Sky blue aster

Sky blue aster (Aster oolentangiensis) is now in full bloom. This attractive but delicate plant is found primarily in dry to dry-mesic prairies.

When we first started restoration, this species was present in small amounts on our steep south-facing slope. Kathie collected seed which we used in planting Toby's Prairie, which was the first prairie we planted. Now in its 15 growing season, Toby's Prairie is our driest planted prairie, and has a nice, diverse flora.

We have seen sky blue aster in this prairie since about 2002, but mostly in scattered areas. This year, probably because of the good weather, it is all over, frequently in large patches. Right now is a good time to see it.

Sky blue aster in Toby's Prairie

It is easy to tell sky blue aster from smooth aster (Aster laevis), another dry prairie species. The latter has clasping leaves up the stem, whereas sky blue has only basal leaves with long petioles.

Most botanists know sky blue aster by the Latin name azureus, which is more descriptive. However, the rules of botanical nomenclature are strict, and the name first validly described in the literature is the one that must be used. There were two early publications describing this species, one by John L. Riddell published in April 1835, the other by Lindley in November 1835. Unfortunately, Riddell's publication came first.

Riddell was one of the first botanists to visit the Midwestern states, and he described this plant from forests along the Oolentangy River near Worthington, Ohio. Thus, the species name "oolentangiensis".

For details of this naming situation, the paper by Almut Jones, published in 1983 in the Bulletin of the Torrey Botanical Club (Vol. 110, pp. 39-42), should be sought. Recognizing the consternation that his paper would elicit, Jones begins his paper: "With a certain amount of regret, I am introducing evidence which will necessitate the replacement of the well-established names of two eastern North American species with names that have priority under the Rules of Nomenclature..."

Many Wisconsin plant ecologists have resisted this name change, although it is the preferred name in the Wisconsin State Herbarium. However, as an Ohio native who received his botanical training at Ohio State University, I have had no trouble with this new species name. The Oolentangy River flows through the Ohio State campus, and the first plant ecology field trip I ever attended dealt with the flora of this river.

One final point: the "oo" spelling is not  used for the river any more. Google etc. will try to force you to use a  single "o". To do a search for the "oo" spelling, put Oolentangy in quotes.

However, the correct spelling of the aster species epithet is with the "oo" and will be accepted by Google without quotes.