A Case for Specifying Species and Ecoregion

A Case for Specifying Species and Ecoregion when Ordering Plants for a Restoration Project

With the advent of low-cost gene sequencing, botanists and plant taxonomists have been avidly collapsing several formerly recognized species into one and splitting off familiar species into new genus.  A few of the more disruptive changes include a) moving dozens of species from the Aster genus into the Symphyotrichum genus, b) moving several Eupatorium species into the Eutrochium genus, and c) collapsing several Andropogon species into Andropogon gerardii.  The latter case is the focus of this article.

A recent visit to the beaches of Presque Isle State Park, PA yielded an Andropogon species for which we were unfamiliar, given its 2-3′ foot stature, waxy feel, extensive clumping behavior, and unusual seed head formation.  In Pennsylvania, there are only four known Andropogon species, but the plant could have been a fifth. ArcheWild grows all of the local Andropogon species, but we just couldn’t figure this one out.  Perhaps there was an Andropogon species that we didn’t know…maybe a visitor from Canada?

Pennsylvania Andropogon species

Andropogon gerardii – A large native grass species usually found only in upland conditions and barrens systems.  Usually 5-6′ tall with a distinctive turkey-foot terminal seed head.

Andropogon glomeratus – A quite distinctive 2′ tall coastal plain species found mostly in Bucks County, at the opposite corner of the state from Presque Isle State Park.

Andropogon gyrans – Also a very distinctive 3′ tall and rare species found mostly in serpentine and shale barren systems and sporadically further south.

Andropogon virginicus – Common and quite recognizable.

Andropogon ternarius – A gorgeous 3′ tall species not documented in Pennsylvania (too bad), but is found in Maryland, Delaware, and New Jersey.  This is the species that that the Presque Isle species most looked like.

Andropogon furcatus

But the Andropogon species growing on the north shore of Presque Isle State Park looked like none of the known PA species, although it looked somewhat similar to Andropogon ternarius. Google to the rescue!

A search for ‘Andropogon Presque Isle’ yielded only one meaningful result, ‘A Botanical Survey of Presque Isle Erie County Pennsylvania by Otto E Jennings‘ wherein an unknown (to me) species was listed called Andropogon furcatus.  Viola!  To confirm, I consulted USDA only to find that the species is now listed as a synonym to Andropogon gerardii.  But the typical Andropogon gerardii and this Andropogon furcatus look, behave, and grow quite differently, hence this article.

Andropogon furcatus is growing in pure sand and creates large clumps that create small dunes near the shore.  They are less than half the height of East Coast populations of Andropogon gerardii, have a different seed head configuration, and have that waxy feel that you would expect from a species growing in pure sand.  See an image gallery of the Presque Isle Andropogon species below.

So why would the taxonomists lump this species with Andropogon gerardii? Well, I don’t know but is probably due to either some critical morphological distinction or genetic testing.  But I can tell you, it’s very different.

A species may be either a means or an end; properly it is both.

In descriptive botany, these two uses of the species have often been confused. The describing of new species has come to be recognized as an end in itself, while it should be nothing more than a necessary preliminary to further and more important botanical study. The interest of the ecologist in the proper recognition and naming of species is necessarily greater than that of nearly all other botanists. To him species are an indispensable means in the study of vegetation. On the other hand, the search for the definite results of adaptation and evolution, which is his final work, leads him inevitably to the species as an end.

It is this double significance of the species for the ecologist that makes him peculiarly concerned about its treatment. So long as he uses the species only as a means, he is not greatly confused, except as a consequence of the fact that species are habitually made in the herbarium upon a small number of specimens, while he meets them as hundreds and thousands of variable individuals in the wild.

His serious troubles begin with experimental work in adaptation and evolution. It quickly becomes evident that species so-called are widely different in rank, origin and relationship. Some are clearly species in the usual sense, while others are merely variations and forms of these. The ecologist thus comes to look with doubt upon all species. He accepts them reluctantly and provisionally until they meet successfully the test of experiment.

By Professor Frederic Clements, from An Ecologic View of the Species Conception

How to Refer to the Andropogon Species Growing at Presque Isle?

Ok, now, to the point of this article…

Say I work for the Pennsylvania Department of Conservation and Natural Resources, and I want to restore a worn-out beach and I love the mini dune-forming capability of this plant.  What do I order?

Well, according to the USDA, I would order seed or plugs of Andropogon gerardii.  But what would I receive?  Well, in probably all but the case of ordering from ArcheWild, I’d receive the 7-8′ tall Andropogon gerardii whose genes originated somewhere in the Midwest, since this is the plant that dominates the trade right now.  Is this the right way to go?  No.  So what should be put into the specification to get the plant that I really want for my restoration project?

I could say, “Andropogon grown from seed stock collected on the north shore of Presque Isle,” but although this is perhaps be the most accurate way to state the requirement, this might not be possible given that Presque Isle is a state park and collecting plant materials there is forbidden.

There are really only two options.

  1. Specify the defunct Andropogon furcatus species and hope that the supplying nursery gets you the right plant, or
  2. Specify Andropogon gerardii – 083a.  Including the species name AND the Ecoregion requirement provides some assurance that the seeds for the project will originate from along the southern shore of Lake Erie, which should contain the right genetic makeup to perform properly in the restoration effort.
Ecoregion 083a
Ecoregion 083a

Which is better?

Well, the former requires that you’re working with a nursery that knows what you’re doing and is doing everything possible to help you.  It also precludes using any mass-producing commercial nursery because they won’t have any idea what Andropogon furcatus means.

The latter option, naming both the species and the Ecoregion, allows any truly competent native plant nursery to supply the material.

Both methods would work but, actually, the latter is more specific and more consistent with emerging best-practices in the native plant nursery industry.  Specifying the plant species AND the Ecoregion from which the seed must orginate provides the best, scalable, way forward for getting the best genes possible for a restoration project.