Helleborus ‘Walhero’ Has Pink Flowers and Sells as 'Walberton’s® Rosemary'

Summary: Helleborus ‘Walhero,’ a hybrid hellebore species by British helleborist David Tristram, has pink flowers and sells as 'Walberton’s® Rosemary.'

overall view of 3-year-old Helleborus 'Walhero' plants in late spring; image included in David Tristram’s patent application, filed April 3, 2007, 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/19400/pp19439.pdf

Helleborus ‘Walhero,’ a hybrid hellebore species by British nursery owner and plant breeder David Tristram, has mid to dark pink flowers and sells as 'Walberton’s® Rosemary.'

On April 3, 2007, Tristram filed an application with the United States Patent and Trademark Office, for a patent for Helleborus ‘Walhero.’ Primary examiner Kent L. Bell and assistant examiner Georgia Helmer review Tristram’s application. On Nov. 11, 2008, the U.S. Patent and Trademark Office assigned plant patent number 19,439 to Helleborus ‘Walhero.’

‘Walhero’ resulted from a breeding program that Tristram established in 1980 in an unheated greenhouse at his business, Walberton Nursery, in south England’s West Sussex County. The program aimed at producing new, vigorous hellebores with attractively presented flowers.

The program yielded over two decades of raised and crossed promising seedlings. Selected seedlings of Helleborus orientalis, known popularly as Lenten rose, were crossed with Helleborus niger ‘Potter’s Wheel,’ a renowned, unpatented Christmas rose, or black hellebore, variety  discovered by David’s father, Major G.H. Tristram. Each year’s hybridized seedlings were raised to first or second year flowering. David Tristram then retained a select number for longer term evaluation.

In 2002, David Tristram selected ‘Walhero’ from among the program’s collection of promising seedlings. The inventor based his selection upon such distinctive features as crop uniformity; lengthy, prolific blooming of large, well-presented, saucer-shaped, pink flowers; upright, vigorous growth. Propagation by tissue culture, which began in 2003, demonstrated the retention and true reproduction of the compact, upright perennial’s distinctive traits over successive generations.

Tristram’s patent application describes 2-year-old plants grown outdoors in West Sussex County in 3-liter (0.79-gallon) containers. Soil preference is deep, fertile and rich with humus.

Sunlight requirements call for moderate, light or filtered shade.

A 2-year-old 'Walhero' plant measures a height of 35 centimeters (13.77 inches). Spread, or width, reaches 50 centimeters (19.68 inches).

‘Walhero’ is an acaulescent (Latin: ab, “away from” + caulis, “stalk”) evergreen. Its flower and leaf stems arise basally.

Leaves comprise three to nine leaflets. Leaflets range in length from 7 to 13 centimeters (2.75 to 5.11 inches) and in width from 2 to 5 centimeters (0.78 to 1.96 inches).

Leaflet shape is elliptical to lanceolate, or lance-shaped. Margins are serrated. Smooth, non-downy leaflets’ texture is described as glabrous with a semi-glossy appearance.

Adaxial, or upper, surfaces of leaflets display brown green (Royal Horticultural Society colour chart color 189A) and brown green (RHS 191A) as individual colors. Abaxial, or lower, surfaces display brown green (RHS 191A) and brown green (RHS 191B) as individual colors.

‘Walhero’ displays a pinnate vein pattern. Parallel, smaller veins branch from each leaflet’s main vein. Coloring is brown green (RHS 191A) on upper surfaces and brown green (RHS 191B) on lower surfaces.

Nut-shaped flower buds are 1.5 centimeters (inches) in width and 3 centimeters (inches) in length. Brown purple (RHS 183C) and blue pink (RHS 186C) are present as individual colors on each bud.

Oval-shaped bracts, numbering one or two, subtend, or underlie, each flower bud. Bracts have widths of 1.5 to 2 centimeters (0.59 to 0.78 inches) and lengths of 2.5 to 4 centimeters (0.98 to 1.57 inches).

