''Linaria dalmatica'' is a

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of ...

, short-lived

perennial plant In horticulture, the term perennial (''wikt:per-#Prefix, per-'' + ''wikt:-ennial#Suffix, -ennial'', "through the year") is used to differentiate a plant from shorter-lived annual plant, annuals and biennial plant, biennials. It has thus been d ...

native to western

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

and southeastern

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

that has become a weed in other areas. The family this plant now belongs to is the

Plantaginaceae Plantaginaceae, the plantain family or veronica family, is a large, diverse family (biology), family of flowering plants in the order Lamiales that includes common flowers such as Antirrhinum, snapdragon and Digitalis, foxglove. It is unrelated ...

Family. Previously, it belonged to the

Scrophulariaceae The Scrophulariaceae are a family of flowering plants, commonly known as the figwort family. The plants are annual and perennial herbs, as well as shrubs. Flowers have bilateral (zygomorphic) or rarely radial (actinomorphic) symmetry. The Scr ...

( Figwort) family. Its common names include Balkan toadflax, broadleaf toadflax, and Dalmatian toadflax. ''Linaria dalmatica'' has unique yellow flowers with an orange center that draw individuals to purchase them to display in their gardens. The distribution of ''L. dalmatica'' to North America can be attributed to use as a fabric dye, folk remedies and as an ornamental plant. However, it is now classified as a weed in both

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

and the

U.S. The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...

Invasive species

''Linaria dalmatica'' is listed as a

noxious weed A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is harmful to agricultural or horticultural crops, natural habitats or ecosystems, or humans or lives ...

in fourteen

U.S. states In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

and three provinces in Canada. However, it is present in thirty-one U.S. states and ten provinces and two territories in Canada. It is a grassland invader native to the Mediterranean region, and it was introduced to

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

in the late 1800s. It has fast-growing strong, horizontal roots, and can withstand cold, and is a problem for

farm A farm (also called an agricultural holding) is an area of land that is devoted primarily to agricultural processes with the primary objective of producing food and other crops; it is the basic facility in food production. The name is used fo ...

s and

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

s in the interior of

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

Etymology

The genus name ''

Linaria ''Linaria'' is a genus of almost 200 species of flowering plants, one of several related groups commonly called toadflax. They are annuals and herbaceous perennials, and the largest genus in the Antirrhineae tribe of the plantain family Plant ...

'', appears to stem from the Latin word linum, meaning

flax Flax, also known as common flax or linseed, is a flowering plant, ''Linum usitatissimum'', in the family Linaceae. It is cultivated as a food and fiber crop in regions of the world with temperate climates. In 2022, France produced 75% of t ...

, as some

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

have leaves that appear flax-like. The species name ''dalmatica'' means

Dalmatia Dalmatia (; ; ) is a historical region located in modern-day Croatia and Montenegro, on the eastern shore of the Adriatic Sea. Through time it formed part of several historical states, most notably the Roman Empire, the Kingdom of Croatia (925 ...

which is located on the

Balkan Peninsula The Balkans ( , ), corresponding partially with the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throug ...

Habitat

''L. dalmatica'' have adapted to a wide range of conditions and can commonly be found in growing on roadsides,

valleys A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a ve ...

, gravel pits, fields, pastures and overgrazed or deteriorated rangelands to name a few. They tend to thrive in open areas that are not well-kept and disturbed soils.

Description

Seeds

Seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

production of ''L. dalmatica'' is dependent on many factors such as environmental conditions and competition sites. In sites with favourable conditions (moisture availability) and low competition of other plants, up to 500,000 seeds can be produced per

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

. Seeds are small and appears black to purplish-brown in colour.

Seed dispersal In spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

can be through a number of ways including wind,

wildlife Wildlife refers to domestication, undomesticated animals and uncultivated plant species which can exist in their natural habitat, but has come to include all organisms that grow or live wilderness, wild in an area without being species, introdu ...

and seed ingestion by

animal Animals are multicellular, eukaryotic organisms in the Biology, biological Kingdom (biology), kingdom Animalia (). With few exceptions, animals heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, ...

s. Seeds tend to germinate in the spring, however they can also

germinate Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an flowering plant, angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the sp ...

in the fall. The weight and development of seeds are influenced by the environment in which they grow, where growth is significantly impacted by moisture availability. With low moisture availability or drought conditions, growth may be inhibited as ''Linaria dalmatica'' are weak competitors in these conditions. Development of seeds are typically slow to begin with but increase with time.

Roots

''L. dalmatica'' has an extensive root system. The

root In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...

s of ''L. dalmatica'' make it a strong competitor as they can produce long and deep

taproot A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproot ...

s that are able to obtain take control of resources required for growth such as moisture and nutrients. In addition, lateral roots also arise from the buds present on the roots that contribute to the plants ability to obtain resources. These lateral roots can grow up to 10 feet away from the parent plant. The roots are a great storage place for energy and they possess the greatest amount of energy storage in the fall, storing sugars (i.e.

fructose Fructose (), or fruit sugar, is a Ketose, ketonic monosaccharide, simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and gal ...

and

glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...

