Native Plant Glossary
Let’s breakdown some of the fancy terms you’re hearing thrown around. Why do we only say Latin names? Why are there different words for roots? What’s the difference between invasive species and aggressive species?
TERM TOOLBOX
On this page:
Native vs Naturalized plants
Invasive vs. Aggressive plants
Plant Life Cycle Terms
Root Terms
Naming Conventions
Native vs Naturalized
Native plants evolved in the place that they live, and existed here prior to European colonization. Because of this millennia-long history, they evolved along with the other plants, insects, mycorrhizae and animals that lived with them prior to colonization, and over millennia their life cycles have intertwined to depend on each other.
Naturalized plants evolved somewhere, but arrived somewhere ELSE (usually through human intervention), and began to thrive there without the help of people. Because they have been removed from the web of organisms they evolved with, they usually have few predators/consumers, and as a result naturalized plants are highly successful outside of their native environment, sometimes dominating landscapes and wild areas. They also rarely benefit specialist pollinators (30% of native bees), or the larva of insects like butterflies and moths, because they did not evolve as a part of their food chains.
Invasive vs Aggressive
Three criteria must be met for a species to be deemed invasive. Invasive plants:
- originated and evolved outside the ecosystems where they’re found
- reproduce without human intervention, and
- dominate local ecosystems, causing damage to ecosystems and displacement of native species
These criteria mean that species that are native to Ontario CANNOT BE INVASIVE, regardless of how aggressively (or unwantedly) they grow. Invasive species lists differ by different jurisdictions, and some species are invasive in some places and controlled by environmental factors in others. Climate change is expanding the areas where exotic species can proliferate, and warming temperatures are changing the growing conditions in Ontario and the behaviour of exotic plants, expanding the number of species that could invade ecosystems here. In Ontario, no meaningful legislation currently exists to prevent or regulate the sale or distribution of invasive plants, and they are regularly sold in nurseries, recommended by horticulturalists and planted by landscapers and developers. Under current legislation, invasive species do not have to be labelled, identified or flagged.
Aggressive species grow and spread vivaciously, rapidly, densely or far. Invasive species can be aggressive, but not all aggressive species are invasive. Some native plants spread aggressively, which can make them challenging to use in garden settings, but because they have evolved here, they still participate in local food webs, service specialist pollinators, and serve specific and important ecosystem functions–and their populations are held in check eventually through predation and competition succession systems that have developed over thousands of years. Aggressive plants can be very helpful in rebalancing an ecosystem after the removal of invasive species.
Plant Life Cycle Terms
Annual: a plant that completes its entire life cycle in one growing season. It germinates, grows, fruits and seeds, and dies; after winter, it does not return. Annuals generally grow faster than other plants, because they have less time to attain the same evolutionary goals.
Biennial: a plant that germinates and grows in one growing year, then flowers, seeds and dies in the next growing year. Many biennials spend year 1 as low-growing basal rosettes, and grow and flower spectacularly during year 2. Many biennials also produce large volumes of seed to ensure the survival of their species. To maintain a patch of biennial plants, ensure to spread their seed into bare soil in the fall.
Short-lived perennial: a plant that lives slightly longer than 2 year biennials. They often flower quickly and produce large volumes of seed to ensure the survival of the species.
Perennial: a plant that returns year after year from the same root system. Perennials take time to establish because they need to survive the winter; the first year or two energy is directed to root development; the following year is foliage development; the years after, blooms and seeds. Some species of Native Ontario perennials can live up to 20 years in ideal conditions.
Root Terms
Corm: a corm is a small bulb that stores energy for a plant to use for the next growing season. A corm’s energy is depleted by sprouting every year, and the plant needs to make a new corm to replace it to survive the next year. Corm-based plants often take several years to grow from seed, because they need to develop the seed into a corm first. Notable corm-forming Ontario native species include erythronium americanum/trout lily, trillium grandiflorum/trillium, lilium michiganense/Michigan lily, and camassia scilloides/wild hyacinth.
Fibrous roots: plants that grow spidery, thin and numerous roots are described as having “fibrous” root systems. Plants with fibrous roots are extremely good for erosion control and soil cohesion, as well as for increasing the water permeability of soil.
