Helleborus 'COSEH 210’ Has Large White Flowers and Sells as 'HGC Joel'®

Summary: Helleborus ‘COSEH 210, ’ patented by German hellebore breeder Joseph Heuger, has large white flowers and sells under the trade name of ‘HGC Joel’®.

Helleborus 'COSEH 210' image included in patent application filed Jan. 7, 2009, with United States Patent and Trademark Office: Josef Heuger, Public Domain, via U.S. Patent and Trademark Office

Helleborus ‘COSEH 210,’ a Helleborus niger cultivar patented by German hellebore hybridizer Joseph Heuger, has large white flowers and sells under the trade name of ‘HGC Joel’®.

Helleborus niger is known commonly as black hellebore and as Christmas rose. Although its flowers are reminiscent of wild roses (Rosa canina), Helleborus niger does not belong to the rose family, Rosaceae. The Christmas rose is an evergreen, flowering perennial in the buttercup family, Ranunculaceae.

On Jan. 7, 2009, Josef Heuger filed an application with the United States Patent and Trademark Office for a patent for his invention, Helleborus ‘COSEH 210.’ June Hwu was the application’s primary examiner. On June 1, 2010, the U.S. Patent and Trademark Office assigned plant patent 21,048 to Helleborus ‘COSEH 210.’

Helleborus ‘COSEH 210’ has its origins in a cross-pollination program conducted in December 2002 by the inventor in a controlled greenhouse environment at his family’s nursery, Heuger Gartenbaubetriebe, in Glandorf, Lower Saxony state, northwestern Germany. Parent plants are two unnamed, unpatented proprietary Helleborus niger seedlings.

Heuger discovered and selected the new, single-flowering hellebore cultivar from among the seedlings’ progeny in November 2004. Propagation by division, conducted since February 2005, affirmed the retention and true reproduction of the new cultivar’s distinctive features.

Josef Heuger’s patent application for Helleborus ‘COSEH 210’ describes plants grown outdoors, in 13-centimeter (5.11-inch) containers, during winter. Production day temperatures spanned 5 to 32 degrees Celsius (41 to 89.6 degrees Fahrenheit). The night temperature range during production was from 1 degree to 25 degrees C (33.8 to 77 degrees F).

Production time for producing a young, rooted hellebore required about five months. Rooting temperatures ranged from 4 to 15 degrees C (39.2 to 59 degrees F).

Helleborus ‘COSEH 210’ has a sparse rooting habit. Fleshy roots are thick to thin. Coloring is white to brown.

An upright, mounded shape features early and uniform free flowering. The herbaceous perennial measures heights of about 15 to 20 centimeters (5.9 to 7.87 inches). Spread, or width, ranges from 30 to 35 centimeters (11.81 to 13.77 inches).

Each palmately compound leaf has five to seven leaflets that radiate outward from the leaf’s distal end, the point of attachment with the petiole, the stalk joining leaf to stem. Leaflets are roughly ovate, or egg-shaped, with serrated margins.

Leaflet length measures about 4 to 8 centimeters (1.57 to 3.14 inches). Width ranges from about 1.5 to 4 centimeters (0.59 to 1.57 inches).

Leaflets’ upper and lower surfaces have leathery textures. The smooth surfaces, lacking down or hair, are glabrous.

Upper surfaces of fully developed leaves are dark green (Royal Horticultural Society color chart color 147A). Lower surfaces are brown green (RHS 147B).

Leaflet venation pattern is pinnate (Latin: pinna, “feather”), with smaller, parallel veins branching off a main vein. Veins also form a network-style structure, described as a reticulate (Latin: reticulatus, “net-like”) arrangement.

Vein color of upper surfaces is brown green (RHS 146B). Lower surfaces have brown green (RHS 146D) venation.

The natural flowering season for Helleborus ‘COSEH 210’ is early and long. In Germany,  Helleborus ‘COSEH 210’ flowers from mid-November to February. The cultivar’s persistent flowers have a longevity of about three weeks.

The freely flowering habit of Helleborus ‘COSEH 210’ yields about 30 to 40 developing flowers per plant. The cultivar’s moderately fragrant aroma is pleasant.

Flowers measure a diameter of about 8 to 9 centimeters (3.14 to 3.54 inches). Their depth, or height, is about 2 centimeters (0.78 inches).

Floral arrangement is five sepals in a single whorl. Petals are not observed.

Sepal shape is broadly ovate, or egg-shaped. Sepal apex, or tip, is rounded. Margins are entire, with smooth, untoothed edges.

Upper and lower surfaces of sepals have a satiny texture. The smooth texture is glabrous, with an absence of down or hair.

Sepal length is about 4 to 4.5 centimeters (1.57 to 1.77 inches). Width is about 3 to 4 centimeters (1.18 to 1.57 inches).

Upper surfaces of opening and fully opened sepals are white (RHS NN155D). With development, upper surfaces have light green coloring (RHS 145C to 145A). Basal spot coloring is dark green to light green (RHS 144A to 144B).

Lower surfaces of opening and fully opened sepals are close to white (RHS NN155D). Basal spot coloring is light green (RHS 144B).

