
welcome burst of color at a time
of year when not many cacti are
in bloom.
Text and Photos by Brian Kemble
FEROCACTUS PILOSUS
Family: Cactaceae
Genus: Ferocactus
Species: pilosus
Origin: NE Mexico
Growth Habits: Clumping barrel
cactus (sometimes remains
single), up to 8 ft tall (2.4 cm).
This is an attractive shortcolumnar plant with intermeshed
stout red spines as well as wispy
hair-like spines. It flowers in
spring and though its flowers do
not open widely, they are notable
for their vivid orange color. It is
drought tolerant, but needs
occasional summer water, since
this is its growing season.
Common Name: Mexican Fire
Barrel Cactus
Recommended Temperature
Zone:
USDA: 9b-11
Frost Tolerance: Hardy to 25°F (4°C)
Propagation: Seeds
Sun Exposure: Full sun
Page | 15 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
FEROCACTUS POTTSI
Family: Cactaceae
Genus: Ferocactus
Species: pottsi
Growth Habits: This roundbodied cactus gets to be about 3
ft. tall usually remaining solitary.
It has prominent ribs, with
clusters of spines at intervals
along them. Because the spines
are short, the chubby smooth
green plant body is on full display.
The large yellow flowers come in
summer, and are followed by
long-lasting attractive yellow
fruits. Needs occasional watering
in summer.
Recommended Temperature
Zone:
USDA: 9b-11
Sun Exposure: Full sun
Origin: Mexico (Chihuahua,
Sinaloa, Sonora), in deciduous
vegetation, from 800 to 3300 feet
elevation (240 to 1000 m)
Named for John Potts, manager
of a mine in Ciudad Chihuahua.
FEROCACTUS ROBUSTUS
Family: Cactaceae
Genus: Ferocactus
Species: robustus
Growth Habits: One of the
smallest-headed barrel cacti, but
it forms many-headed mounding
clumps in time (ancient
specimens in Mexico are up to 10
ft. across). The heads on our
plants do not exceed 5 in. across,
though they can get somewhat
larger than this. This species can
be distinguished from the similarlooking F. flavovirens by the
number of ribs: 8 for F. robustus
vs. 11-13 for F flavovirens .
Ferocactus rubustus has 1.5 in.
yellow flowers at intervals during
the fall months. It needs little
water once established.
Origin: South central Mexico
(Puebla)
Recommended Temperature
Zone:
USDA: 9-12
Frost Tolerance: Hardy to 20°F (6°C)
Sun Exposure: Full sun
Propagation: Seeds, offsets
Page | 16 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
GYMNOCALYCIUM SAGLIONIS
Family: Cactaceae
Genus: Gymnocalycium
Species: saglionis
Growth Habits: This species is a
giant among the gymnocalyciums,
or chin cacti, reaching a foot in
diameter. The body is divided into
chubby, rounded tubercles with
creases between them with about
12-15 spreading pinkish-gray
spines sprouting from the areoles
atop each one. The white to
pinkish-white flowers emerge
near the top in successive flushes
during summer. It needs
occasional watering in summer,
and is propagated from seeds
since it does not make offsets.
Common Name: Giant Chin
Cactus
Recommended Temperature
Zone:
USDA: 9b-11
Frost Tolerance: 20°F (-7°C)
Sun Exposure: Full sun
Origin: Argentina
.
HARRISIA POMANENSIS
Family: Cactaceae
Genus: Harrisia
Species: pomanensis
Growth Habits: A clump-forming
scrambling cactus with stems up
to 2 in. or so in diameter. The
stems are initially erect, but then
arch to the side unless supported
by surrounding vegetation. The
spine length is variable. The large
nocturnal white flowers bloom at
RBG in late summer, but start
earlier in warmer climates. The
vivid red fruits which follow in
autumn are round or oval in
shape, with pointed red bract
leaves at intervals, but no spines.
The fruits look similar to those of
Hylocereus undatus, also called
Dragon Fruit, but Hylocereus
fruits have larger and longer
bracts which are usually greentipped.
