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Black eyed Susan

Rudbeckia hirta

Basic Details

Description

Floral Formula

Features

Translations

Basic Details

NameBlack eyed Susan

DescriptionCheerful native wildflower featuring bright golden-yellow ray petals surrounding a prominent dark brown to black central cone. Blooms prolifically from early summer through fall, creating masses of sunshine-colored flowers that sway on sturdy stems. A quintessential American wildflower beloved for its carefree nature, attracting butterflies and bees while providing seeds for goldfinches and other birds.

FamilyAsteraceae

GenusRudbeckia

TribeHeliantheae

Floral Formula & Features

Floral FormulaRay florets - Br % ♀ K C∞ A0 G(1), Disk florets - Br ⊕ ⚥ K C(5) A5 G(1)

Ray florets - Bract Present, female flower, Bilaterally symmetrical, 0 Pappus (customized sepals), Numerous Petals, no stamens, 1 carpel with inferior ovary. Disk Florets - Bract present, Radially symmetrical, bisexual, 5 fused petals, 5 free stamens, 1 carpel with inferior ovary

Features

Name 'Black-eyed Susan' refers to the dark chocolate-brown central cone resembling a black eye. 'Rudbeckia' honors Swedish botanists Olof Rudbeck father and son. 'Hirta' means hairy, describing the rough, bristly texture of stems and leaves
Composite flower head (capitulum) 2-3 inches (5-7 cm) across with 8-21 golden-yellow ray florets surrounding a raised, dome-shaped center of dark brown disc florets. Flowers held on sturdy, hairy stems above foliage
Short-lived perennial or biennial, often behaving as annual. Blooms from June through October with peak flowering in mid to late summer. Self-seeds readily, naturalizing in meadows and roadsides. Maryland's state flower
Grows 1-3 feet (30-90 cm) tall with 12-18 inch (30-45 cm) spread. Lifespan of 1-3 years but perpetuates through self-seeding. Propagated easily from seed (germinates in 7-14 days) or division
Native to eastern and central North America from Nova Scotia to Colorado, south to Florida and Texas. Found in prairies, meadows, open woodlands, and disturbed sites. Now naturalized across much of North America
Thrives in full sun with at least 6 hours of direct sunlight. Adaptable to various soil types including poor, dry soils. Drought tolerant once established but performs best with moderate moisture. Heat and humidity tolerant
Excellent cut flower lasting 7-10 days in vase. Attracts bees, butterflies, and other pollinators. Seeds provide food for goldfinches, chickadees, and other songbirds in fall and winter. Deer and rabbit resistant. Used in prairie restoration and wildflower meadows

Names in Different Languages

Latin / ScientificRudbeckia hirta

English (Alternate)Black-eyed Susan, Brown-Eyed Susan, and Yellow Ox-Eye Daisy

Hindiकाला मत सुसान (kaala mat susaan)

Tamilமஞ்சள் கொடியன் (Manjal Kodiyan)

Teluguగురుగింజ (guriginja), అతిమధురము (atimadhuramu), గుంజ (gunja), కుక్కుటము (kukkutamu), ముక్కుటము (mukkutamu), రక్తిక (raktika), సిన్న గురుగింజ (sinnaguruginja)

Malayalamകരിങ്കണ്ണി (karin kani), സൂസന (susan)

Kannadaಕಪ್ಪು ಕಣ್ಣಿನ ಸುಸಾನ್ (kappu kannina susaan)

Sanskritरुडबेकिया हिर्ता (rudabekia hirta)

Bengaliগোল্ডেন জারুসেলম (Goldeun Jarasalem)

Frenchrudbeckie tardive, marguerite jaune (yellow daisy), rudbeckie hérissée (hairy coneflower)

Russianчерноглазка (chernoglazka), черноока (chernookah)

Spanishla rudbeckia

GermanSonnenhut, Rudbeckien

What is Floral Formula?

A floral formula is a symbolic representation of a flower's structure using letters, numbers, and special symbols. It provides a concise way to describe the arrangement and number of floral parts.

Example Formula

% K(6) C1+2+(2) A(9) G₂

This formula describes the flower's symmetry, sepals, petals, stamens, and carpels in a standardized format.