Plant ID
GD-CAC-002-0019
Common Name(s)
- Arenaceous Crown Cactus
- Crown Cactus
Plant Photograph
📷 Figure 1. Rebutia arenacea Cárdenas
Photography: Green Desert Botanical Library
Plant Description
Rebutia arenacea Cárdenas is a small, compact cactus characterized by its rounded to slightly flattened green body, numerous spirally arranged tubercles, and short, pale spines arranged closely along the surface. When mature, the plant may produce offsets and develop into a small cluster.
Its most spectacular feature is its flowering habit. Numerous bright yellow to orange-yellow flowers emerge around the lower portion of the stem, often appearing in quantity during the flowering season. The contrast between the subdued, finely spined cactus body and its brilliant flowers gives the plant exceptional ornamental value.
The species was described by Bolivian botanist Martín Cárdenas in 1951 as Rebutia arenacea. It has subsequently been treated under the genera Sulcorebutia and Weingartia. Current Kew taxonomy places it in Weingartia, while Rebutia arenacea remains an important and widely recognized horticultural name.
Basic Information
Scientific Name: Rebutia arenacea Cárdenas
Current Accepted Name: Weingartia arenacea (Cárdenas) F.H.Brandt
Author Citation: Cárdenas
Family: Cactaceae
Genus: Rebutia
Current Taxonomic Placement: Weingartia
Historical Synonym: Sulcorebutia arenacea (Cárdenas) F.Ritter
Plant Type: Small globose to slightly flattened cactus
Origin: Central Bolivia
Plant Overview
Rebutia arenacea is a small highland cactus admired for its compact form, orderly spination, and exceptional flowering display. Young plants are generally solitary, while mature specimens may produce offsets and form small clusters.
The cactus has a distinctive geometric appearance created by numerous tubercles arranged in spiral rows. Fine pale spines radiate from the areoles in a comb-like arrangement, giving the plant a soft, finely textured appearance.
During the flowering season, numerous deep-yellow to orange flowers emerge around the base of the stem. The flowers can surround the plant like a colorful crown, making an otherwise small cactus highly conspicuous when in bloom.
Botanical Description
Growth Habit
A small, compact, globose to slightly flattened cactus.
Young plants are generally solitary but may produce offsets as they mature and eventually form small clusters.
Mature Size
- Stem height: approximately 2–4 cm
- Stem diameter: approximately 2–6 cm
- Overall cultivated height: up to approximately 10 cm
Growth is generally slow, and mature specimens remain relatively small.
Stem
- Globose to slightly flattened
- Green to brownish-green
- Compact and symmetrical
- Covered with numerous distinct tubercles
- Approximately 30 spiral rows of tubercles
Leaves
None.
As with other true cacti, the leaves have been evolutionarily modified into spines.
Spines
- Short and fine
- Pale white, cream, yellowish or occasionally brownish
- Approximately 14–16 radial spines per areole
- Closely arranged in a comb-like pattern
- Relatively short and close to the body
The neat arrangement of the spines is one of the plant’s principal identifying characteristics.
Roots
A fibrous root system adapted to rapidly draining, seasonally dry soils.
The roots are sensitive to prolonged waterlogging and require a porous growing medium.
Flowers
- Produced around the lower portion of the stem
- Usually numerous
- Deep yellow to golden yellow
- May develop orange-yellow tones
- Produced mainly during the flowering season
- Form a crown-like display around the plant
The flowers are the most prominent ornamental feature of the species.
Fruits
Small fruits develop following successful pollination.
Seeds
Produces small seeds within the mature fruits.
Seed propagation is possible and is useful for producing genetically variable plants.
Native Habitat
Geographic Distribution
Central Bolivia, particularly the dry inter-Andean regions of Bolivia.
The species is associated with the Cochabamba region and has a relatively restricted natural distribution.
Natural Ecosystem
- Seasonally dry inter-Andean valleys
- Dry shrubland
- Rocky habitats
- Semi-arid landscapes
Climate
A seasonally dry highland climate characterized by:
- Strong sunlight
- Distinct dry periods
- Seasonal rainfall
- Cooler conditions than lowland tropical environments
- Significant day-to-night temperature differences
Soil Type
Well-drained, porous, rocky or sandy soils with limited water retention.
Growing Conditions
Light
Thrives in bright light to full sun.
Strong light helps maintain compact growth, healthy spination and flowering.
In hot tropical climates, gradual acclimatization and some protection from extreme midday heat may be beneficial.
