black-eyed Susan

Names and Synonyms

Common Names

• black-eyed Susan
• hairy coneflower
• Black-Eyed-Susan
• black-eyed coneflower
• blackeyed Susan
• brown betty
• common black-eyed Susan

Scientific Names

Accepted name

Synonyms

• Centrocarpha hirta
• Helianthus hirtus
• Peramibus hirtus
• Coreopsis hirta

Regional and Traditional Names

Sources: Wikidata, Catalogue of Life

Taxonomical Classification

This plant belongs to the kingdom Plantae and the phylum Streptophyta, falling under the class Equisetopsida and subclass Magnoliidae. Within the order Asterales, it is classified under the family Asteraceae and the genus Rudbeckia.

Sources: The World Checklist of Vascular Plants (WCVP)

Distribution

This plant is widely distributed across various regions of the European continent. In Northern Europe, its presence is noted in Great Britain and Ireland. It can also be found extending further north into Norway and Sweden. Additionally, the species is located within Middle Europe, specifically in Austria. These locations demonstrate the plant's ability to thrive in diverse European climates.

Sources: The World Checklist of Vascular Plants (WCVP)

Botanical Identification

Ecology

The ecology of Rudbeckia hirta is characterized by its ability to thrive in disturbed and open landscapes, frequently colonizing anthropogenically altered environments such as crop fields and old fields. As a pioneer species, it excels in high-light environments where competition from dense forest canopies is minimal, allowing it to establish itself in nutrient-variable soils common to agricultural margins and abandoned grasslands. Its presence in these transitional habitats indicates a high tolerance for seasonal fluctuations in moisture and soil disturbance, making it a resilient component of early-successional ecosystems. By occupying these open niches, the species plays a vital role in stabilizing soil and providing resources within the ecological framework of disturbed meadowlands.

Habitat :

crop fields, old fields

Life history

The life history of Rudbeckia hirta is characterized by its status as an annual plant, completing its entire developmental cycle from germination to seed production within a single growing season. Functioning as a therophyte, the plant survives unfavorable periods through the production of seeds rather than persistent above-ground structures. This lifecycle is marked by a deciduous nature, where the aerial parts of the plant perish at the end of the season, leaving only the seeds to await more favorable conditions. As a therophyte, its biological strategy focuses on rapid growth and efficient reproductive output to ensure the continuation of the species before the onset of environmental stressors.

Deciduousness :

deciduous

Life form :

therophyte

Lifecycle :

annual

Morphology

The morphology of Rudbeckia hirta is characterized by its growth form as a non-woody herb and forb. As a terrestrial species, it does not function as an epiphyte or an aquatic plant, and it operates as an independent organism rather than a parasite. The plant is self-supporting in its structure, lacking any climbing or vine-like tendencies. Its shoots exhibit an erect orientation, supporting a stature that typically reaches a mean height of 0.25 m, though individual plants can vary significantly in size, ranging from a minimum height of 0.1 m to a maximum height of 1.2 m.

Aquatic :

terrestrial

Climber :

self-supporting

Epiphyte :

terrestrial

Growth form :

herb

Growth form :

forb

Parasite :

independent

Plant height max:

1.2 m

Plant height mean:

0.25 m

Plant height min:

0.1 m

Shoot orientation :

erect

Woodiness :

non-woody

Physiology

The physiology of Rudbeckia hirta is characterized by a C3 photosynthetic pathway, which involves the direct fixation of atmospheric carbon dioxide via the Calvin cycle. As a non-carnivorous species, it relies on its root system and soil nutrient availability rather than the capture and digestion of insects for supplemental nitrogen. Furthermore, the plant exhibits a Specific Leaf Area (SLA) with a mean value of 193.5 cm²/g, reflecting its specific leaf morphological adaptations and resource allocation strategies regarding light interception and water-use efficiency.

Carnivory :

non-carnivorous

Photosynthetic pathway :

C3

Specific Leaf Area (SLA) mean:

193.5 cm²/g

Reproduction

The reproduction of Rudbeckia hirta is primarily a sexual process, as asexual reproduction is absent in this species. The flowering period is extensive, typically beginning in June and continuing through October. During this time, the plant utilizes a biotic pollination syndrome, specifically relying on insects to facilitate the transfer of pollen. Once pollination occurs, the plant is capable of self-fertilization. The resulting fruit is classified as an achene, which is an indehiscent type, meaning it does not split open at maturity to release its contents. The seeds produced are quite small, with a minimum mass of 0.00015 g, a maximum mass of 0.004 g, and an average mass of approximately 0.000831825 g. Regarding the movement of these seeds, the species exhibits an anthropochorous dispersal syndrome, suggesting that human activity plays a role in its spread.

Dehiscence :

indehiscent

Dispersal syndrome :

anthropochorous

Flowering time :

Jun

Flowering time :

Oct

Fruit type :

achene

Pollination syndrome :

insect

Pollination syndrome :

biotic

Reproduction asexual :

absent

Seed mass max:

0.004 g

Seed mass mean:

0.000831825 g

Seed mass min:

0.00015 g

Self fertilization :

present

Sources: Global Inventory of Floras and Traits (GIFT)

Plant Parts

Rudbeckia hirta has 1 reported plant parts identified across 1 scientific publications and several other databases that are studied for medicinal purposes. The most consistently reported plant part include flower.

Flower

1. Plants (Basel, Switzerland)

Chemicals

Rudbeckia hirta has 2 reported phytochemicals identified across 1 scientific publications and several other databases. The most consistently reported chemicals include Fatty acids, Flavonoids.

Fatty acids

1. Plants (Basel, Switzerland)

Flavonoids

1. Plants (Basel, Switzerland)

Activities

Rudbeckia hirta has 4 reported activities identified across 1 scientific publications and several other databases. The most consistently reported activities include Antioxidant, Antibacterial, Antifungal, Antimicrobial.

Antioxidant

1. Plants (Basel, Switzerland)
2. Natural product research

Antibacterial

1. Planta medica

Antifungal

1. Planta medica

Antimicrobial

1. Plants (Basel, Switzerland)

Conditions

Rudbeckia hirta has 1 reported investigations on conditions identified across 1 scientific publications and several other databases. The most consistently reported conditions include Gram-positive bacteria.

Gram-positive bacteria

1. Plants (Basel, Switzerland)

Preparations

Rudbeckia hirta has 1 reported preparations identified across 1 scientific publications and several other databases. The most consistently reported preparations include studied extract.

Studied extract

1. Plants (Basel, Switzerland)