The popular houseplant known as the Wandering Jew, or Inchplant, belongs to the genus Tradescantia. Its slightly fleshy appearance often leads people to incorrectly classify it alongside cacti and other desert plants. Misclassification can lead to inappropriate care and plant failure. This article clarifies the botanical status of Tradescantia and explains the differences between its needs and those of a true succulent.
Defining Succulence and the Tradescantia Classification
Tradescantia is generally not classified as a true succulent, although some species are described as semi-succulent. Succulence is a specialized botanical trait defined by the presence of thickened, fleshy tissues adapted for storing large volumes of water, a survival mechanism for prolonged periods of drought. True succulents, such as Aloe or Echeveria, possess extensive water-storing cells, often composing 90–95% of the plant’s tissue volume, allowing them to function temporarily independent of an external water supply.
The genus Tradescantia is part of the Commelinaceae family, commonly known as the spiderwort family, which includes about 85 species of herbaceous perennials. While common species like Tradescantia zebrina or Tradescantia pallida exhibit some fleshiness, they do not meet the full criteria for succulence. Their water storage capacity is far less developed than that of a genuine desert-adapted plant.
Botanically, Tradescantia favors moist, well-draining conditions, unlike the arid environments where most true succulents thrive. The ability of some species to survive short dry spells is a trait of resilience, not a full adaptation to desert life. This slight drought tolerance is why the term “semi-succulent” is sometimes used, reflecting a partial adaptation in the stems and leaves.
Anatomical Features That Cause Misidentification
The primary reason Tradescantia is often mistaken for a succulent is its physical appearance, which shares visual characteristics with water-storing plants. Its stems are thick and the leaves are plump, giving the plant a fleshy, engorged look. This morphology suggests an ability to hold moisture, but it is misleading in terms of deep water reserves.
The plant’s leaves contain a mucilaginous, sticky sap, which contributes to the fleshy feel, but this is not the same as the specialized water-storage tissue found in a cactus. The slight fleshiness allows the plant to endure brief periods of dryness, but it lacks the comprehensive water-saving adaptations of desert species.
Many true succulents employ Crassulacean Acid Metabolism (CAM) photosynthesis, which minimizes water loss by opening stomata only at night to absorb carbon dioxide. Tradescantia plants do not utilize this specialized metabolism. This difference means Tradescantia will quickly transpire and lose water through its leaf surface if not regularly replenished, unlike a CAM plant.
Practical Care Differences for Non-Succulent Tradescantia
The non-succulent classification of Tradescantia has significant practical implications for its care, particularly concerning watering. True succulents require deep, infrequent watering, only after their soil is completely dry, which can mean weeks or even a month between drinks. Overwatering is the most common cause of death for these plants because their specialized tissues cannot handle prolonged wetness.
Tradescantia, in contrast, prefers a consistently moist, but not waterlogged, environment, aligning with its herbaceous origins. Watering is needed when the top inch or two of soil feels dry to the touch, resulting in a much more frequent schedule than a true succulent. Allowing the soil to completely dry out for an extended period will cause the leaves to brown and the plant to suffer, confirming it is not adapted for extreme drought.
The preferred soil type further highlights the difference. Genuine succulents require an extremely gritty, fast-draining mix to prevent water from sitting around the roots. Tradescantia thrives in a richer, well-draining potting soil that retains some moisture between waterings. Furthermore, Tradescantia benefits from higher humidity and occasional misting, a requirement that would be detrimental to most true succulents.