<i>Helleborus </i>plant named ‘COSEH 6900’

Abstract

A new and distinct cultivar of Helleborus plant named COSEH 6900, characterized by its upright and mounded plant habit; moderately vigorous to vigorous growth habit; dark green-colored leaves; freely flowering habit; single light yellow green-colored flowers; and good garden performance.

Claims

1. A new and distinct Helleborus plant named COSEH 6900 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 (FIG. 1 of 2) is a side perspective view of a typical flowering plant of COSEH 6900 grown in a container.

(3) The photograph on the second sheet (FIG. 2 of 2) is a close-up view of a typical flower and leaves of COSEH 6900.

DETAILED BOTANICAL DESCRIPTION

(4) The aforementioned photographs and following observations, measurements and values describe plants grown during December in 17-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 5 C. to 12 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 X Helleborus x hybridus COSEH 6900. Parentage: Female, or seed, parent.Unnamed selection of Helleborus niger, not patented. Male, or pollen, parent.Unnamed selection of Helleborus x hybridus, not patented. Propagation: Type.In vitro axillary meristem culture. Time to initiate roots, winter.About 55 days at temperatures about 12 C. Time to produce a rooted young plant, winter.About 170 days 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.Low branching; sparse. Plant description: Plant and growth habit.Herbaceous perennial; upright and mounding plant habit with flowers held within and above the foliar plane; plant shape, roughly flattened globular; moderately vigorous to vigorous growth habit and moderate growth rate. Plant height, soil level to top of foliar plane.About 27 cm. Plant height, soil level to top of flowers.About 28.5 cm. Plant diameter (area of spread).About 36 cm. Leaf description: Arrangement.Leaves arranged in a basal rosette; leaves palmately compound with typically five leaflets per leaf. Leaf length.About 13.3 cm. Leaf width.About 14.2 cm. Leaflet length.About 9 cm. Leaflet width.About 5.7 cm. Leaf shape.Palmate; reniform in outline. Leaflet shape.Broadly elliptic to broadly ovate and obovate. Leaflet apex.Broadly acute. Leaflet base.Attenuate. Leaflet margin.Deeply serrate; slightly to moderately undulate. Leaflet texture and luster, upper surface.Smooth, glabrous; leathery; moderately glossy. Leaflet texture and luster, lower surface.Smooth, glabrous; leathery; slightly glossy. Leaflet venation pattern.Pinnate. Leaflet color.Developing leaflets, upper surface: Close to 137A and proximally, close to 183A. Developing leaflets, lower surface: Close to 138B and proximally, tinged with close to 183C. Fully developed leaflets, upper surface: Darker than between NN137A and 147A; venation, close to 144C. Fully developed leaflets, lower surface: Close to 147B; venation, close to 144B to 144C. Petioles.Length: About 13.7 cm. Diameter: About 6 mm to 7 mm. Strength: Strong. Texture and luster, upper and lower surfaces: Smooth, glabrous; slightly glossy. Color, upper and lower surfaces: Close to 144A and proximally, covered heavily with fine dots, close to 200A. Flower description: Flower shape and habit.Single rotate flowers; flowers moderately cupped; arranged solitary or in clusters with about two flowers each; moderately freely flowering habit with about 13 flowers developing per plant; flowers face mostly outwardly to slightly nodding. Fragrance.None detected. Natural flowering season.Plants begin flowering about ten months after planting; plants flower from the late autumn into the winter in Germany. Flower longevity on the plant.About three to four months; sepals persistent, other flower parts are not persistent. Flower buds.Length: About 2.8 cm. Diameter: About 1.5 cm. Shape: Ovate to narrowly ovate. Texture and luster: Smooth, glabrous; matte. Color: Close to 157A to 157B. Inflorescence height.About 8.9 cm. Inflorescence diameter.About 11.2 cm. Flower diameter.About 8.4 cm by 8.4 cm. Flower depth (height).About 3.8 cm. Petals.All petals are transformed into nectaries. Sepals.Quantity and arrangement: About five, arranged in a single whorl. Length: About 5.2 cm. Width: About 5.6 cm. Shape: Reniform to broadly ovate, moderately concave. Apex: Obtuse. Base: Truncate to rounded. Margin: Entire; moderately undulate. Texture and luster, upper and lower surfaces: Smooth, glabrous; matte. Color: When opening, upper and lower surfaces: Close to 155C and proximally, close to 145B; venation, similar to lamina color. Fully opened, upper and lower surfaces: Close to between 150D and 157D, distally, tinged with close to 145D to 145C and proximally, close to 145B; venation, similar to lamina color; with development, close to 145A to 145B and proximally, close to 145A. Flower bracts.Quantity per flower: Typically one or two. Length: About 7.7 cm. Width: About 5.4 cm. Shape: Broadly ovate. Apex: Broadly acute. Base: Cuneate. Margin: Finely serrate to serrate; not undulate. Color, upper surface: Close to NN137A; venation, similar to lamina. Color, lower surface: Close to 147B; venation, close to 145B. Peduncles.Length: About 19.1 cm. Diameter: About 1 cm. Aspect: About 15 from vertical. Strength: Strong. Texture and luster: Smooth, glabrous; slightly glossy. Color: Close to 144B to 144C; proximally, moderately to heavily covered with fine dots, close to 184A to 184B. Pedicels.Length: About 3.8 cm. Diameter: About 4 mm. Aspect: About 10 from peduncle axis. Strength: Moderately strong. Texture and luster: Smooth, glabrous; moderately glossy. Color: Close to 144B to 144C and heavily covered with fine dots, close to 184B and 184C. Reproductive organs.Stamens: Quantity per flower: About 120. Filament length: About 1.6 cm. Filament color: Close to 157D. Anther shape: Double and broadly reniform; basifixed. Anther size: About 2 mm by 2 mm. Anther color: Close to 150C. Pollen amount: Moderate. Pollen color: Close to 4D. Pistils: Quantity per flower: About four to seven. Pistil length: About 4 mm. Stigma diameter: About 0.3 mm. Stigma shape: Club-shaped. Stigma color: Close to 150D. Style length: About 3 mm. Style color: Close to 185C. Ovary color: Close to 145D. Nectaries (transformed petals): Quantity per flower: About 14. Length: About 1.2 cm. Diameter: About 6 mm. Shape: Tubular, flattened. Texture and luster, inner and outer surfaces: Smooth, glabrous; slightly glossy. Color, immature, inner and outer surfaces: Close to N144A and proximally, close to 144A. Color, mature, inner and outer surfaces: Close to N144A, distally, close to 151B and 151C and proximally, close to 146C; with development, close to N144A and distally, close to 153C and proximally, close to 153C. Seeds and fruits.To date, 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, high temperatures about 35 C. and to be suitable for USDA Hardiness Zones 5 through 9. Pathogen & pest resistance: To date, plants of the new Helleborus have not been observed to be resistant to pathogens and pests common to Helleborus plants.