Origin: Argentina, Bolivia,
Paraguay
Common Name: Applecactus,
Dragon Fruit
Recommended Temperature
Zone:
USDA: 10-12
Frost Tolerance: Avoid frost
Sun Exposure: Full sun to light
shade
Page | 17 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
HYLOCEREUS UNDATUS
Family: Cactaceae
Genus: Hylocereus
Species: undatus
Growth Habits: A clamboring
cactus which can climb up trees
or spread laterally, rooting as it
goes. The stems are 3-sided, with
wavy margins and clusters of very
short spines at intervals. It is an
aggressive grower, and will root
readily from cuttings, but is has a
very limited tolerance for cold
and is easily damaged by freezes.
Its huge nocturnal flowers come
in summer to early fall. They are
white with a little yellow on the
narrower outermost petals. The
red edible fruits which follow are
similar to those of Harrisia
pomanensis, but with larger
bracts. Our plant in the Winter
House at RBG lacks suitable
pollinators and does not set fruit.
Origin: Widely cultivated, origin
uncertain, probably West Indies
and Caribbean basin
Common Name: Night-blooming
Cactus, Dragon Fruit
Recommended Temperature
Zone:
USDA: 10-11
Heat Tolerance: Avoid frost
Sun Exposure: Full sun to
afternoon shade
Watering Needs: Regular water
MAMMILLARIA HAAGEANA
Family: Cactaceae
Genus: Mammillaria
Species: haageana
Synonym: Mammillaria dealbata
Growth Habits: There are many
species of mammillarias, most of
them from Mexico, though a few
occur in the SW United States.
These plants are very popular
with collectors and are often seen
as potted plants. Mammillaria
haageana is one of the whitespined species, with spiraling
rows of fine white spines covering
the plant. It is normally singleheaded, but sometimes offsets to
make a clump. The heads are up
to 4 in. across, and produce a ring
of small magenta or deep pink
flowers in late winter to spring.
Good drainage is essential.
Recommended Temperature
Zone:
USDA: 9b-11
Frost Tolerance: Hardy to at least
25°F (-4°C)
Sun Exposure: Light shade
Propagation: Seeds
Page | 18 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
MAMMILLARIA GEMINISPINA
Family: Cactaceae
Genus: Mammillaria
Species: geminispina
Growth Habits: Mammillaria
geminispina is a clumping species,
forming large mounds of 3 to 4 in.
heads in time. It has needle-like
white spines, as well as white
wool between the tubercles. It
produces small deep pink to
lavender-pink flowers in fall and
early winter, and these are
scattered here and there rather
than arranged in a tight ring as
with M. haageana. It should be
protected from too much cold
and wetness in winter, and can be
propagated from seed, or by
removing heads.
Recommended Temperature
Zone:
USDA: 10
Frost Tolerance: Hardy to 28°F (2°C)
Sun Exposure: Full sun
Origin: Central Mexico (Hidalgo
state)
Watering Needs: Regular water
in summer
Propagation: Seeds, the best
clones are propagated by offset.
The Mammillaria geminispina
clumps readily and make large
mounds in the wild. The sap of
the Mammillaria geminispina is
milky.
NEOBUXBAUMIA POLYLOPHA
Family: Cactaceae
Genus: Neobuxbaumia
Species: polylopha
Growth Habits: Solitary columnar
cactus, up to 40 feet tall (12 m),
with many narrow ribs and fine
yellowish spines. It has occasional
bouts of flowering in summer,
first forming stubby cylindrical
buds which are green at the base
and dark red at the tips. When
the flowers open, the petals
curve outward to display the pink
flower face and the cluster of
creamy anthers.
Recommended Temperature
Zone:
USDA: 9b-11
Frost Tolerance: Takes some frost
Origin: Mexico (Guanajuato,
Hidalgo, Querétaro, San Luis
Potosí)
Page | 19 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
OPUNTIA BASILARIS
Family: Cactaceae
Genus: Opuntia
Species: basilaris
Common Name: Beavertail
Cactus
Recommended Temperature
Zone:
USDA: 7-10
Frost Tolerance: Hardy to 0°F (18°C)
Sun Exposure: Full sun
Origin: Southwest USA (Arizona,
California, Nevada) from 200 to
3000 feet elevation (60 to 900 m),
northwestern Mexico (northern
Baja California and northern
Sonora)
Growth Habits: Succulent to 2
feet tall (60 cm), 4 feet spread
(1.2 m); green or slighly purplish
segments 3.2 to 5.6 inches long
(8-14 cm), 1.6 to 4 inches wide (410 cm), glabrous or slightly
pubescent; slightly pleated during
the dry season; areoles, many
with white or brown wool and
brownish Glochids; occasional
spine in the upper areoles, or
spineless.