Bract surfaces, which are smooth and free from down or hair, are described as glabrous. Their smooth, untoothed margins are described as entire.

Upper surfaces of bracts are brown green (RHS 138B). Lower surfaces may display brown green (RHS 138A) and brown red (RHS 182C) as individual colors.

closeup of 'Walhero' flower and bud; image included in David Tristram’s patent application, filed April 3, 2007, 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/19400/pp19439.pdf

‘Walhero’ blooms lengthily and prolificially. Its flowering season extends from late December to March and April. ‘Walhero’ has no discernible fragrance.

Flowers retain their shapes for two months. Individuals last 15 days on the plant. Lastingness in fresh, cut arrangements is 10 days.

Spicate inflorescence features three or four flowers per spike. Stellate, or star-shaped, flowers have a horizontal, slightly nodding presentation.

Petals are only present as nectaries. Falloff occurs early.

Each flower consists of five unfused sepals. Sepal shape, described as saucer-like, is between ovate, or egg-shaped, and orbicular. Smooth, untoothed margins are described as entire. Slightly puberulent surfaces have minute, soft downy hairs.

Sepal length range of 4 to 4.5 centimeters (1.57 to 1.77 inches) increases to 4.5 to 5 centimeters (1.77 to 1.96 inches) with age. Width range of 3 to 3.5 centimeters (1.18 to 1.37 inches) increases to 4.5 to 5 centimeters (1.77 to 1.96 inches) with age.

Brown purple (RHS 183D), brown purple (RHS 186B), grey brown (RHS 199C) and white endure as individual colors on each sepal throughout the blooming season.

The takeaway for Helleborus ‘Walhero’ is the pink-flowered, winter-hardy hellebore’s floriferous longevity in indoor and outdoor niches under the trade name of 'Walberton’s® Rosemary.'

Helleborus Walberton’s® Rosemary, Royal Horticultural Society’s Wisley Garden, Surrey County, South East England, March 24, 2012: Leonora (Ellie) Enking, CC BY SA 2.0, via Flickr

Acknowledgment

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

Image credits:

3-year-old Helleborus 'Walhero' in late spring; image included in David Tristram’s patent application, filed April 3, 2007, 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/19400/pp19439.pdf

closeup of 'Walhero' flower and bud; image included in David Tristram’s patent application, filed April 3, 2007, 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/19400/pp19439.pdf

Helleborus Walberton’s® Rosemary, Royal Horticultural Society’s Wisley Garden, Surrey County, South East England, March 24, 2012: Leonora (Ellie) Enking, CC BY SA 2.0, via Flickr @ https://www.flickr.com/photos/33037982@N04/7012330033/

For further information:

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

“Helleborus Plant Named ‘Walhero.’” United States Patent and Trademark Office > Program in Word (PIW). Nov. 11, 2008.
Available @ http://pdfpiw.uspto.gov/.piw?PageNum=0&docid=PP019439

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

“Lenten Rose (Helleborus x hybridus Walberton’s® Rosemary).” The National Gardening Association > Plants Database > Hellebores.
Available @ http://garden.org/plants/view/533820/Lenten-Rose-Helleborus-x-hybridus-Walbertons-Rosemary/

Marriner, Derdriu. “Helleborus ‘Walhelivor’ Has Green- and Pink-Tinted Ivory White Flowers.” Earth and Space News. Sunday, Jan. 15, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/01/helleborus-walhelivor-has-green-and.html

“A ‘Potted’ History.” Walberton Nursery > History.
Available @ http://www.walberton-nursery.co.uk/history/

“PP19439 -- Helleborus Plant Named ‘Walhero.’” University of Maryland > Plant Patents Image Database.
Available @ http://www.lib.umd.edu/plantpatents/id/15404

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

“Walberton’s® Introductions.” Walberton Nursery.
Available @ http://www.walberton-nursery.co.uk/walbertons-introductions/