The patent application for Helleborus ‘COSEH 210’ notes the cultivar’s good garden performance. Helleborus ‘COSEH 210’ is weather-tolerant. The new cultivar tolerates rain and wind. It withstands a temperature range of about minus 10 degrees C (14 degrees F) to about 36 degrees C (96.8 degrees F).

Helleborus ‘COSEH 210’ sells under the trade name of ‘HGC Joel’®. The Helleborus Gold Collection (HGC®) is a symbol of quality, denoting winter-hardy hellebores with a beautiful, long blooming season.

The 2015-2016 Heuger Helleborus catalog sells ‘HGC Joel’℗ in pots sized 13 to 17 centimeters (5.11 to 6.69 inches). The winter bloomer’s growth is described as of medium vigor. Heating should start in mid-November. Maximum heating temperature is 14 degrees Celsius (57.2 degrees Fahrenheit). Selling is targeted for beginning at the end of November.

The takeaway for Helleborus ‘COSEH 210,’ with large white flowers and dark green leaves, is its reliable performance as a winter-blooming perennial and its commercial availability, with membership in the prestigious Helleborus Gold Collection (HGC®), as hellebore ‘HGC Joel’®.

Helleborus 'COSEH 210' sells under trade name of Helleborus 'Joel ’®: Rondom Klok Eelde @RondomKlokEelde, via Twitter Dec. 8, 2014

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Helleborus 'Coseh 210' image included in patent application filed Jan. 7, 2009, with United States Patent and Trademark Office: Josef Heuger, Public Domain, via U.S. Patent and Trademark Office @ http://pdfpiw.uspto.gov/.piw?PageNum=0&docid=PP021048;
via Plant Patents Image Database, Digital Collections @ University of Maryland Libraries @ https://digital.lib.umd.edu/plantpatents/id/PP21048

Helleborus 'COSEH 210' sells under trade name of Helleborus 'Joel ’®: Rondom Klok Eelde @ RondomKlokEelde, via Twitter Dec. 7, 2014, @ https://twitter.com/RondomKlokEelde/status/541837515611963392

For further information:

Burrell, C. Colston; Judith Knott Tyler. Hellebores: A Comprehensive Guide. Portland OR: Timber Press, 2006.

"Hellebore (Helleborus Gold Collection® Joel) (aka Coseh 210)." The National Gardening Association > Plants Database.
Available @ http://garden.org/plants/view/236698/Hellebore-Helleborus-Gold-Collection-Joel/

"Helleborus Plant Named 'Coseh 210.'" United States Patent and Trademark Office > Program in Word (PIW). June 1, 2010.
Available @ http://pdfpiw.uspto.gov/.piw?PageNum=0&docid=PP021048

"Helleborus Plant Named 'JGC Josef Lemper." United States Patent and Trademark Office > Program in Word (PIW). March 1, 2005.
Available @ http://pdfpiw.uspto.gov/.piw?PageNum=0&docid=PP015615

"HGC℗ Joel." Heuger > Katalog Helleborus 2015-2016.
Available @ http://www.heuger.com/fileadmin/lookbook/page4.html#/18

International Union for the Protection of New Varieties of Plants. “Document TGP/14: Glossary of Technical, Botanical and Statistical Terms Used in UPOV Documents.”  UPOV (Union Internationale Pour la Protection des Obtentions Végétales). Dec. 9, 2006.
Available @ http://www.upov.org/edocs/mdocs/upov/en/tc_edc/2007/tgp_14_draft_1_section_2_3_2.pdf

Marriner, Derdriu. "Helleborus 'COSEH 710' Has Light Green Flowers With Reddish Pink Overtones." Earth and Space News. Sunday, Nov. 13, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/11/helleborus-coseh-710-has-light-green.html

Marriner, Derdriu. "A Helleborus Plant Named 'COSEH 700' Has Large Light Green Flowers." Earth and Space News. Saturday, Nov. 12, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/11/a-helleborus-plant-named-coseh-700-has.html

Marriner, Derdriu. "A Helleborus Plant Named 'HGC Jacob' Has White to Light Green Flowers." Earth and Space News. Sunday, Nov. 6, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/11/a-helleborus-plant-named-hgc-jacob-has.html

Martin Ogden @Martin_Ogden. "Hellebore Gold Collection Joel begins flowering in November, with large flowers on a compact plant (18 sleeps now . .)." Twitter. Dec. 7, 2015.
Available @ https://twitter.com/Martin_Ogden/status/673943444067340289

Rondom Klok Eelde @ RondomKlokEelde. "Zware Helleborus Joel  van Kwekerij Paul Cox." Twitter. Dec. 7, 2014.
Available @ https://twitter.com/RondomKlokEelde/status/541837515611963392

"Types of Leaf Forms." Boundless > Biology > Textbooks > Boundless Biology > Plant Form and Physiology > Leaves. May 26, 2016.
Available @ https://www.boundless.com/biology/textbooks/boundless-biology-textbook/plant-form-and-physiology-30/leaves-181/types-of-leaf-forms-692-11918/