Native, Species, Cultivar, Nativar, or Let's call the whole thing off!

Recently I wanted to find this document in order to share it with a group of native plant nurseries that are working to form a cooperative in Maine. More on that very soon. I feel like it is still a pretty thorough overview of certain definitions that pertain to how plants are classified and particularly in relationship to plants one might find for sale in a nursery or garden center. I hope you find it useful. And, as usual, all errors are my own. If you are a botanist, please let me know where I have gone awry. Thank you!

Native, Species, Cultivar, Nativar or Let’s call the whole thing off!

Native: There are many definitions of this term with respect to gardening and plants. One accepted and often used definition in the United States is that a native plant is a plant that existed in a certain area prior to European settlement on the North American continent. The “certain area” in question is defined in many ways. Native east of the Mississippi, native to Appalachian spine, native to the southern United States, native to Maine, native to Waldo County, native to a particular eco-region and on and on. This does not mean the plants imported (introduced) on purpose or by accident through human exodus are not unimportant. They are simply important for different reasons and can be harmful to their new environment if they take up space needed for native plants. This is because native plants are adapted to and have evolved with native insects, birds, and animals and the visitors from away have not. 

Here is a general definition I (sort of) like “Native plants should be defined as those that have evolved and adapted to a specific location and have remained genetically unaltered by humans” (Wasowski, The American Gardener, 1998 – taken from www.wildflower.org, the website for the Ladybird Johnson Wildflower Center). The reason this definition is useful for my purposes (although not perfect) is that I encourage planting native species in order to support the wildlife with which they have co-evolved. Therefore, I consider plants native to a certain area as the primary food sources for the wildlife in that area, and in particular, specialist pollinators, as well as (and most importantly) insects at the larval stage. It's all about baby food! Baby insects need native plant leaves to eat and baby birds need lots and lots of baby insects to eat.

The following definitions for species, cultivar, variety, and selection are adapted from the New Moon Nursery website.

Species: 

Species is a group of plants having common characteristics that differentiate them from others in the same genus. Species is the basic unit of classification in botany. These plants breed amongst themselves and will come true from seed. For example:

Amsonia tabernaemontana

Cultivar: 

A cultivar is a hybrid name derived from the term Cultivated Variety. It is applied to a plant that has originated and persisted under cultivation (as distinct from a species, which evolves naturally in an ecosystem). A cultivar name appears after the species name and is set off by single quotation marks. Crosses and most cultivars will not come true from seed. They are propagated by cuttings or tissue culture. What this means is every generation of the plant is EXACTLY the same. A clone. No genetic diversity can be introduced, which makes the plants often more vulnerable to disease. If plants such as this cross with species plants, the resulting plants can lose important attributes and decrease the ecological services the plants provide to co-evolved species such as insects, birds, and mammals.

cv = cultivar, cvs = cultivars, x = cross

Amsonia tabernaemontana ‘Storm Cloud’

This is a Proven Winner registered trademark plant 

You can also see something like this: Delphinium x ‘-----------------------‘. The x usually indicates that two species in the same genus have been crossed.

A Selected Variety:

Selected varieties are a bit different than crosses and other hybridization. A variety has distinct features that make it more attractive to humans, but not sufficiently distinct enough to fall into their own species category. Often these are plants of a species that have developed in a particular ecoregion or have naturally mutated from a native population. Humans often encourage these natural varieties. For example, Amsonia tabernaemontana var. salicifolia.

Selecting by seed: 

Hybridizers often collect seed from plants with particularly attractive attributes and through successive generations keep selecting seedlings and saving seed to encourage those attributes until a predictable seedbank has been achieved. Plants developed this way will come true from seed. Certain attributes of such plants do not diminish their ecological services potential. However, attributes, such as leaf color and thickness can confuse insects, and ultimately render a plant useless for larval plant food.

The more the plant has been altered through hybridization, the less likely that its ecological services potential will remain intact. If there is no pollen, or a double flower, or the plant flowers at a different time, or its leaves are a new color, or a different texture, or even if the plant is a different height can all impact the ability of the plant to support pollinators and larvae. 

Nativar:

Nativar is a marketing term without meaning. It refers to a cultivar of a native plant. A cultivar is a cultivar regardless of where the plant originated. Please see the definition of cultivar above.

Now What, Astrid?

What I recommend is: 

-to plant as many straight species as possible.

-to research where a species is native and use judgement when selecting plants. There are recommendations such as aim for 70% native species and 30% cultivars and/or non-native species, for example. However, there are other factors to consider, such as aggressiveness. 

-become familiar with the invasive species in your area and remove them.

-to plant adaptable species that require less inputs, in places on your landscape that meets their natural requirements.

-to decrease the size of the lawn, allowing for human fun and leisure, of course, but with the aim of providing useful habitats for all of the other creatures with whom we share this amazing place.

-to plant in layers: groundcovers, perennials, shrubs, and trees. Create living mulch with plants.

-to use as little supplemental water as possible, BUT to provide water sources for wildlife whenever possible.

-to be a little messier as this provides habitat for all manner of creatures.

-to forgo all pesticides and aim for an ecological balance. Remember, munched-on leaves most often mean you are providing the needed baby food (for Monarch caterpillars, for example) and if you don’t have aphids, ladybug babies won’t have the opportunity to eat them.