Centaurea dealbata is a species of Centaurea

Centaurea

Centaurea is a genus of between 350 and 600 species of herbaceous thistle-like flowering plants in the family Asteraceae. Members of the genus are found only north of the equator, mostly in the Eastern Hemisphere; the Middle East and surrounding regions are particularly species-rich...

native to the Caucasus Mountains

Caucasus Mountains

The Caucasus Mountains is a mountain system in Eurasia between the Black Sea and the Caspian Sea in the Caucasus region .The Caucasus Mountains includes:* the Greater Caucasus Mountain Range and* the Lesser Caucasus Mountains....

. It is widely cultivated as an ornamental perennial.

Description

The flowers of C. dealbata resemble those of C. americana

Centaurea americana

Centaurea americana, commonly called American Starthistle or American Basketflower, is an annual native to the southern central United States and northeastern Mexico. Its common name comes from the underside of the inflorescence, which has a basket weave pattern on it and on the flowerbuds.The pink...

in color and form; the composite inflorescence

Inflorescence

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

 has rosy outer florets shading to cream in the center of the 2 in. disk, surrounded by scaly bract

Bract

In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...

s on a slender peduncle

Peduncle (botany)

In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...

 18 to 24 in. long. The blooming period is in early summer.

C. dealbata is most noteworthy for its leaves. Like those of C. moschata

Centaurea moschata

Centaurea moschata is an ornamental plant of the Asteraceae family....

they are divided, but unlike the latter the division is quite regular. The underside of the leaves is covered in silver hairs.

Cultivation

C. dealbata is widely cultivated as an ornamental, though it is not as well-known as some other members of the genus. It is widely adaptable and drought-tolerant. The flowers attract butterflies and bees. It self-seeds to a degree.

The variety 'Steenbergii' is recognized, and several cultivars are available.

Sources tracking 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...

species generally classify it as a "casual alien"; that is, it escapes from gardens but is not invasive. In some areas of the United States it has naturalized.