Alyssum is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of about 100–170 species of flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

s in the family Brassicaceae

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....

, native to Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

, and northern Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

, with the highest species diversity in the Mediterranean region. The genus comprises annual

Annual plant

An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...

 and perennial

Perennial plant

A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...

 herbaceous

Herbaceous

A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...

 plants or (rarely) small shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

s, growing to 10–100 cm tall, with oblong-oval leaves and yellow or white flowers (pink to purple in a few species).

The genera Lobularia

Lobularia

Lobularia is a genus of four or five species of flowering plants in the family Brassicaceae, closely related to the genus Alyssum....

and Aurinia

Aurinia

Aurinia is a genus of flowering plant of the family Brassicaceae.-Species:There are three species in the genus.*Aurinia corymbosa*Aurinia petraea*Aurinia saxatilis...

are closely related to Alyssum and were formerly included in it. The widely cultivated species popularly known as "Sweet Alyssum" is Lobularia maritima

Lobularia maritima

Lobularia maritima, common name Sweet Alyssum or Sweet Alison, also commonly referred to as just Alyssum from the genus in which it was formerly classified, is a low-growing flowering plant in the family Brassicaceae.-Etymology:...

. The common rockery plant is Aurinia saxatilis

Aurinia saxatilis

Aurinia saxatilis Aurinia saxatilis Aurinia saxatilis (Basket of Gold, Goldentuft alyssum, Golden Alyssum, Gold-dust, Golden-tuft alyssum, Golden-tuft madwort, Rock madwort; syn. Alyssum saxatile L., Alyssum saxatile L. var...

.

Alyssum foliage is used as food by the caterpillar

Caterpillar

Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...

s of certain Lepidoptera

Lepidoptera

Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

, including Orthonama obstipata (The Gem).

Selected species

Alyssum alpestre Alyssum alyssoides Alyssum alyssoides Alyssum alyssoides is a species of flowering plant in the mustard family known by several common names, including pale madwort and yellow alyssum... Alyssum arenarium Alyssum argenteum Alyssum atlanticum Alyssum baeticum Alyssum bertolonii Alyssum borzaeanum Alyssum cadevallianum Alyssum caliacrae Alyssum calycocarpum Alyssum campostre Alyssum canescens Alyssum corsicum Alyssum corymbosoides Alyssum cuneifolium Alyssum dasycarpum Alyssum densistellatum Alyssum desertorum Alyssum desertorum Alyssum desertorum is a species of flowering plant in the mustard family known by the common name desert madwort. It is native to Europe and Asia, and it is found in parts of western North America as an introduced species and sometimes a weed. This is a hairy annual herb producing upright stems up... Alyssum diffusum Alyssum doerfleri Alyssum euboeum Alyssum fallacinum Alyssum fastigiatum Alyssum fedtschenkoanum Alyssum fischeranum Alyssum foliosum Alyssum fragillimum Alyssum fulvescens Alyssum granatense

Alyssum gustavssonii Alyssum handelii Alyssum heldreichii Alyssum heterotrichum Alyssum hirsutum Alyssum homalocarpum Alyssum idaeum Alyssum lanceolatum Alyssum lapeyrousianum Alyssum lassiticum Alyssum lenense Alyssum ligusticum Alyssum linifolium Alyssum longicaule Alyssum longistylum Alyssum macrocarpum Alyssum marginatum Alyssum markgrafii Alyssum minus Alyssum minutum Alyssum moellendorfianum Alyssum montanum Alyssum murale Alyssum nebrodense Alyssum nevadense Alyssum obovatum Alyssum obtusifolium Alyssum ovirense

Alyssum pulvinare Alyssum purpureum Alyssum pyrenaicum Alyssum repens Alyssum reverchonii Alyssum robertianum Alyssum rostratum Alyssum scardicum Alyssum serpyllifolium Alyssum sibiricum Alyssum siculum Alyssum simplex Alyssum smolikanum Alyssum smyrnaeum Alyssum sphacioticum Alyssum spinosum Alyssum stapfii Alyssum stribrnyi Alyssum szowitsianum Alyssum tavolarae Alyssum taygeteum Alyssum tenium Alyssum tenuifolium Alyssum tortuosum Alyssum turkestanicum Alyssum umbellatum Alyssum wierzbickii Alyssum wulfenianum

Formerly included

• Alyssum maritimum syn. Lobularia maritima
  Lobularia maritima
  Lobularia maritima, common name Sweet Alyssum or Sweet Alison, also commonly referred to as just Alyssum from the genus in which it was formerly classified, is a low-growing flowering plant in the family Brassicaceae.-Etymology:...
  
  
• Alyssum saxatile syn. Aurinia saxatilis
  Aurinia saxatilis
  Aurinia saxatilis Aurinia saxatilis Aurinia saxatilis (Basket of Gold, Goldentuft alyssum, Golden Alyssum, Gold-dust, Golden-tuft alyssum, Golden-tuft madwort, Rock madwort; syn. Alyssum saxatile L., Alyssum saxatile L. var...