Rudbeckia

Rudbeckia triloba

The Rudbeckia (Rudbeckia ) are a genus of flowering plants in the sunflower family ( Asteraceae). The 20 to 23 species are distributed in North America. There are some varieties that are used as ornamental plants in parks and gardens.

Description

Rudbeckia species are one-, two-year or perennial herbaceous plants, mostly achieve the stature heights between 50 and 300 cm. Often they form rhizomes, stolons sometimes. The upright stems are often branched and are smooth or hairy. The stalked or sessile leaves are arranged opposite one another in basal rosettes and along the stem. The leaf blades are simple to pinnately lobed. The leaf margins are smooth, toothed or serrated.

Individually or several together in a schirmtraubigen total inflorescence are the bloom conditions. The basket bottom is domed cone- shaped, which in conjunction with the usually somewhat drooping ray florets results in the form of a hat and has led to the common name coneflower. However, you should not be confused with sun hats (Echinacea ). 5-20 bracts are arranged in mostly one to two, rarely three rows. There are chaff leaves present. In the flower basket are often tongue-shaped rim, zygomorphe, dreizipfelige ray florets ( ray florets ), radiärsymmetrische tubular flowers ( disc florets ) are always present. The five petals are fused into a tube.

The mostly black achenes are square and have a small pappus or he is missing.

Systematics and distribution

The genus name honors the Rudbeckia Swedish scientist Olof Rudbeck the Elder. The North American genus Rudbeckia belongs to the tribe Heliantheae in the subfamily herbaceous within the sunflower family ( Asteraceae).

The genus Rudbeckia is divided into three sections and contains about 20 to 23 species:

  • Section Dracopis ( Cass. ) A. Gray: The only kind: Rudbeckia amplexicaulis Vahl: It is an annual species, which is native to the central and eastern United States.
  • Rudbeckia alpicola Piper: It only grows at altitudes between 200 and 1500 meters in Washington.
  • Rudbeckia auriculata ( Perdue ) Kral: Grows at altitudes between 10 and 90 meters in Alabama, Florida and Georgia.
  • Rudbeckia californica A. Gray: Grows in the central Sierra Nevada.
  • Rudbeckia glaucescens Eastwood: Grows often on soils over serpentine. Darlingtonia.
  • Rudbeckia klamathensis PBCox & Urbatsch: Comes in altitude 1000-1600 meters in California.
  • Schlitzblättriger coneflower ( Rudbeckia laciniata L.), " Roeder Flower": With five varieties widely used in North America.
  • Rudbeckia maxima Nuttall: It grows only at altitudes 10-70 meters.
  • Rudbeckia mohrii A.Gray: Grows in moist palm savannas ( " Wet pine savannas " ) at altitudes between 0 and 50 meters in Florida and Georgia.
  • Rudbeckia montana A.Gray: Grows at altitudes 2400-2800 meters in Colorado and Utah.
  • Rudbeckia nitida Nuttall: Grows in " Wet pinelands " at altitudes between 0 and 40 meters in Florida and Georgia.
  • Rudbeckia occidentalis Nuttall: It grows at altitudes 1000-2800 meters.
  • Rudbeckia scabrifolia LeBrown: This endangered species is native only in the western Louisiana and eastern Texas.
  • Rudbeckia texana ( Perdue ) PBCox & Urbatsch: it is only in the western Louisiana and eastern Texas located at altitudes between 0 and 50 meters.
  • Shining Coneflower (Rudbeckia fulgida Aiton ): It is distributed with seven varieties in eastern North America.
  • Rudbeckia graminifolia ( Torrey & A. Gray ) CLBoynton & Beadle: Only in Florida at altitudes between 0 and 30 meters.
  • Rudbeckia grandiflora ( Sweet) CCGmelin ex DC. It is equipped with two varieties in North America, but not in the western area, distributed.
  • Rudbeckia heliopsidis Torrey & A. Gray: At altitudes between 70 and 200 meters.
  • Black- Eyed Susan (Rudbeckia hirta L.): It is distributed with four varieties in eastern North America.
  • Rudbeckia missouriensis Engelmann ex CLBoynton & Beadle: On dry stony plains and limestone at altitudes between 10 and 80 meters.
  • Weichhaarige Black-Eyed Susan (Rudbeckia mollis Elliott ): On dry sandy soils at altitudes between 30 and 90 meters.
  • Rudbeckia subtomentosa Pursh
  • Rudbeckia triloba L.: It is distributed with three varieties in eastern North America.

Use

From at least three species varieties are used as ornamental plants in parks and gardens of the temperate zones.

Varieties of the Shining Sun or Yellow coneflower ( Rudbeckia fulgida ):

Rudbeckia fulgida 'Ruby Star '

Rudbeckia fulgida var sullivantii ' Goldsteinii '

Rudbeckia fulgida var sullivantii ' Goldsteinii '

Rudbeckia fulgida var sullivantii ' Goldsteinii '

Schlitzblättriger coneflower ( Rudbeckia laciniata ):

Black- Eyed Susan (Rudbeckia hirta ):

Swell

  • Theodore M. Barkley, Luc Brouillet & John L. Strother: Tribe Heliantheae, In: Flora of North America Editorial Committee ( eds.): Flora of North America North of Mexico, Volume 21 - Magnoliophyta: unranked ( in part): Asteraceae, part 3, Oxford University Press, New York and Oxford, 2006, ISBN 0-19-530565-5: Lowell E. Urbatsch & Patricia B. Cox. in the Flora of North America; Volume 21: Rudbeckia, pp. 24 - Registered as text printed work. (Sections Description and systematics)
Asteroideae Pappus (flower structure) Washington (state) Georgia (U.S. state) Serpentinite
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