Echinocactus grusonii f. cristatus

Echinocactus grusonii f. cristatus

Family: Cactaceae
Common Name: crested golden barrel cactus, crested mother-in-law’s cushion, crested golden ball cactus
Origin: The traditional Echinocactus grusonii is native to central Mexico, being found in the Rio Moctezuma Valley (5). In the wild Echinocactus grusonii is found on rocky volcanic slopes, and while it is abundant in cultivation, it is endangered in habitat (9,10,11). The construction of a dam has made the traditional golden barrel cactus critically endangered in its native habitat, with as few as 50 remaining in the wild (13). The genus name “echinocactus” is a combination of the Greek word “echinos” meaning “hedgehog”, and “cactus”, with the specific epithet “grusonii” being honored after the German engineer Hermann Jacques Gruson (1821-1895) (9,11,12). Gruson had a special interest in desert plants and built the famous Gruson Greenhouses where he amassed the largest collection of cacti in Europe (12).

Description: Echinocactus grusonii f. cristatus is a rare, crested form of the traditional Echinocactus grusonii, which is a large globular barrel cactus (1,6). This crested form has an irregular shape, having a wavy cristate growth formation (1,2,6,8). The stem is a pale green coloration and grows to heights of 6-18 inches (1,2,5,6,7). This plants stem is heavily ribbed, with very densely packed golden spines (1,4,6,7). The spines are long and sharp, and they can be straight or have a slight curvature (7). The bright yellow spines are radially positioned on numerous areolas (1,5,6,7,9). The flowers are diurnal and yellow in coloration, roughly 1-3 inches wide, and are somewhat inconspicuous given their small size in relation to the stem, as well as being concealed by dense spine coverage and apex wool (1,3,5,6,7). The fruits are globular in shape with a greenish coloration, containing many tiny brown seeds (9). This plant can produce offsets at maturity (2,5).

Interesting Features:
- The flowers are diurnal, opening in the day and closing at night (1,5,6,7).
- The Echinocactus grusonii f. ‘cristata’ is a rare, crested forma of the traditional golden barrel cactus (1,6,8).
Uses: The crested golden barrel cactus’s sole ethnobotanical use is as an ornamental, being prized for its rarity (1,8). The crested golden barrel cactus is beloved for its vibrant gold spines just as the traditional species, but its wavy cristate form makes it an exceedingly striking accent piece in any greenhouse (1,2,6,8). Given its incredibly sharp spines and toxicity, it is recommended that it is kept away from children and pets (1,2,4,6)

Cultivation and Care:

Watering: Low
- This plant is drought tolerant (2,3).
- This plant is very sensitive to excessive moisture and will perish if overwatered, a soak-and-dry watering method is recommended (4,5,9).
- The crested golden barrel cactus goes into winter dormancy, and during this rest period the plant needs almost complete dryness (1,4,5,6,9).
- Watering can resume in March, by gradually increasing frequency until May when its growth period begins (1,4,5,6).
- Routine watering is recommended for the rest of the summer while allowing the soil to dry out between applications, however in extreme heat more frequent watering may be necessary. (1,4,5,6).
- Begin to scale back watering again in late September to prepare for the dry winter-period (1,5,6)
- Refrain from watering directly onto the body of the cactus to prevent fungal infections, as well as prevent burning when in direct sunlight (5).
Soil: This plant should be repotted every other year to provide fresh soil medium, and it is recommended to cease watering following repotting for at least a week (5).
- This plant will not tolerate waterlogged soil and requires a well-draining potting medium to prevent root-rot (4,5).
- Fertilizing is unnecessary if it has been re-potted recently, if not, a high-potassium fertilizer can be applied during the summer growing period, but do not fertilize during its winter dormancy period (1,5,6).
Lighting: Full sun
- This plant thrives in full-sun and will tolerate light shade (1,2,3,4,6,7,9). Full sun is optimal, and in oppressive shade the plant may become vulnerable to rot and overwatering, as well as adopt a lusher green coloration (1,6,9).
- When kept in inadequate sunlight, the spines may lose their golden luster (1,6).
Propagation: The crested golden barrel cactus is best propagated by cuttings or pups (1,2,5,6).
- For cutting propagation, allow the cut to callous over before inserting into potting medium (2).
Cold Tolerance: Tender, USDA hardiness zones 9b to 11b.
- This plant is not cold-hardy and in zones below 9b it should be grown in pots and brought inside during the winter (2,3,4).
Special Accommodations:
- The crested golden barrel cactus is relatively fast growing in its younger years, however, it slows down considerably as it ages (4).
- This plant flowers in late-spring and summer, however only large mature specimens that receive full sun will flower (1,3,4,5,6,7).
- This plant is toxic and heavily spined, so care should be taken when handling, as well as keeping it of reach from children and pets (1,2,4,6)

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