Both *Pachira aquatica* and *Pachira glabra* belong to the Malvaceae family, specifically the subfamily Bombacoideae. They are closely related but distinct species within the same genus. Their common names often cause significant confusion. *Pachira aquatica* is widely known as the "Money Tree" in horticulture, a name that is frequently and incorrectly applied to *Pachira glabra* as well. *Pachira aquatica* is also called the Malabar chestnut or Guiana chestnut. *Pachira glabra*, on the other hand, is more accurately referred to as the Saba nut or French peanut. This misapplication of the "Money Tree" name is the primary source of confusion between the two plants.
The structure and texture of the trunk are among the most reliable diagnostic features for distinguishing these two species. *Pachira aquatica* typically develops a noticeably swollen or bulbous trunk base, especially when grown in conditions that mimic its natural wetland habitat. Its bark is a smooth, greenish-brown color. In contrast, *Pachira glabra* has a more consistent, non-swollen trunk that does not develop the same pronounced basal swelling. Its bark is consistently smooth and maintains a distinctive grey-green to olive-green hue, which is a key identifying trait.
The flowers of these two species are structurally different upon close inspection. Both produce large, showy flowers with long, creamy-white to pale yellow stamens. However, a key difference lies in their petals and overall presentation. The flowers of *Pachira aquatica* have long, narrow petals that curl backwards, typically in a reddish-brown or greenish color, and they are often tinged with yellow. The flowers of *Pachira glabra* are generally more uniform and lack the strong curling of the petals; their petal color is usually a more consistent cream or white. Furthermore, *Pachira aquatica* is generally self-incompatible, often requiring cross-pollination, while *Pachira glabra* is self-fertile and can readily set fruit with its own pollen.
The fruits provide another clear point of differentiation. *Pachira aquatica* produces a large, oblong, woody capsule that can grow up to 12 inches (30 cm) long. This fruit has a rough, brown exterior and dehisces (splits open) along five seams when ripe to reveal its large, edible seeds. The seeds of *P. aquatica* are irregularly shaped with a knobby surface. Conversely, *Pachira glabra* produces a smaller, smoother, olive-green fruit that is more elliptical in shape. Its fruit rarely splits open as dramatically and contains smaller, more regularly shaped seeds with a smoother testa.
While both species feature palmate compound leaves with 5 to 9 leaflets (glabrous), there are subtle differences. *Pachira aquatica* leaflets are often slightly larger and broader. In terms of growth habit, *P. aquatica* is a larger tree in its natural setting, capable of reaching over 60 feet (18 meters) in height, and it is semi-deciduous. *Pachira glabra* is generally a smaller, more compact, and fully evergreen tree, making it a slightly more manageable and popular choice for long-term indoor cultivation as a houseplant.