Watering
Water thoroughly during active growth and allow the growing medium to dry before watering again.
Avoid keeping the soil continuously wet.
During cool or dormant periods, watering should be reduced substantially.
Soil
Use a very porous and rapidly draining cactus mix containing a high proportion of mineral material.
Suitable components include:
- Pumice
- Lava rock
- Coarse sand or grit
- Perlite
- Other porous mineral materials
Only a limited amount of organic material is necessary.
Temperature
Ideal:
15–30°C during active growth
The plant benefits from a cooler, drier resting period.
Protect from prolonged exposure to excessive heat combined with high humidity and poor air circulation.
Humidity
Prefers relatively dry conditions with excellent air circulation.
In humid tropical environments, ventilation and very fast drainage are especially important.
Fertilization
Feed lightly during the active growing season with a diluted fertilizer formulated for cacti and succulents.
Avoid excessive nitrogen.
Potting
Use a small container with excellent drainage.
A shallow pot is generally suitable because of the plant’s compact growth habit.
Do not use an excessively large container that retains moisture around the roots for extended periods.
Propagation
Usually propagated from:
- Seeds
- Offsets
Seeds should be sown in a clean, porous growing medium under suitable warm and humid germination conditions.
Offsets can be separated from mature plants and allowed to dry before being placed in a well-draining medium.
Growth Rate
Slow.
A mature specimen may require several years to reach its full cultivated size.
Dormancy
Growth generally slows during cool or dry periods.
A pronounced dry resting period is beneficial and may encourage flowering in the following growing season.
Toxicity
⚠ Generally considered non-toxic
Rebutia arenacea does not produce the irritating milky latex characteristic of Euphorbia.
However, the plant has numerous spines that can cause:
- Skin punctures
- Irritation
- Minor wounds
Handle carefully when repotting or propagating.
Pests and Diseases
Common problems may include:
- Mealybugs
- Scale insects
- Spider mites
- Root rot caused by excessive moisture
- Fungal problems associated with poor ventilation and prolonged wet conditions
The greatest cultivation risk is generally overwatering and poor drainage.
Interesting Facts
- Rebutia arenacea was described by the Bolivian botanist Martín Cárdenas in 1951.
- The species has been classified under Rebutia, Sulcorebutia, and Weingartia at different times.
- Kew currently places the species under Weingartia arenacea.
- Its tubercles form numerous spiral rows around the stem.
- Its short spines are arranged in a distinctive comb-like pattern.
- Flowers emerge around the lower portion of the stem rather than only from the apex.
- Its bright yellow to orange flowers can create a spectacular crown-like display.
- The species remains very small even when mature.
- It is native to the dry highlands of Bolivia.
Landscape and Collection Value
Ideal for:
- Cactus collections
- Botanical gardens
- Rock gardens
- Xeriscape displays
- Container cultivation
- Greenhouse collections
- Specialty succulent displays
Its small size makes it suitable for limited spaces, while its spectacular flowering habit gives it exceptional display value.
The combination of compact geometry, delicate spination and brilliant flowers makes it particularly attractive as a specimen plant in the Green Desert collection.
Conservation Status
The species has a relatively restricted natural distribution in Bolivia. Available horticultural sources describe it as naturally scarce, making the conservation of cultivated specimens valuable for education and appreciation.
The exact current conservation status should be confirmed against the latest authoritative conservation assessment before assigning a formal IUCN category.
Cultivated specimens such as this one contribute to ex-situ conservation by maintaining living representatives of Bolivia’s distinctive cactus flora.
Life’s Whisper
“Even the smallest life can create a crown of beauty. Growth may be slow and quiet, but when the season is right, everything prepared in silence can burst into bloom.”
Green Desert Botanical Library Notes
This specimen forms part of the living collection of Green Desert Agritourism Park.
It is documented in the Green Desert Botanical Library as Rebutia arenacea Cárdenas, the name traditionally associated with this plant in horticultural collections.
Modern taxonomic treatment places the species under Weingartia arenacea (Cárdenas) F.H.Brandt, while Sulcorebutia arenacea is another historical combination. The Green Desert Botanical Library retains Rebutia arenacea as the primary display name to preserve continuity with the specimen’s established identification while also documenting its current taxonomic placement.
The specimen photographed at Green Desert displays the characteristic compact body, fine pale spination, and abundant yellow-orange flowers associated with this species.
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References
For the complete list of botanical references, scientific literature, and online resources used in preparing the Green Desert Botanical Library, please visit the References page available from the Main Menu.