Stomatium species, often called “living stones” or “tooth plants,” are distinctive succulents from South Africa. They thrive in arid conditions, and their unique appearance makes them appealing to succulent enthusiasts.
What Are Stomatium Species?
Stomatium is a genus of approximately 40 succulent species in the Aizoaceae family (ice plants). These low-growing plants form dense, clumping mats. Their fleshy, often grayish-green leaves can develop purplish tints in intense sunlight. A key feature is their textured leaves, which have tiny bumps and small, pointed, whitish “teeth” along their margins, creating a jaw-like appearance. This “open mouth” look is where their name “Stomatium” (from the Greek “stoma”) originates.
Native to the arid, rocky regions of South Africa, these plants blend into their environment. Many species produce fragrant, daisy-like yellow or white flowers on short stalks. A notable trait is their nocturnal or late-afternoon blooming; flowers open as the sun sets and close by morning. This adaptation attracts pollinators active during cooler parts of the day.
Cultivating Stomatium Species
Stomatium species thrive when their environmental needs, mimicking arid habitats, are met. Providing proper conditions ensures robust growth and minimizes common issues, contributing to their overall health.
Light Requirements
Stomatium species require bright, direct sunlight, ideally at least six hours daily. While they tolerate some partial shade, especially in summer, insufficient light causes etiolation. This stretching makes plants leggy and less compact.
Watering Practices
Stomatium succulents are drought-tolerant and sensitive to overwatering. Use the “soak and dry” method: water thoroughly until it drains, then let the soil dry completely. During their active growing season (fall and winter), water moderately. Reduce watering significantly during summer dormancy (above 86°F/30°C) to prevent rot.
Soil and Drainage
Stomatium species require extremely well-draining, gritty soil. A commercial succulent or cactus mix amended with 50% to 70% mineral grit (e.g., perlite, pumice, coarse sand) is recommended. This ensures adequate drainage and aeration, preventing waterlogging and root rot.
Temperature and Airflow
Stomatium species tolerate warm temperatures, and good air circulation helps prevent fungal problems. They are not cold-hardy and are sensitive to frost; temperatures below 41°F (5°C) can cause damage. For optimal growth, maintain temperatures above 50°F (10°C). In cold winter regions, bring outdoor plants indoors to a frost-free environment.
Fertilization
Stomatium species generally require minimal fertilization. If repotted every two years into fresh soil, additional feeding may not be necessary. To encourage faster growth, apply a diluted, low-nitrogen fertilizer once a month during the active growing season. Avoid fertilization entirely during dormancy, as excess nutrients can harm the plant.
Common Problems and Solutions
Even with proper care, Stomatium species can encounter issues. Recognizing signs and implementing timely solutions helps maintain their health and appearance, preventing problems from escalating.
Etiolation
Etiolation, or stretching, indicates insufficient light. Stomatium plants become leggy with elongated stems and widely spaced leaves. Stretched growth will not revert to a compact form, but moving the plant to a brighter location (e.g., a south-facing window or grow light) encourages new, healthy growth. Beheading the stretched portion and propagating the healthy top can restore the plant’s aesthetic.
Rot
Root and stem rot are frequent problems, almost always caused by overwatering or inadequate drainage. Symptoms include mushy, discolored tissue at the plant’s base or in the roots. If detected, immediately unpot and inspect the roots. Cut away any affected, soft sections with a sterile knife. Allow remaining healthy parts to dry and callous for several days before repotting into dry, well-draining soil.
Shriveled Leaves
Shriveled or wrinkled leaves often indicate underwatering, especially during the active growth period. While drought-tolerant, prolonged lack of water causes leaves to lose turgidity. A thorough watering typically rehydrates them within days. Distinguish this from the natural reabsorption of older, lower leaves, which is a normal process.
Pest Issues
Stomatium species are relatively pest-resistant, but common succulent pests like mealybugs and spider mites can appear. Mealybugs show as white, cottony masses in leaf crevices; spider mites cause fine webbing and tiny brown dots. Regular inspection helps detect infestations early. Treatment often involves dabbing pests with rubbing alcohol or using insecticidal soap.