Watering Needs: little or no
water once established, in its
natural distribution area, it
receives mostly winter rains.
Propagation: Cuttings
The Beaver-tail Cactus is a smaller
prickly pear cactus, and it will
often start blooming when it has
only two pads. Beware that the
glochids (these little barbed
bristles organized in clusters) can
penetrate the skin.
In the wild, its principal range is
limited to the Mojave-Colorado
desert.
Blooming Habits:
The beaver tail cactus has 2.6-3
inches wide (6-7 cm), fuschia
colored flowers in March-April.
The spineless fruit is dry when
ripe. The seeds are 0.24 to 0.4
inch in diameter (6-10 mm)
OPUNTIA ENGELMANNII
Family: Cactaceae
Genus: Opuntia
Species: engelmannii
Growth Habits: A shrubby prickly
pear which can grow to 6 or 7 ft.
tall, but is usually less. It has
rounded to oval green pads with
spines up to 2 in. long, and yellow
flowers in spring. These are
followed in fall with many red
edible fruits. Easy to grow and
needs very little water.
Origin: Arizona, California (USA)
Common Name: Engelmann's
Prickly pear, Calico Cactus
Recommended Temperature
Zone:
USDA: 9-10
Sun Exposure: Full sun
Page | 20 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
OPUNTIA FICUS-INDICA
Family: Cactaceae
Genus: Opuntia
Species: ficus-indica
Common Name: Prickly Pear
Growth Habits: A trunk-forming
prickly pear to 15 ft. tall, with
green pads which may be oval or
paddle-shaped. It has few spines,
but glochids can still cause
trouble, so the pads should be
handled with care. This is the
most commonly cultivated prickly
pear, grown both for its edible
young pads (nopales) and for its
tasty fruit (tunas). It has yellow or
orange flowers in spring, and
showy fruit in the fall, which may
be orange, red or purplish-red.
Severed pads root and grow
readily.
Origin: Mexico
Hardiness: to mid 20s; damaged
in low 20s
Size: to 15ft, spread to 10ft
Exposure: full or reflected sun
Water: natural rainfall; pads
shrivel in times of drought
indicating need for supplemental
water
OPUNTIA LEUCOTRICHA
Family: Cactaceae
Genus: Opuntia
Species: leucotricha
Growth Habits: Tree-like prickly
pear, up to 16 feet tall (5 m). The
oval pads have fine white spines,
which cover the trunk as well
(leucotricha means “white hairs”).
Its light yellow to greenish-yellow
flowers open in June and July at
RGB, and they are followed by
round fruits 1½ in. across. Though
initially green, the fruits turn pale
yellow at maturity in the fall.
Needs little water.
Recommended Temperature
Zone:
USDA: 9b-11 (to 25°F/-3.8°C)
Origin: Mountains of central
Mexico
Sun Exposure: Full sun to partial
shade
Danger: Plant has spines or sharp
edges; use extreme caution when
handling
Page | 21 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
OPUNTIA ROBUSTA
Family: Cactaceae
Genus: Opuntia
Species: robusta
Growth Habits: A large growing
prickly pear which may develop a
trunk, but could also grow more
like a large shrub. It is notable for
its large round or oval bluish
pads. It has bright yellow flowers
in spring, and an abundance of
large, juicy reddish-purple fruits
in fall. Drought tolerant.
