2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013

Questions and Answers: 2020

Question: I have a Pagoda dogwood tree in my backyard. My question is about the scientific name; is it Swida alternifolia …

• Question

  I have a Pagoda dogwood tree in my backyard. My question is about the scientific name; is it Swida alternifolia or Cornus alternifolia? I keep hearing that the DNA studies do not hold up for Swida. Please enlighten me.

  Answer

  Dear Plantperson, DNA studies contribute to our understanding that Swida is a distinct lineage from the other dogwoods. You are hearing they do not uphold because many botanists (amateur and professional) consider the recognition of four genera of dogwoods unpopular. However, Swida is distinctive in its morphology, phylogeny, geography, patterns of hybridization, and physiology (freeze tolerance is correlated with the four genera). There is ample evidence to recognize the four genera (including Swida). DNA sequence studies using phylogenetic methods demonstrate four distinctive lineages--but those data alone do not necessitate changes, they only support change from our typical way of treating this genus. Best wishes.