Sisymbrium loeselii
Encyclopedia
Sisymbrium loeselii is a species of flowering plant in the mustard family
known by several common names, including small tumbleweed mustard, tall hedge mustard, and false London rocket. It is native to Eurasia, and it is known on other continents as an introduced species
and in some areas a common roadside weed
. It is an annual herb producing a hairy, erect stem which can exceed a meter in height. The leaf blades are divided into triangular, lance-shaped, and toothed linear lobes, and are borne on petioles
. The top of the stem is occupied by a raceme
of flowers with bright yellow petals each measuring just under a centimeter long. The fruit is a silique
up to 3.5 centimeters in length containing tiny seeds.
This plant is allelopathic
against other species growing around it. It produces chemicals that inhibit the germination
of seeds of other species, including bluebunch wheatgrass (Pseudoroegneria spicata) and Idaho fescue
(Festuca idahoensis). It also inhibits arbuscular mycorrhiza
l fungus species, such as Glomus intraradices
.
Brassicaceae
Brassicaceae, a medium sized and economically important family of flowering plants , are informally known as the mustards, mustard flowers, the crucifers or the cabbage family....
known by several common names, including small tumbleweed mustard, tall hedge mustard, and false London rocket. It is native to Eurasia, and it is known on other continents as an introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
and in some areas a common roadside weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
. It is an annual herb producing a hairy, erect stem which can exceed a meter in height. The leaf blades are divided into triangular, lance-shaped, and toothed linear lobes, and are borne on petioles
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
. The top of the stem is occupied by a raceme
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...
of flowers with bright yellow petals each measuring just under a centimeter long. The fruit is a silique
Silique
A silique or siliqua is a fruit of 2 fused carpels with the length being more than three times the width. The outer walls of the ovary usually separate when ripe, leaving a persistent partition...
up to 3.5 centimeters in length containing tiny seeds.
This plant is allelopathic
Allelopathy
Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial or detrimental effects on the target organisms...
against other species growing around it. It produces chemicals that inhibit the germination
Germination
Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...
of seeds of other species, including bluebunch wheatgrass (Pseudoroegneria spicata) and Idaho fescue
Festuca idahoensis
Festuca idahoensis is a species of grass known by the common names Idaho fescue and blue bunchgrass. It is native to western North America, where it is widespread and common...
(Festuca idahoensis). It also inhibits arbuscular mycorrhiza
Arbuscular mycorrhiza
An arbuscular mycorrhiza is a type of mycorrhiza in which the fungus penetrates the cortical cells of the roots of a vascular plant....
l fungus species, such as Glomus intraradices
Glomus intraradices
Glomus intraradices is an arbuscular mycorrhizal fungus used as a soil inoculant in agriculture and horticulture. In addition, it is one of the best mycorrhizal varieties of fungi available to mycoforestry, but it "has virtually no market value as an edible or medicinal mushroom" Glomus ...
.