Plant names change over time

Remembering the names of plants can be challenging, and recalling their scientific names adds an extra layer of complexity. Common names for plants vary widely, making it even more challenging to consistently identify a particular species. Take the bleeding heart, for instance, which goes by alternative names such as lyre flower, heart flower, and lady-in-a-bath. The introduction of scientific names was intended to provide a standardized way of referring to species, facilitating universal communication among individuals regardless of their geographical location. These names were designed to aid in grouping plants based on shared characteristics, aiming to enhance clarity and precision in botanical discussions. have been far more numerous over the years.

This fluidity in nomenclature underscores the dynamic nature of botanical science and highlights the ongoing efforts to capture the complexity of the plant kingdom with precision and fidelity. Plant names uphold the principle that names must represent true evolutionary relationships. So as we learn more about a species and its relationships, names must be modified to follow.

Plants that have had gone through name changes:

• Bleeding Heart formerly known as Dicentra spectabilis is now Lamprocapnos spectabilis
• Tomato formerly in the genus Lycopersicon; now it’s a Solanum
• Blue wood aster formerly known as Aster cordifolius is now Symphyotrichum cordifolium
• Russian sage formerly known as Perovskia atripicifolia is now Salvia yangii
• Joe-pye weed formerly known as Eupatorium spp. is now Eutrochium spp. 

It's hard enough to remember what a plant is called, much less remember the scientific name. We expect to hear different common names for plants.For example alternate names for bleeding heart are lyre flower, heart flower and lady-in-a-bath. Scientific names were supposed to make it easier to know that two people, from anywhere, are talking about the same exact species. It was supposed to help group plants by familiar characteristics. 

Why do plant names change? The answer is research. As scientists learn more about a plant they may find information that it was an incorrect identity, two species may have been combined into one group, or an old naming scheme that just didn't fit. 

It makes life difficult if all you want to do is buy a plant like you saw in a neighbors' yard. An article in the Pacific Horticulture Society by Matt Ritter gives examples of the many name changes of Douglas-fir. "Douglas-fir has changed scientific names nearly twenty times since its discovery by Europeans, from Pinus taxifolia, through Abies douglasii, eventually settling on Pseudotsuga menziesii, where it remains today." 

The importance in scientific naming is important when a name is mentioned in a large room of experts everyone in that room is picturing the same exact species. Granted, few people will need to worry about what name was used in the 1800s. When it all began, plants were named and grouped by similar visible features like reproductive parts or leaves. Today plant taxonomy is being redefined by DNA testing. Botanists and taxonomists are learning more about the evolutionary relationships of plants. This will likely lead to many more changes in the future. In the meantime, we will need to continue to have those familiar "do I know you?" conversations.

References: 

• "Why do plant names change?" by Christopher Whitehouse, RHS Herbarium at Wisley, 
• International Plant Name Index (IPNI)
• Integrated Taxonomic Information System (ITIS)
• World Flora Online