Common Name: Silver Dollar
Prickly Pear, Dinner Plate Cactus
Recommended Temperature
Zone:
USDA: 9-11
Sun Exposure: Full sun
Origin: Central Mexico
OPUNTIA TOMENTOSA
Family: Cactaceae
Genus: Opuntia
Species: tomentosa
Growth Habits: A large prickly
pear with a trunk. The oval pads
are modest in size and with very
short spines, but they are unusual
in being pubescent (with a
coating of “peach-fuzz”). The
flowers are red-orange, with the
main burst of flowering in June,
but a few flowers continuing
through summer. The abundant
red fruits are present all through
the fall.
Common Name: Wooly Joint
Prickly Pear, Velvet Opuntia,
Velvet Tree Pear
Sun Exposure: Full sun
Origin: Mexico, Guatemala
Height: 6 – 15 feet (1.8 – 4.7 m)
Hardiness: USDA: 8b-10b (to
15°F/-9.4°C)
Page | 22 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
OREOCEREUS CELSIANUS
Family: Cactaceae
Genus: Oreocereus
Species: celsianus
Common Name: Old Man of the
Andes
Growth Habits: Columnar cactus
which can grow to a height of
over 10 ft. (3 m); our largest
specimen in the garden is nearly
12 ft. tall, with a stem diameter of
8 in., but plants are normally less
than this. It normally branches
from the base to make a cluster
of columns, but plants also
occasionally branch higher up.
The stems are covered with long
wispy white hairs, with stout
spines protruding from this. The
tubular 3 in. to 3½ in. flowers are
pink at their flared tips, and
emerge in May and June. This
plant needs little water and good
drainage, and is winter-hardy in
our area.
Recommended Temperature
Zone:
USDA: 8-10
Frost Tolerance: Hardy to 10°F (12°C)
Sun Exposure: Full sun
Origin: Bolivia, Peru, northern
Argentina
Propagation: Seeds
OREOCEREUS DOELZIANUS
Family: Cactaceae
Genus: Oreocereus
Species: doelzianus
Growth Habits: This Oreocereus
is much smaller than O. celsianus,
forming large clumps of stems
which do not exceed 3 ft. in
height. The stems start out erect,
but tend to splay to the side as
they get older. Its wool is not as
thick or long as its larger cousin,
and the spines are not as stout.
However, it has a much longer
blooming season, with beautiful
magenta-pink flowers. Needs no
frost protection in our climate
zone.
Recommended Temperature
Zone:
USDA: 9-11
Origin: Andes of central Peru
Sun Exposure: Light shade to full
sun
Watering Needs: Let the soil dry
between watering
Propagation: Seeds, cuttings
Page | 23 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
PARODIA HORSTII
Family: Cactaceae
Genus: Parodia
Species: horstii
Synonyms: All plants formerly
placed in the genus Notocactus
have now been moved into
Parodia
Origin: Brazil (Rio Grande do Sul)
Recommended Temperature
Zone:
USDA: 9b-11
Frost Tolerance: Hardy to 25°F (4°C)
Sun Exposure: Light shade to full
sun
Parodia is a South American
genus of cacti, occurring in
southern Brazil, Uruguay,
Paraguay and Argentina.
Typically they are globose,
though some elongate into short
cylinders over time. The flowers
emerge near the apex of the
plant, and are often very showy.
Yellow is the most common
flower color, though some
species have flowers in other
colors (orange, pink, red or
green).
Growth Habits: This modest-size
globular cactus is one of many
Parodia species native to
southern Brazil. It may be solitary,
or may produce offsets to form a
small cluster. Plants grow to be 6
to 8 in. in diameter (15 to 21 cm),
with a height of up to 1 ft. (30
cm). The spines are bristly rather
than stout and stiff, and there is a
pool of wool at the center
concealing the growing point. The
flowers, which are up to an inch
across or a little more (13 cm)
emerge from this wool in flushes
all year long. The flower color
ranges from yellow-orange to
magenta.
Watering Needs: Regular water in
summer. Keep rather dry in
winter, rot easily if the substrate
is wet and cold, tends to lose its
roots in winter.
