Within Mammillaria karwinskiana, four subspecies have been recognized, which include the subspecies: Mammillaria karwinskiana subsp. beiselii, Mammillaria karwinskiana subsp. collinsii, Mammillaria karwinskiana subsp. karwinskiana, and Mammillaria karwinskiana subsp. nejapensis.
Scientific Name
Mammillaria karwinskiana Mart.
Common Name(s)
Royal Cross, Royal Cross Cactus
Synonym(s)
Cactus karwinskianus, Mammillaria karwinskiana subsp. karwinskiana, Neomammillaria karwinskiana
Scientific Classification
Family: Cactaceae
Subfamily: Cactoideae
Tribe: Cacteae
Subtribe: Cactinae
Genus: Mammillaria
Etymology
The specific epithet "karwinskiana (kar-winz-kee-AH-na)" honors Wilhelm Friedrich Karwinsky von Karwin (1780-1855), a Bavarian naturalist who collected plants and animals in Brazil (1821-1826) and Mexico (1826-1831, 1840).
Origin
Mammillaria karwinskiana is native to Guatemala and Mexico (Chiapas, Oaxaca, Puebla, Morelos, Guerrero, Michoacán, and Colima). It grows in tropical deciduous forests and xerophilous scrub at elevations between 490 and 6,890 feet (150 and 2,100 m).
Description
Mammillaria karwinskiana is a small cactus with green, spherical to short cylindrical stems with pyramidal, spirally arranged tubercles tipped with clusters of spines. The stems can grow solitary or slowly branch basally or dichotomously, reaching up to 8 inches (20 cm) in height and 4.8 inches (12 cm) in diameter. They develop white tomentum at the apex. The axils of the tubercles have tufts of white hair and long white bristles. Each areole usually bears six straight to slightly curved radial spines. The spines are cream to reddish with a brown tip, become chalky white with age, and grow up to 1.2 inches (3 cm) long. The central spines are absent.
The flowers are funnel-shaped, cream to medium yellow with purplish midveins, and appear in spring, forming a circle around the stem just below the apex. They can reach up to 1 inch (2.5 cm) in length and 0.6 inches (1.5 cm) in diameter. The fruits are red, club-shaped, and quite attractive.
How to Grow and Care for Mammillaria karwinskiana
Light: For optimal growth of your Mammillaria karwinskiana, ensure it is planted in an area that receives at least four hours of direct sunlight daily. If growing indoors, placing the cactus near a bright window is best to ensure it gets enough light. For additional light, it is advisable to keep it on the balcony or in the garden from spring to fall.
Soil: To ensure good root aeration and drainage, use commercial cactus soil or create your own well-draining soil mix.
Temperature: Mammillaria karwinskiana is heat tolerant but is not a cold-hardy plant. It grows best in USDA Plant Hardiness Zones 9b to 11b, with average minimum winter temperatures ranging from 25 to 50 °F (-3.9 to 10 °C).
Watering: Water deeply from spring to fall, and wait until the soil dries out before watering again. Never let your pot sit in water, and suspend watering when the plant goes dormant in the winter.
Fertilizing: During the growing season, Mammillaria karwinskiana benefits from fertilization. Apply a water-soluble fertilizer for cacti and other succulents. Suspend feeding during the winter when the plant goes dormant.
Repotting: Repot the cactus into a slightly larger pot every two or three years, preferably during late winter or early spring. However, repotting can be done at any time of the year.
Propagation: There are two easy ways to propagate Mammillaria karwinskiana: by seeds or by dividing offsets. The best time to remove offsets is in spring and summer. Sow the seeds in late spring or summer for the best results.
Learn more at How to Grow and Care for Mammillaria.
Toxicity of Mammillaria karwinskiana
Mammillaria karwinskiana is non-toxic but has sharp spines, so keep it away from children and pets.
Subspecies of Mammillaria karwinskiana
Links
- Back to genus Mammillaria
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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