A new and distinct cultivar of Helleborus plant named ‘COSEH 4100’, characterized by its upright and mounding plant habit; uniform and freely flowering habit; dark green-colored leaves; freely and early flowering habit; single red purple to grayed purple-colored flowers; and good garden performance.

CROSS-REFERENCED TO CLOSELY-RELATED APPLICATIONS

Filed: Concurrently with this application having application Ser. No. 14/999,210

Filed: Concurrently with this application having application Ser. No. 14/999,211

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofHelleborusplant, botanically known asHelleborus×ericsmithii×Helleborus×hybridusand hereinafter referred to by the name ‘COSEH 4100’.

The newHelleborusplant is a product of a planned breeding program conducted by the Inventor in Glandorf, Germany. The objective of the breeding program was to create new uniformHelleborusplants with unique and attractive plant habit, leaf and flower coloration and resistance to pests common toHelleborusplants.

The newHelleborusplant originated from a cross-pollination conducted by the Inventor in Glandorf, Germany in February, 2011 of a proprietary selection ofHelleborus×ericsmithiiidentified as code number HE 10843, not patented, as the female, or seed, parent with an unnamed seedling selection ofHelleborus×hybridus, not patented, as the male, or pollen, parent. The newHelleborusplant was discovered and selected by the Inventor as a single flowering plant from within the progeny of the stated cross-pollination grown in a controlled greenhouse environment in Glandorf, Germany in November, 2012.

Asexual reproduction of the newHelleborusplant by divisions in a controlled environment in Glandorf, Germany since April, 2013 has shown that the unique features of this newHelleborusplant are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the newHelleborushave not been observed under all possible combinations of environmental conditions and cultural practices. The phenotype may vary somewhat with variations in environmental conditions such as temperature and light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘COSEH 4100’. These characteristics in combination distinguish ‘COSEH 4100’ as a new and distinctHelleborusplant:1. Upright and mounding plant habit.2. Uniform and freely flowering habit.3. Dark green-colored leaves.4. Freely and early flowering habit.5. Single red purple to grayed purple-colored flowers.6. Good garden performance.

Compared to plants of the female parent selection, plants of the newHelleborusand the female parent selection differ primarily in flower color as plants of the female parent selection have creamy white to pink-colored flowers. Compared to plants of the male parent selection, plants of the newHelleborusare more uniform and are more freely flowering.

Plants of the newHelleboruscan be compared to plants ofHelleborus×ericsmithii×Helleborus×hybridus‘COSEH 4200’, disclosed in a U.S. Plant Patent application filed concurrently having application Ser. No. 14/999,210, andHelleborus×ericsmithii×Helleborus×hybridus‘COSEH 4500’, disclosed in a U.S. Plant Patent application filed concurrently having application Ser. No. 14/999,211. Plants of the newHelleborusdiffer primarily from plants of ‘COSEH 4200’ and ‘COSEH 4500’ in flower color as plants of ‘COSEH 4200’ have pink-colored flowers and plants of ‘COSEH 4500’ have white-colored flowers.