Propagation: Seeds
PARODIA LENINGHAUSII
Family: Cactaceae
Genus: Parodia
Species: leninghausii
Common Name: Golden Ball
Cactus
Synonyms: Notocactus
leninghausii, Eriocactus
leninghausii
Recommended Temperature
Zone:
USDA: 9b-11
Growth Habits: This clustering
species has short-cylindrical
stems to 2 ft. or more high (60
cm) and 4 in. in diameter (10 cm),
densely clad in fine bristly goldenyellow spines. Its satiny lightyellow flowers open widely to
about 2 in. across (5 cm), with
flowering coming at intervals
from summer to early fall. This
plant is easy to grow if given
periodic water in summer, and it
can be propagated by removing
offsets or by growing it from
seed.
Frost Tolerance: 25°F (-4°C), or
possibly colder
Sun Exposure: Light shade to full
sun
Origin: Southern Brazil (Rio Grand
do Sul)
Page | 24 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
PARODIA MAGNIFICA
Family: Cactaceae
Genus: Parodia
Species: magnifica
Growth Habits: A clustering
spherical-bodied green or bluegreen cactus with sharply-defined
ribs, each with a fringe of fine
bristly spines running down its
length. The stem diameter
reaches 5 to 6 in. (12.5 to 15 cm)
on mature heads. It flowers in
flushes during the summer and
early fall, with clusters of light
yellow flowers to nearly 2 in.
across (5 cm). Needs occasional
water in summer, and can be
grown from seed or by separating
the offsets.
Synonyms: Notocactus
magnificus, Eriocactus magnificus
Recommended Temperature
Zone:
USDA: 9a-11
Frost Tolerance: 20°F (-7°C)
Sun Exposure: Light shade to full
sun
Origin: Brazil
PARODIA WARASII
Family: Cactaceae
Genus: Parodia
Species: warasii
The large, pale-yellow flowers
appear in summer, opening at the
Ruth Bancroft Garden in July and
August.
Parodia warasii is a solitarygrowing species from the state of
Rio Grande do Sul in southern
Brazil.
This species, like other members
of the genus, is a summer
grower. Plants should be
watered periodically through the
warm season. P. warasii prefers
filtered light or half-day sun,
rather than being exposed to the
full brunt of the sun all day. It has
been growing at the garden for
many years, though its position
with tree branches overhead
gives it some protection from
cold spells.
Young specimens are spherical,
but eventually they grow into a
cylinder up to 2 feet tall.
Plants have 15 or more ribs
running vertically down the plant
body, with deep grooves between
them. The ribs are lined with
closely-spaced areoles, each with
a cluster of bristly brownishyellow spines.
Plant Highlight by Brian Kemble
Page | 25 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
STENOCACTUS OCHOTERENANUS
Family: Cactaceae
Genus: Stenocactus
Species: ochoterenanus
Synonym: Echinofossulocactus
ochoterenanus
Common Name: Brain Cactus
Recommended Temperature
Zone:
USDA: 9b-11
Frost Tolerance: Hardy to 25°F
(-4°C)
Sun Exposure: Some direct sun
Origin: Mexico (Hidalgo,
Queretaro, Guanajuato)
Growth Habits: A modest-size
clobular cactus which may
remain single-headed or offset
to form a clump. The stem
diameter is up to 4 in. (10 cm).
This plant has many narrow wavy
ribs, but these are often obscured
by densely interwoven spines,
with a few longer and stouter
spines (up to 2½ in. long or 6.5
cm) protruding outward. The
newest spines may be more
intensely colored, varying from
dark brown to yellow, but older
spines are pale (straw-colored or
whitish). The flowers emerge
early, from late March to April,
and range in color from white,
with a purplish-red stripe down
the middle of the petal, to pink or
purplish-pink.
TEPHROCACTUS ARTICULATUS
Family: Cactaceae
Genus: Tephrocactus
Species: articulates
Common Name: Paper Spine
Cactus
commonly grown of these is
Tephrocactus articulates. Like the
other species, it is a shortgrowing clumper with stems in
distinct segments, and these may
be rounded or elongated. The
color of the plants is variable
depending on the clone and the
growing conditions, ranging from
green to gray-green to purplishgray to brownish. The stems can
be up to an inch or more in
diameter (2½ to 5 cm) and
become wrinkled under dry
conditions. A common form of
the species has very prominent
wide white papery spines; this is
often seen under the name T.
articulates var. papyracanthus.
