Helleborus ‘HGC Green Corsican’ Has White Flowers and Dark Green Leaves

Summary: Helleborus ‘HGC Green Corsican,’ a hybrid hellebore by German breeder Joseph Heuger, has white flowers and dark green leaves.

side view of flower of Helleborus ‘HGC Green Corsican’ in images included in Joseph Heuger’s patent application, filed June 28, 2004, with the United States Patent and Trademark Office (USPTO): color scans via Plant Patents Image Database, Engineering & Physical Science Library (USPTO designation: College Park Patent & Trademark Resource Center), University of Maryland, CC BY 2.0, via University of Maryland’s Plant Patents Image Database @ http://www.lib.umd.edu/plantpatents/binaries/15600/pp15641.pdf

Helleborus ‘HGC Green Corsican,’ a hybrid hellebore (Helleborus niger x Helleborus argutifolius) by German hellebore hybridizer Joseph Heuger, has white flowers and dark green leaves.

On June 28, 2004, Heuger filed an application with the United States Patent and Trademark Office for a patent for Helleborus ‘HGC Green Corsican.’ Primary examiner Kent Bell and assistant examiner Wendy C. Haas reviewed Heuger’s application. On March 8, 2005, the U.S. Patent and Trademark Office assigned plant patent number 15,641 to Helleborus ‘HGC Green Corsican.’

The new cultivar has its origins in a breeding program conducted by Heuger in January 1999. A cross-pollination of an unnamed, unpatented female Christmas rose, or black hellebore (Helleborus niger), seedling with an unnamed, unpatented male Corsican hellebore (Helleborus argutifolius) seedling took place at Heuger’s family nursery, Heuger Gartenbaubetriebe, in Glandorf, Lower Saxony state, northwestern Germany.

Heuger discovered and selected the flowering plant now known as Helleborus ‘HGC Green Corsican’ from among the cross-pollinated parents’ progeny. ‘HGC Green Corsican’ displayed distinctive traits of a good, compact and mounded habit; attractive flower and leaf colors; a lengthy flowering time. Propagation by divisions, begun in March 2001, revealed the retention and true reproduction of distinctive traits over successive generations.

Heuger’s patent application describes approximately 6-month-old plants that were grown during winter in 15-centimeter (5.9-inch) containers. During production, temperatures in the Heuger nursery’s glass-covered greenhouse registered about 18 degrees Celsius (64.4 degrees Fahrenheit) during the day and about 14 degrees C (57.2 degrees F) during the night.

Helleborus ‘HGC Green Corsican’ has a temperature tolerance ranging from minus 10 to 36 degrees C (14 to 96.8 degrees F).

‘HGC Green Corsican’ exhibits a moderately vigorous growth habit. Its compact, mounded habit includes basal leaves and single flowers. Its height measures about 25 centimeters (9.84 inches). Its spread, or width, reaches about 56 centimeters (22.04 inches).

Basal leaves are palmately compound. Three to five leaflets radiate from each leaf’s petiole, or leaf stalk. Leaflet length ranges from about 6 to 14 centimeters (2.36 to 5.51 inches). Leaflet width is from 3 to 7 centimeters (1.18 to 2.75 inches).

Lanceolate, or lance-shaped, leaves have serrated margins. Glabrously textured upper and lower surfaces are hairlessly smooth.

Upper surfaces of fully expanded leaflets are dark green (between Royal Horticultural Society colour chart colors 137A and 147A). Veins are brown green (RHS 146C).

Lower surfaces of fully expanded leaflets are close to brown green (RHS 146B). Venation is brown green (RHS 146C), with an overlay of brown purple (RHS 183A).

‘HGC Green Corsican’ has slightly fragrant flowers with a long natural blooming season. Intermittent flowering takes place from December to February in Glandorf. On the plant, flowers last about 15 days.

A freely flowering habit yields about 25 developing flowers per plant over the blooming period. Flowers, which have upright to outward faces, are borne as single arrangements on mostly upright cymes (Latin: cyma, “young cabbage sprout”). Terminal buds on lateral stems follow firstly developing, central-stemmed, single terminal flower.

Ovoid, or egg-shaped, buds have a height of about 2 centimeters (0.78 inches) and a diameter of about 1 centimeter (0.39 inches). Coloring is light green (RHS 145D).

Each flower typically has five sepals, arranged in a single whorl. Tiny petals form inconspicuous nectaries.

Sepal length is about 3.9 centimeters (1.53 inches). Sepal width is about 3.5 centimeters (1.37 inches).

Broadly ovate, or egg-shaped, sepals have smooth, untoothed margins, described as entire. Glabrously textured upper and lower surfaces are satiny and hairlessly smooth.

Upper and lower surfaces of fully expanded sepals are white (RHS 155A), with light green (RHS 145D) toward the base. With development, coloring approaches light green (RHS 145D).

Peduncles, or flower stems, are strong, with upright orientation. Peduncles measure lengths of 12 to 20 centimeters (4.72 to 7.87 inches). Diameters range from about 2 to 3 millimeters (0.078 to 0.118 inches). Their coloring is light green (RHS 145C), with an overlay of brown purple (RHS 184C).

Pedicels, or small floral stalks, connect flowers with peduncles. Pedicel lengths are about 2 to 5 centimeters (0.787 to 1.96 inches). Diameter range is 6 to 8 millimeters (0.23 to 0.31 inches). Pedicels are strong, with an outwardly angled orientation. Their glabrous texture is hairlessly smooth. Pedicel coloring is light green (RHS 144D).

