The change from Mina lobata to Ipomoea lobata is fundamentally a story of botanical taxonomy adhering to its own strict rules. The governing body for plant names is the International Code of Nomenclature for algae, fungi, and plants (ICN). A cornerstone principle of the ICN is priority. This means that the first validly published and legitimate name for a plant takes precedence over any later names. In this case, the genus name Ipomoea was published earlier than the genus name Mina. When botanists determined through detailed study that the plant known as Mina lobata was, in fact, more correctly classified within the larger Ipomoea genus, the rule of priority demanded that the older name, Ipomoea, be used.
The plant in question, a striking vine known for its cascading racemes of flowers that change color from red to orange to pale yellow, was first described by the Spanish botanist Antonio José Cavanilles in 1795. He placed it in the genus Ipomoea, naming it Ipomoea lobata. Later, in 1850, another botanist, José Jerónimo Triana, decided this plant was distinct enough from other morning glories to warrant its own genus. He created the new genus Mina for it, resulting in the well-known name Mina lobata. For many years, this name was widely accepted and used in horticulture. However, taxonomic understanding is not static; it evolves with new evidence.
The decisive shift back to the original name came with the advent of modern molecular phylogenetics. This scientific approach uses DNA sequencing data to reconstruct the evolutionary relationships between organisms. By comparing specific gene sequences of Mina lobata with those of numerous other species in the bindweed family (Convolvulaceae), researchers made a crucial discovery. The DNA evidence clearly showed that Mina lobata was not an isolated evolutionary branch deserving of its own genus. Instead, it was nested deep within the Ipomoea family tree, meaning its closest relatives were other morning glories. From a genetic and evolutionary perspective, it was simply another species of Ipomoea.
While DNA provided the definitive proof, this reclassification is also supported by morphological (physical form) characteristics. Although the flower shape of Ipomoea lobata is unusual for a morning glory—being tubular and borne on one-sided racemes rather than the typical wide, solitary trumpet—other key botanical features align it with Ipomoea. These shared traits include the structure of the seed capsule, the arrangement of leaves, and the overall growth habit as a twining vine. The unique inflorescence was deemed an adaptation within the genus, not a reason for generic separation. When viewed as a whole suite of characters, the plant fits comfortably within the broader morphological definition of Ipomoea.
This name change illustrates the dynamic nature of botanical science and can cause confusion in the gardening world. The name Mina lobata remains prevalent on seed packets and in nurseries due to its long-standing horticultural use. However, in scientific and increasingly in official horticultural contexts, Ipomoea lobata is the correct name. The reclassification also enriches our understanding of the Ipomoea genus, highlighting its remarkable diversity, which encompasses not only the classic blue morning glory but also species with highly specialized flowers like the firecracker vine. The correct name ensures that its true evolutionary relationships are reflected in its classification.
