The popular houseplant genus Calathea is frequently grouped with the “Prayer Plant,” a nickname that is botanically inaccurate. The true Prayer Plant belongs to the genus Maranta. Both genera are closely related and display a remarkable trait of moving their leaves in response to the light-dark cycle. This shared characteristic, combined with their similar tropical origins, leads to the common mislabeling and interchangeable use of the term.
Defining the “Prayer Plant” Family
Both Calathea and Maranta are members of the same botanical family, Marantaceae, which explains their visual similarities and shared leaf movement trait. The Marantaceae family, often referred to as the arrowroot family, is a group of tropical plants native to the rainforests of Central and South America. This common ancestry means they thrive in similar environments, preferring shaded, humid conditions.
The species most accurately called the Prayer Plant is Maranta leuconeura, known for its striking red-veined foliage and highly noticeable leaf movement. Because of this distinct species, the entire Maranta genus earned the common name. Many Calathea species also exhibit the movement, leading to the generalization of the “Prayer Plant” nickname across both genera.
Botanically, the distinction lies at the genus level, a subdivision of the family. The Calathea genus contains numerous species, while Maranta remains a separate, smaller genus. Despite these scientific classifications, the shared common name persists due to the similar visual effect and care requirements. This confusion highlights how common names often prioritize observable traits over strict biological taxonomy.
The Science Behind the Movement
The phenomenon that gives these plants their nickname is nyctinasty, a biological process linked to the plant’s internal circadian rhythm in response to light changes. During the day, the leaves of both Calathea and Maranta lie flat to maximize the surface area for absorbing sunlight. As darkness approaches, the leaves fold or stand upright, resembling hands folded in prayer.
The mechanism responsible for this visible movement is a specialized, swollen joint located at the base of the leaf stalk, known as the pulvinus. The pulvinus contains motor cells that rapidly change size by altering their internal water pressure, known as turgor pressure. At night, water moves out of the cells on the underside of the pulvinus, causing the joint to relax and the leaf to fold upward.
Conversely, during the day, water flows back into the underside cells, increasing the turgor pressure and forcing the leaf to return to its horizontal position. This movement is theorized to help the plants conserve moisture, protect the foliage from cold evening temperatures, or allow excess water to drain off the leaf surface. Maranta generally exhibits a more dramatic and easily observed movement than many Calathea varieties.
Practical Differences Between Maranta and Calathea
The most immediate difference between the two genera is their growth habit. Maranta species, such as M. leuconeura, typically have a low-growing, spreading, or creeping habit, making them excellent choices for hanging baskets. In contrast, most Calathea species possess a more upright, shrub-like form, with stiff stems that hold the leaves vertically, and can reach heights up to one meter.
Visually, Maranta leaves are often oval-shaped with distinct, painted patterns, such as red veins on the underside of the leaf. Calathea offers a much wider variety of leaf shapes, sizes, textures, and colors, including pleated, velvety, or lance-shaped foliage. This diversity makes Calathea the larger and more varied genus in terms of ornamental appeal.
In terms of care, Maranta is generally considered a more forgiving houseplant compared to Calathea. Both prefer high humidity and consistently moist soil. Calathea varieties are sensitive to environmental stress and can react quickly to low humidity or mineral-heavy tap water by developing brown leaf edges or curling its leaves. Maranta tends to tolerate slight fluctuations in home environments with fewer immediate signs of distress.