). Contrastingly, the least amount of energy stored in the roots occur in June just as the flowers are set to bloom. ''L. dalmatica'' also produce creeping roots which appear white in colour. These roots allow for a rapid rate of reproduction of these plants.

Leaves

Leaves are broad and heart-shaped and are arranged in an alternating pattern. The leaves are attached to the stem ascending outward and are smooth, waxy and

glabrous Glabrousness () is the technical term for a lack of hair, down, setae, trichomes, or other such covering. A glabrous surface may be a natural characteristic of all or part of a plant or animal, or be due to loss because of a physical condition, ...

. In addition, they do not have petioles.

Flowers

Flowers are

raceme A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...

and are composed of five

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s and five

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s (

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s), four pairs of

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s of unequal length and

pistils Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...

are bicarpellate. Flowering of ''L. dalmatica'' takes place from late May to September. The flowers are

bilaterally symmetrical Symmetry in biology refers to the symmetry observed in organisms, including plants, animals, fungi, and bacteria. External symmetry can be easily seen by just looking at an organism. For example, the face of a human being has a plane of symme ...

and have spurs pointing downwards.

Control and management

As ''L. dalmatica'' are regarded as a

, determining solutions to manage and control the growth is essential. Due the high adaptability of ''L. dalmatica'', they are able to outcompete plants and thus remain present and utilize all the resources required for growth. It is critical to remove these plants at their most vulnerable stage which is when it is at its seed stage. Hence methods to remove ''L. dalmatica'' are essential to prevent seed formation preceding flowering.

Chemical control

The use of

herbicide Herbicides (, ), also commonly known as weed killers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page f ...

s are effective to remove weeds, however, when used on ''L. dalmatica'' results of this chemical control vary. Herbicide control of ''L. dalmatica'' seems to be short-term as the leaves waxy surface help prevent herbicide uptake and its potency. Furthermore, its extensive

root system In mathematics, a root system is a configuration of vector space, vectors in a Euclidean space satisfying certain geometrical properties. The concept is fundamental in the theory of Lie groups and Lie algebras, especially the classification and ...

aids in reproduction when herbicides manage to remove the flowering plant. It is recommended herbicide use is the most effective pre-bloom or in the death stages of ''L. dalmatica.'' Herbicide use as these stages can promote long-term control and have a greater impact on the removal of these plants as energy storage in the roots are at its least.

Mechanical control

Manual labour Manual labour (in Commonwealth English, manual labor in American English) or manual work is physical work done by humans, in contrast to labour by machines and working animals. It is most literally work done with the hands (the word ''manual ...

of removing ''L. dalmatica'' by digging up the roots by hand and with a shovel. It is important to note, this is effective but require many years to suppress and remove all ''L. dalmatica'' plants.

Biological control

The release of insects feeding on the leaves and stems of ''L. dalmatica'' is an additional way to control the rapid

reproduction Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: Asexual reproduction, asexual and Sexual ...

of this plant and localize it to a certain area. The most prominent insect that aids in the suppression of ''L. dalmatica'' growth is the toadflax stem-mining weevil. The toadflax stem weevil has been vital in the disruption of nutrient and water transport as

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e laid by the toadflax stem weevil feed on the stem while the developed adults feed on the leaves. The disruption of the resources used for growth inhibits the bloom of some flowers and therefore reduces the production of seeds. Additionally, shoot growth is inhibited as they wither before they reach growth due to insufficient nutrients and water. Additional insects that feed on the ''L. dalmatica'' and used as a biological control are the '' Brachypterolus pulicarius, Gymnaetron antirrhini and Rhinusa neta'' and ''Mecinus janthinus''.

Cultural control

The use of cultural control alone is not effective but in combination with other controls such as chemical promote greater success in controlling ''L. dalmatica''. The methods of burning and tilling may be effective alongside the spraying of herbicides. The addition of other competitive plants to compete with ''L. dalmatica'' can also promote the removal of this noxious weed. It is important to note that control through cultivation must be persistent and engaged in for at least two years to improve effectiveness of removal.

Toxicity

Regarding the toxicity level of ''L. dalmatica,'' there is a lack of information to determine if it is toxic or not to both animals and humans. For animals, exposure and consumption of this plant is observed to be relatively low as it is not there preferred forage although grazing does occur. However, it is proposed that due to quinolizidine alkaloids present within the plant, it will cause acute poisoning and other health effects in animals as it has been displayed in sheep and cattle. Further experiment and testing is required to determine the toxicity significance in both animals and humans.

References

External links

Species Profile- Dalmat
''L. L. damatica''.L''dalmaticaL. dalmatica''of ''L. dalmatica'' ''L. dalmatica'
ax (''Linaria dalmatica'')
National Invasive Species Information Center,

United States National Agricultural Library The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Locate ...

. {{Authority control dalmatica Plants described in 1753 Taxa named by Carl Linnaeus Taxa named by Philip Miller