However, other forms are lacking
the spines altogether. The stem
segments are easily dislodged,
and rooting them is the usual way
of propagating the species.
Origin: Western Argentina
Recommended Temperature
Zone:
USDA: 8b-10
Sun Exposure: Full sun
Watering Needs: little or no
water once established
Growth Habits: Plants in the
genus Tephrocactus are
relatives of the Opuntias which
come from Argentina, where
they can be found quite far
south, in areas which get
winter freezes, and also in cold
high altitude zones. However,
they do not really like wet
winters, so good drainage is
essential for growing them out
in the garden. Many names
have been assigned to various
groups, but modern taxonomy
treats most of these as
synonyms, recognizing only a
handful of species. The most
When they can be persuaded to
flower, these plants have
attractive white or pinkish-white
flowers up to an inch and a half
across (3½ to 4 cm).
Page | 26 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
THELOCACTUS CONOTHELOS
Family: Cactaceae
Genus: Thelocactus
Species: conothelos
Recommended Temperature
Zone:
USDA: 8b-11
The longer protruding central
spines are surrounded by many
smaller spreading radial spines.
While the density of the spines
varies, they are usually not so
dense as to obscure the plant
body. The showy flowers, which
emerge in spring, are about 1⅓ to
1½ inches across (3½ to 4 cm).
The usual flower color is
magenta, though yellow-flowered
and white-flowered plants may
also be encountered.
Origin: Northeast Mexico
Growth Habits: A globular
cactus, usually single, with a
stem diameter of 3 to 6 inches
or more (7½ to 17 cm). The
green body is composed to
many tubercles which are not
arranged in ribs, each topped
with a cluster of light grayishbrown or whitish spines.
This plant likes plenty of sun, and
because it seldom makes offsets
it is usually grown from seed. Like
the other members of its genus, it
comes from a summer-rainfall
area, and needs very good
drainage if grown outdoors in
regions with winter rainfall.
THELOCACTUS RINCONENSIS
Family: Cactaceae
Genus: Thelocactus
Species: rinconensis
Origin: Northeast Mexico
The plant body is completely
covered with large tubercles, with
a cluster of a few spines atop
each. The largest of the spines
can be quite heavy and long,
usually starting out dark, but soon
graying and often becoming
shredded at the margins as it
ages.
Growth Habits: This is the
largest-growing species in the
genus, with a diameter of up to
nearly 8 inches (20 cm). It is
normally single, and wider than
it is tall. Its color varies from
ash-gray to blue-gray to bluegreen.
This species likes a sunny position
with good drainage, and it is
spring-blooming. The flowers are
about 1½ inches across (4 cm),
and white to yellowish-white in
color, sometimes with a pink or
purplish-pink mid-stripe. Seed is
the usual method of propagation.
Recommended Temperature
Zone:
USDA: 9-11
Page | 27 Docent Training 2011 - 2012
Plant Profiles - Cactaceae
THELOCACTUS TULENSIS
Family: Cactaceae
Genus: Thelocactus
Species: tulensis
has varieties with wider stems (up
to nearly 6 inches across, or 15
cm) which are solitary. The basic
body color is green, but plants in
bright light may become reddish
or tinged with purple.
Recommended Temperature
Zone:
USDA: 9b-11
The flower color in T. tulensis is
quite variable, ranging from white
to yellow to pink or magenta. The
flower diameter is 1⅓ to 1¾
inches (3½ to 4½ cm), though
those of the var. matudae may be
larger. As with the other species
of Thelocactus, this one comes
from a summer-rainfall area, and
extra-good drainage is called for if
it is grown outside in the winterrainfall zone. Propagation is from
seed or offsets.
Origin: Northeast Mexico
Growth Habits: This species
has a rounded to somewhat
elongated body, covered with
rounded to rounded-pyramidal
tubercles topped with slender
spines. In older plants, one
spine is typically especially long
(up to 3 inches, or 8 cm). The
typical form frequently
clusters, and has a stem
diameter of 2⅓ to 3 inches or a
little more (6 to 8 cm), but it
Page | 28 Docent Training 2011 - 2012