Rudbeckia hirta
Encyclopedia
Rudbeckia hirta, the Black-eyed Susan, with the other common names of: Brown-eyed Susan, Brown Betty, Brown Daisy (Rudbeckia triloba), Gloriosa Daisy, Golden Jerusalem, Poorland Daisy, Yellow Daisy, and Yellow Ox-eye Daisy. It is a 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...

 in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Asteraceae
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...

. It is an upright 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...

 (sometimes biennial
Biennial plant
A biennial plant is a flowering plant that takes two years to complete its biological lifecycle. In the first year the plant grows leaves, stems, and roots , then it enters a period of dormancy over the colder months. Usually the stem remains very short and the leaves are low to the ground, forming...

 or 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...

) native to most of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, and is one of a number of plants with the common name Black-eyed Susan
Black-eyed Susan
Black-eyed Susan may refer to one of several things:Flowers* Rudbeckia hirta, a member of the sunflower tribe of the large family Asteraceae* A number of other members of the genus Rudbeckia* Hibiscus trionum in the family Malvaceae...

 with flowers having dark purplish brown centers. Black-eyed Susans can be established, like most other wildflowers, simply by spreading seeds throughout a designated area. They are able to reseed themselves after the first season.

Etymology

The genus name honors Olaus Rudbeck
Olof Rudbeck the Younger
Olaus Rudbeckius, junior or Olof Rudbeck , Swedish explorer and scientist, son of Olaus Rudbeck Sr, Rudbeck Jr. succeeded his father as professor of medicine at Uppsala University. Young Rudbeck was an able botanist and ornithologist who took his doctor's degree in Utrecht in 1690...

, who was a professor of botany at the University of Uppsala in Sweden and was one of Linnaeus's teachers. The specific epithet refers to the trichomes (hairs) occurring on leaves and stems.

Growth

The plant can reach a height of 1 m. It has alternate, mostly basal leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 10-18 cm long, covered by coarse hair. It flowers from June to August, with 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...

s measuring 5-8 cm in diameter (up to 15 cm in some cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s), with yellow ray florets circling a brown, domed center of disc floret
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....

s.

Varieties

There are four varieties
Variety (biology)
In botanical nomenclature, variety is a taxonomic rank below that of species: as such, it gets a three-part infraspecific name....

:
  • Rudbeckia hirta var. angustifolia. Southeastern United States (South Carolina to Texas).
  • Rudbeckia hirta var. floridana. Florida, endemic.
  • Rudbeckia hirta var. hirta. Northeastern United States (Maine to Alabama).
  • Rudbeckia hirta var. pulcherrima. Widespread in most of North America (Newfoundland to British Columbia, south to Alabama and New Mexico; naturalized Washington to California).

Symbolism and uses

The Black-eyed Susan was designated the state flower
Floral emblem
In a number of countries, plants have been chosen as symbols to represent specific geographic areas. Some countries have a country-wide floral emblem; others in addition have symbols representing subdivisions. Different processes have been used to adopt these symbols - some are conferred by...

 of Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...

 in 1918.

Butterflies are attracted to Rudbeckia hirta when planted in large color-masses.

Numerous cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s have been selected for garden
Garden
A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has...

 planting; some popular ones include 'Double Gold', 'Indian Summer', and 'Marmalade'.

The roots but not seedheads of Rudbeckia hirta can be used much like the related Echinacea purpurea
Echinacea purpurea
Echinacea purpurea is a species of flowering plant in the genus Echinacea. Its cone-shaped flowering heads are usually, but not always purple. It is native to eastern North America and present to some extent in the wild in much of the eastern, southeastern and midwest United States...

. It is an astringent
Astringent
An astringent substance is a chemical compound that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin adstringere, meaning "to bind fast"...

 used as in a warm infusion as a wash for sores and swellings. The Ojibwa
Ojibwa
The Ojibwe or Chippewa are among the largest groups of Native Americans–First Nations north of Mexico. They are divided between Canada and the United States. In Canada, they are the third-largest population among First Nations, surpassed only by Cree and Inuit...

 used it as a poultice
Poultice
A poultice, also called cataplasm, is a soft moist mass, often heated and medicated, that is spread on cloth over the skin to treat an aching, inflamed, or painful part of the body. It can be used on wounds such as cuts...

 for snake bites and to make an infusion
Infusion
An infusion is the outcome of steeping plants with desired chemical compounds or flavors in water or oil.-History:The first recorded use of essential oils was in the 10th or 11th century by the Persian polymath Avicenna, possibly in The Canon of Medicine.-Preparation techniques:An infusion is very...

 for treating colds and worms in children. The plant is diuretic
Diuretic
A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...

 and was used by the Menominee
Menominee
Some placenames use other spellings, see also Menomonee and Menomonie.The Menominee are a nation of Native Americans living in Wisconsin. The Menominee, along with the Ho-Chunk, are the only tribes that are indigenous to what is now Wisconsin...

 and Potawatomi
Potawatomi
The Potawatomi are a Native American people of the upper Mississippi River region. They traditionally speak the Potawatomi language, a member of the Algonquian family. In the Potawatomi language, they generally call themselves Bodéwadmi, a name that means "keepers of the fire" and that was applied...

. Juice from the roots had been used as drops for earaches.

The plant contains anthocyanins.
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