The takeaway for Helleborus ‘HGC Green Corsican’ is its winter showiness, with white flowers in a dark green leafy frame that lengthily blooms from December to February.

closeup of Helleborus ‘HGC Green Corsican’ flower in images included in Joseph Heuger’s patent application, filed June 28, 2004, with the United States Patent and Trademark Office (USPTO): color scans via Plant Patents Image Database, Engineering & Physical Science Library (USPTO designation: College Park Patent & Trademark Resource Center), University of Maryland, CC BY 2.0, via University of Maryland’s Plant Patents Image Database @ http://www.lib.umd.edu/plantpatents/binaries/15600/pp15641.pdf

Acknowledgment

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

Image credits:

side view of flower of Helleborus ‘HGC Green Corsican’ in images included in Joseph Heuger’s patent application, filed June 28, 2004, with the United States Patent and Trademark Office (USPTO): color scans via Plant Patents Image Database, Engineering & Physical Science Library (USPTO designation: College Park Patent & Trademark Resource Center), University of Maryland, CC BY 2.0, via University of Maryland’s Plant Patents Image Database @ http://www.lib.umd.edu/plantpatents/binaries/15600/pp15641.pdf

closeup of Helleborus ‘HGC Green Corsican’ flower in images included in Joseph Heuger’s patent application, filed June 28, 2004, with the United States Patent and Trademark Office (USPTO): color scans via Plant Patents Image Database, Engineering & Physical Science Library (USPTO designation: College Park Patent & Trademark Resource Center), University of Maryland, CC BY 2.0, via University of Maryland’s Plant Patents Image Database @ http://www.lib.umd.edu/plantpatents/binaries/15600/pp15641.pdf

For further information:

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

Burrell, C. Colston; Judith Knott Tyler. “Not Your Mother’s Hellebores: A New Look at Species and Hybrids (Part 2).” Pacific Horticulture magazine. January 2008.
Available @ http://www.pacifichorticulture.org/articles/not-your-mothers-hellebores-part-2/

“Hellebore (Helleborus niger Gold Collection® Green Corsican).” The National Gardening Association > Plants Database > Hellebores.
Available @ http://garden.org/plants/view/236921/Hellebore-Helleborus-niger-Gold-Collection-Green-Corsican/

“Helleborus Plant Named ‘HGC Green Corsican.’” United States Patent and Trademark Office > Program in Word (PIW). March 8, 2005.
Available @ http://pdfpiw.uspto.gov/.piw?PageNum=0&docid=PP015641

“HGC Jericho’℗. Heuger > Katalog Helleborus 2015-2016.
Available @ http://www.heuger.com/fileadmin/lookbook/page1.html#/16

International Union for the Protection of New Varieties of Plants. “Document TGP/14: Glossary of Technical, Botanical and Statistical Terms Used in UPOV Documents. Section 2: Botanical Terms: Subsection 3: Color: (2): Color Names for the RHS Colour Chart.” UPOV (Union Internationale Pour la Protection des Obtentions Végétales). Dec. 9, 2006.
Available @ http://www.upov.int/edocs/mdocs/upov/en/tc_edc?2007/tgp_14_draft_1_section_2_3_2.pdf

Marriner, Derdriu. “Helleborus ‘COSEH 210’ Has Large White Flowers and Sells as ‘HGC Joel’®.” Earth and Space News. Sunday, Jan. 8, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/01/helleborus-coseh-210-has-large-white.html

Marriner, Derdriu. “Helleborus ‘COSEH 710’ Has Light Green Flowers With Reddish Pink Flushes.” 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. “Helleborus ‘COSEH 740’ Has White Flowers and Dark Green Leaves.” Earth and Space News. Saturday, Nov. 26, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/11/helleborus-coseh-740-has-white-flowers.html

Marriner, Derdriu. “Helleborus ‘HGC Double Surprise’ Has Purple-Spotted White Double Flowers.” Earth and Space News. Sunday, Jan. 22, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/01/helleborus-hgc-double-surprise-has.html

Marriner, Derdriu. “Helleborus ‘HGC Jericho’ Has Large White Flowers and Dark Green Leaves.” Earth and Space News. Sunday, Feb. 5, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/02/helleborus-hgc-jericho-has-large-white.html

Marriner, Derdriu. “Helleborus ‘HGC Josef Lemper’ Has White Flowers and Dark Green Leaves.” Earth and Space News. Saturday, Jan. 28, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/01/helleborus-hgc-josef-lemper-has-white.html

Marriner, Derdriu. “Helleborus ‘HGC Lady Freckle’ Has Red Purple-Spotted White Flowers.” Earth and Space News. Sunday, Jan. 29, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/01/helleborus-hgc-lady-freckle-has-red.html

Marriner, Derdriu. “Helleborus ‘HGC Silvermoon' Has White to Light Green Flowers.” Earth and Space News. Saturday, Feb. 4, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/02/helleborus-hgc-silvermoon-has-white-to.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

“PP15641 -- Helleborus Plant Named ‘HGC Green Corsican.’” University of Maryland > Plant Patents Image Database.
Available @ http://www.lib.umd.edu/plantpatents/id/11606

Rice, Graham; Elizabeth Strangman. The Gardener’s Guide to Growing Hellebores. Newton Abbot, England: David and Charles, 2005.