Giant Larkspur, Rocket Larkspur, Larkspur
Consolida ajacis (L.) Schur
Consolida ambigua (L.) P.W. Ball & Heywood
Delphinium ajacis L.
The Plant List says Consolida ajacis (L.) Schur is the correct and accepted scientific name for the Giant Larkspur. It was described as such by Philipp Johann Ferdinand Schur in Verhandlungen und Mittheilungen des Siebenbürgischen Vereins für Naturwissenschaften zu Hermannstadt in 1853. It was first described as Delphinium ajacis by Carl von Linnaeus in Species Plantarum in 1753.
Some websites still use the species name Consolida ambigua. It was described as such by Peter William Ball and Vernon Hilton Heywood in Feddes Repertorium Specierum Novarum Regni Vegetabilis (Berlin) in 1962.
Since I found out that The Plant List is no longer maintained, I am cross-referencing scientific names with the new website from Kew called Plants of the World Online… When I checked Consolida ajacis it said it was a synonym of Delphinium ajacis. When I searched Consolida ambigua it said “no results found”. Many organizations, botanists, horticulturalists, etc. organized to make the Plant List including Kew and the Missouri Botanical Gardens (Tropicos). Tropicos is maintained by the Missouri Botanical Garden. Anyway, the 2017 updated version of Tropicos and The Missouri Botanical Garden still maintain Consolida ajacis is the accepted name. Plants of the World Online is still uploading data, so maybe at some point they will agree.
I finished my page on Delphinium and had to vent a little. I am STILL not ready to change the name here to Delphinium ajacis, although it was originally that name. As I pointed out on the Delphinium page, typically Consolida are annuals and their flowers are open and loosely branched. Delphinium flowers are more or less in a column. When I bought my Delphinium plants, the tag just said “Delphinium Mix’. Now I know why they looked like my Consolida ajacis… They are the same plant!!! Click HERE for the Delphinium page.
I think the seeds came from an Ebay seller Suzanne bought seeds from in 2009. The name on the package just said “Larkspur”. They came up every year in various places from seed and I never knew where they would come up. Sometimes I relocated them and other times I just mowed around them. There were blue, purple, white and pink flowers.
They are considered an annual, but readily self-seed which means they come up where you really don’t want them sometimes. They are easy to recognize by their ferny foliage. Just dig them up when they come up in the spring and put them where you want them. Even though were self-sowing, not very many came up each spring. They are considered a cool weather annual and in the south, they do fizzle out when it gets hot. Since they are an annual, I am not sure why information on the internet says they are hardy in USDA zones 2-11.
I must admit, I like the Larkspur and they make great additions to butterfly and hummingbird gardens. Just a great plant for any kind of cottage garden in general. I have to get some seed so I can plant them here on the farm someday.
If you have any comments, questions or suggestions, I would like to hear from you.