Plants of the newHelleboruscan also be compared to plants ofHelleborus niger‘COSEH 700’, disclosed in U.S. Plant Pat. No. 21,003. In side-by-side comparisons, plants of the newHelleborusdiffer primarily from plants of ‘COSEH 700’ in flower color as plants of ‘COSEH 700’ have light green-colored flowers tinged with reddish overtones.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations, measurements and values describe plants grown during the autumn and winter in 13-cm containers in a glass-covered greenhouse in Glandorf, Germany and under cultural practices typical of commercialHelleborusproduction. During the production of the plants, day temperatures ranged from 12° C. to 32° C. and night temperatures ranged from 3° C. to 18° C. Plants were 16 months old when the photographs and the description were taken. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2015 Edition, except where general terms of ordinary dictionary significance are used.Botanical classification:Helleborus×ericsmithii×Helleborus×hybridus‘COSEH 4100’.Parentage:Female, or seed, parent.—Proprietary selection ofHelleborus×ericsmithiiidentified as code number HE 10843, not patented.Male, or pollen, parent.—Unnamed seedling selection ofHelleborus×hybridus, not patented.Propagation:Type.—By tissue culture.Time to initiate roots, winter.—About two months at temperatures about 12° C.Time to produce a rooted young plant, winter.—About six months at temperatures ranging from 4° C. to 15° C.Root description.—Thick to thin, fleshy; typically white to brown in color, actual color of the roots is dependent on substrate composition, water quality, fertilizer type and formulation, substrate temperature and physiological age of roots.Rooting habit.—Sparse.Plant description:Plant and growth habit.—Herbaceous perennial; upright and mounding plant habit with flowers held above the foliar plane; plant shape, roughly flattened globular; moderately vigorous growth habit; moderate growth rate.Plant height, soil level to top of foliar plane.—About 20.3 cm.Plant height, soil level to top of flowers.—About 41.1 cm.Plant diameter(area of spread).—About 47.5 cm.Leaf description:Arrangement.—Leaves arranged in a basal rosette; leaves palmately compound with typically five, or occasionally seven, leaflets per leaf.Leaf length.—About 24.1 cm.Leaf width.—About 28.9 cm.Leaflet length.—About 15.1 cm.Leaflet width.—About 7 cm.Leaf shape.—Palmate; reniform in outline.Leaflet shape.—Ovate, elliptic and obovate.Leaflet apex.—Acute.Leaflet base.—Attenuate.Leaflet margin.—Serrate; slightly to moderately undulate.Leaflet texture and luster, upper surface.—Smooth, glabrous; slightly rugose; leathery; glossy.Leaflet texture and luster, lower surface.—Smooth, glabrous; slightly rugose; leathery; moderately glossy.Leaflet venation pattern.—Pinnate.Leaflet color.—Developing leaflets, upper surface: Close to 137A. Developing leaflets, lower surface: Close to 147A tinged with close to N186C. Fully developed leaflets, upper surface: Close to darker than between 147A and N189A; venation, close to 143A. Fully developed leaflets, lower surface: Close to 147B tinged with close to N186C; venation, close to between N186C and 200B.Petioles.—Length: About 14.3 cm. Diameter: About 7.5 mm. Strength: Strong. Texture and luster, upper and lower surfaces: Smooth, glabrous; moderately glossy. Color, upper surface: Close to 146B, heavily speckled and tinged with close to between 177A and 200C. Color, lower surface: Close to between 177A and 200C, speckled and tinged with close to 146B.Flower description:Flower shape and habit.—Single rotate flowers arranged solitary or in panicles; freely and uniform flowering habit with about five flowers per inflorescence and about 48 flowers developing per plant; flowers facing slightly upright, outwardly to slightly nodding.Fragrance.—None detected.Natural flowering season.—Plants begin flowering about ten months after planting; plants flower during the winter in Germany.Flower longevity on the plant.—About ten days; flowers not persistent.Flower buds.—Length: About 2 cm. Diameter: About 1.2 cm. Shape: Ovate. Texture and luster: Glabrous; matte. Color: Close to between N77B and 185C; towards the base, close to 145B to 145C.Inflorescence height.—About 36.3 cm.Inflorescence diameter.—About 22.3 cm.Flower diameter.—About 8.4 cm.Flower depth(height).—About 2.5 cm.Petals.—Transformed into nectaries.Sepals.—Quantity and arrangement: About five, arranged in a single whorl. Length: About 4.2 cm. Width: About 3.6 cm. Shape: Broadly ovate. Apex: Obtuse. Base: Cuneate. Margin: Entire. Texture and luster, upper and lower surfaces: Glabrous; matte. Color: When opening, upper surface: Close to between 76D and 186D, heavily speckled and flushed with close to between 185C and 186A. When opening, lower surface: Close to 186A to 186C; venation, close to 60C. Fully opened, upper surface: Close to between 61A and N186D, heavily speckled and flushed with close to 186C and 186D. When opening, lower surface: Close to 186B; flushed with close to between 64A and Ni 86D; venation, close to between 64A and N186D.Flower bracts.—Quantity per flower: Typically one. Length: About 4.9 cm. Width: About 3 cm. Shape: Ovate. Apex: Acute. Base: Broadly cuneate. Margin: Entire; distally, occasionally serrated; slightly undulate. Color, upper surface: Close to NN137A. Color, lower surface: Close to 147B, tinged with close to N186C; venation, close to between N186C and 200C.Peduncles.—Length: About 26.4 cm. Diameter: About 9 mm. Aspect: About 15° from vertical. Strength: Strong. Texture and luster: Glabrous; moderately glossy. Color: Close to 146D, densely speckled and flushed with close to 176B to 176C.Pedicels.—Length: About 3 cm. Diameter: About 2.5 mm. Aspect: About 20° from peduncle axis. Strength: Moderately strong. Texture and luster: Glabrous; glossy. Color: Close to 182B.Reproductive organs.—Stamens: Quantity per flower: About 90. Filament length: About 1.6 cm. Filament color: Close to N155C. Anther shape: Reniform; basifixed. Anther size: About 1.75 mm by 2 mm. Anther color: Close to 150C. Pollen amount: Scarce. Pollen color: Close to 4D. Pistils: Quantity per flower: About five. Pistil length: About 1.4 cm. Stigma diameter: About 0.3 mm. Stigma shape. Club-shaped. Stigma color: Close to 155A. Style length: About 1.375 cm. Style color: Close to 187D. Ovary color: Close to 146D, heavily speckled and flushed with close to 183C. Nectaries (transformed petals): Quantity per flower: About 13 to 19. Length: About 1.2 cm. Diameter: About 3 mm. Shape: Tubular, flattened. Texture and luster, inner surface: Smooth, glabrous; matte. Texture and luster, outer surface: Smooth, glabrous; glossy. Color, immature, inner and outer surfaces: Close to 144B to 144C; towards the apex, close to 144C. Color, mature, inner and outer surfaces: Close to 144A to 144B; towards the apex, close to 151A to 151B.Seeds and fruits.—Seed and fruit development have not been observed on plants of the newHelleborus.Garden performance: Plants of the newHelleborushave been observed to have good garden performance and to tolerate rain, wind and to be suitable for USDA Hardiness Zones 5 through 9.Pathogen & pest resistance: Plants of the newHelleborushave not been observed to be resistant to pathogens and pests common toHelleborusplants.