Helleborus plant named ‘COSEH 3090’

Abstract

A new and distinct cultivar of Helleborus plant named ‘COSEH 3090’, characterized by its upright and mounding plant habit; uniform and freely flowering habit; dark green-colored leaves; freely and early flowering habit; single white-colored flowers; and good garden performance.

Claims

1. A new and distinct Helleborus plant named ‘COSEH 3090’ as illustrated and described.

Description

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

(1) The accompanying colored photographs illustrate the overall appearance of the new Helleborus plant showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description which accurately describe the colors of the new Helleborus plant.

(2) The photograph on the first sheet is a side perspective view of a typical flowering plant of ‘COSEH 3090’ grown in a container.

(3) The photograph on the second sheet is a close-up view of a typical flower of ‘COSEH 3090’.

DETAILED BOTANICAL DESCRIPTION

(4) The aforementioned photographs and following observations, measurements and values describe plants grown during the autumn in 13-cm containers in a glass-covered greenhouse in Glandorf, Germany and under cultural practices typical of commercial Helleborus production. 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 14 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 niger ‘COSEH 3090’. Parentage: Female, or seed, parent.—Unnamed proprietary seedling selection of Helleborus niger, not patented. Male, or pollen, parent.—Unnamed proprietary seedling selection of Helleborus niger, 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; low vigor to moderately vigorous growth habit; slow to moderate growth rate. Plant height, soil level to top of foliar plane.—About 15.1 cm. Plant height, soil level to top of flowers.—About 28.2 cm. Plant diameter (area of spread).—About 30 cm. Leaf description: Arrangement.—Leaves arranged in a basal rosette; leaves palmately compound with typically seven leaflets per leaf. Leaf length.—About 11.4 cm. Leaf width.—About 12.1 cm. Leaflet length.—About 7.3 cm. Leaflet width.—About 3.5 cm. Leaf shape.—Palmate; reniform in outline. Leaflet shape.—Obovate. Leaflet apex.—Abruptly acute. Leaflet base.—Attenuate. Leaflet margin.—Serrate. Leaflet texture and luster, upper surface.—Smooth, glabrous; slightly rugose; glossy. Leaflet texture and luster, lower surface.—Smooth, glabrous; slightly rugose; slightly glossy. Leaflet venation pattern.—Pinnate. Leaflet color.—Developing leaflets, upper surface: Close to between NN137B and 147A. Developing leaflets, lower surface: Close to between 138A and 138B. Fully developed leaflets, upper surface: Close to darker than between NN137A and 147A; venation, close to 137B to 137C. Fully developed leaflets, lower surface: Close to 144A; venation, close to 144B. Petioles.—Length: About 8.9 cm. Diameter: About 6 mm. Strength: Strong. Texture and luster, upper and lower surfaces: Smooth, glabrous; slightly glossy. Color, upper and lower surfaces: Close to 144B heavily tinged and speckled with close to 177A. Flower description: Flower shape and habit.—Single rotate flowers arranged solitary or in pairs; freely and uniform flowering habit with about 22 flowers developing per plant; flowers facing outwardly to slightly nodding. Fragrance.—None detected. Natural flowering season.—Plants begin flowering about ten months after planting; plants flower from autumn into winter in Germany. Flower longevity on the plant.—About ten days; flowers not persistent. Flower buds.—Length: About 2.1 cm. Diameter: About 1.3 cm. Shape: Ovate. Texture and luster: Glabrous; matte. Color: Close to NN155D. Flower diameter.—About 7.4 cm. Flower depth (height).—About 2.3 cm. Petals.—Transformed into nectaries. Sepals.—Quantity and arrangement: Five, arranged in a single whorl. Length: About 3.7 cm. Width: About 3.1 cm. Shape: Broadly ovate. Apex: Obtuse. Base: Cuneate. Margin: Entire. Texture and luster, upper and lower surfaces: Glabrous; matte. Color: When opening, upper and lower surfaces: Close to NN155B. Fully opened, upper and lower surfaces: Close to NN155B; towards the base, close to 150D. Flower bracts.—Quantity per flower: Typically one. Length: About 3.3 cm. Width: About 2.6 cm. Shape: Ovate. Apex: Acute. Base: Broadly cuneate. Margin: Entire; slightly undulate. Color, upper surface: Close to 138A. Color, lower surface: Close to 138B. Peduncles.—Length: About 20.6 cm. Diameter: About 5 mm. Aspect: About 20° from vertical. Strength: Moderately strong. Texture and luster: Glabrous; slightly glossy. Color: Close to 144B to 144C, heavily tinged and speckled with close to 174A. Pedicels.—Length: About 9 cm. Diameter: About 3 mm. Aspect: About 25° from peduncle axis. Strength: Moderately strong. Texture and luster: Glabrous; glossy. Color: Close to 144B to 144C, heavily tinged and speckled with close to 174A. Reproductive organs.—Stamens: Quantity per flower: About 70. Filament length: About 1.3 cm. Filament color: Close to NN155D. Anther shape: Reniform; basifixed. Anther size: About 1.5 mm by 2 mm. Anther color: Close to 3C. Pollen amount: Moderate to abundant. Pollen color: Close to 2D. Pistils: Quantity per flower: About nine. Pistil length: About 1 cm. Stigma diameter: About 0.3 mm. Stigma shape: Club-shaped. Stigma color: Close to 148D. Style length: About 9.5 mm. Style color: Close to NN155A. Ovary color: Close to slightly lighter than 157D. Nectaries (transformed petals): Quantity per flower: About 20. Length: About 1 cm. Diameter: About 3.5 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 N144D; towards the apex, close to 1B. Color, mature, inner and outer surfaces: Close to 144B; towards the apex, close to 2D. Seeds and fruits.—Seed and fruit development have not been observed on plants of the new Helleborus. Garden performance: Plants of the new Helleborus have 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 new Helleborus have not been observed to be resistant to pathogens and pests common to Helleborus plants.