Rhizome: a rhizome is a fleshy root that spreads laterally through the soil. Rhizomes often sprout their own stems, and rhizomatous spreading species can colonize areas of ground rapidly by stretching rhizomes out and pushing several stems up along the length of the rhizome. Rhizomatous spreaders can be very beneficial for ensuring soil stability and preventing encroachment of invasive species. Common rhizomatous native Ontario plants include viola sororia/common blue violet, solidago Canadensis/Canada goldenrod, and Asclepias syriaca/common milkweed.
Stolons/Runners: stolons or runners are structures that stretch a node out from the parent plant across the ground, so it can root and create a new plant. Because runners/stolons create clones of the parent plant, stoloniferous plants also utilize additional sexual reproductive strategies like fruiting/seeding. Ontario native species that often root by stolons include tiarella cordifolia/foamflower, fragaria spp/ native strawberries, and Argentina anserina/silverweed.
Taproot: species with a taproot form a large, vertical central root stalk that can penetrate the soil very deeply. The taproot stores nutrients and energy for the plant, and supports its growth. Species with taproots react poorly to being transplanted because it can destroy the root. Taprooted species are also often drought-resistant and tolerant of poor soils. When a taprooted plant dies, the root degrades and contributes large volumes of organic material into the soil.
Tuber: a tuber is a root structure specifically developed to store nutrients for use by the plant. Tuberous plants can make copies of itself through the nodes (“eyes”) of the tuber. Tuberous plants generally expand in clumps, and are often easy to divide. Examples of tuberous Ontario native plants include apios americana/groundnut vine and helianthus tuberosus/sunchoke sunflower.
Exotic species: originate from places that are from far away, frequently from a different continent. Species that evolved in Europe, Asia, Africa, South America, the Caribbean and Australasia are all exotic to continental North America.
Legumes: leguminous plants create colonies of beneficial bacteria that fix nitrogen into the soil. They’re very useful for soil remediation, for improving the health, yield and organic balance of soil, and improving the health of the plants around them. Legumes can usually be identified by their rounded leaves, and their pea-like seeds and pods.
Near-native species: species that evolved in a place similar to AND geographically close to a location, but are not historically recorded as present in that location. While many of the plants native to the Great Lakes Ecoregion are not historically native to Simcoe County, they coevolved with the same insects and food webs that exist here, and are beneficial to the ecosystem for that reason.
Naming Conventions
Botanical binomial: a system for naming botanical species regulated by the scientific community. Each plant is allocated a name consisting of two words: a genus (shared by the close relatives of that plant), and a species (unique to that particular plant).
Common name: an unregulated name that a plant is called. Several plants may share the same common name (ie. black Eyed Susan, Snake Root)…you can basically call any plant anything as a common name.
Cultivar: when a plant is selectively bred, crossed with another species, or cloned, to emphasize a particular trait, it is called a Cultivar. Cultivars are denoted with an additional name or modifier “in quotations” on the label of the plant: Monarda Punctata is a native plant, but Monarda Punctata “Punky Brewster”, Spotted bee balm “Rockin’ Whoville”, or Dotted horsemint “Short and Sweet” would be cultivars. Cultivars are a key way that large traditional nurseries make money, because you can own the trademark on a cultivar, but you cannot trademark a naturally evolved species that you had no hand in creating. Cultivars are less beneficial to ecosystems than straight species: they are frequently sterile/ do not produce seed; changes to bloom colour can confuse pollinators; changes to foliage colours render the plant inedible to larva; changes to the number of petals on a flower renders pollen inaccessible to pollinators; cross breeding between straight species and cultivars can contaminate the genetics of the straight species. Infrequently, cultivars can improve the pollen or nectar concentration of plants, but studies are lacking and virtually zero firms producing cultivars for sale investigate their work’s effects on ecosystems or pollinators. If you absolutely must choose a cultivar over a native species, the changes with the least detrimental effect appear to be selections for height (taller or shorter), and selections for bloom colour (but NOT shape or size).
Nativar: a cultivar with a native plant species as its starting point. Some are clones of naturally occurring mutants (i.e. Swamp Milkweed “Ice Ballet”), but some are selective-bred on purpose in the exact ways that traditional horticultural cultivars are. They are denoted by the same “modifiers in quotations” that regular cultivars are.
Straight species: a straight species is a plant as it evolved, without human intervention.