Patent Publication Number: US-PP32239-P2

Title: Hydrangea plant named ‘H218912’

Description:
Botanical designation:  Hydrangea macrophylla.    
     Cultivar denomination: ‘H218912’. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a new and distinct cultivar of  Hydrangea  plant, botanically known as  Hydrangea macrophylla , commercially referred to as a mophead-type  Hydrangea  and hereinafter referred to by the name ‘H218912’. 
     The new  Hydrangea  plant is a product of a planned breeding program conducted by the Inventor in De Kwakel, The Netherlands and Lengerich, Germany. The objective of the breeding program was to create new strong and freely-branching  Hydrangea  plants with strong sturdy stems, uniform flowering habit, large inflorescences with numerous showy sterile flowers, attractive sterile flower color and good postproduction longevity. 
     The new  Hydrangea  plant originated from a cross-pollination made by the Inventor in March, 2013 in De Kwakel, The Netherlands, of a proprietary selection of  Hydrangea macrophylla  identified as code number 05-0126-008, not patented, as the female, or seed, parent with  Hydrangea macrophylla  ‘Green Shadow’, not patented, as the male, or pollen, parent. The new  Hydrangea  plant was discovered and selected by the Inventor as a single flowering plant from within the progeny of the stated cross-pollination in a controlled greenhouse environment in Lengerich, Germany in March, 2014. 
     Asexual reproduction of the new  Hydrangea  plant by vegetative tip cuttings in a controlled environment in De Kwakel, The Netherlands since April, 2015 has shown that the unique features of this new  Hydrangea  plant are stable and reproduced true to type in successive generations. 
     SUMMARY OF THE INVENTION 
     Plants of the new  Hydrangea  have 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 ‘H218912’. These characteristics in combination distinguish ‘H218912’ as a new and distinct  Hydrangea  plant:
         1. Upright and uniformly mounded plant habit.   2. Vigorous growth habit and rapid growth rate.   3. Freely branching habit with strong, thick and sturdy stems.   4. Freely and uniformly flowering habit.   5. Mophead-type inflorescences with numerous red purple and yellow green-colored sterile flowers.   6. Good postproduction longevity.       

     Plants of the new  Hydrangea  can be compared to plants of the female parent selection. Plants of the new  Hydrangea  differ primarily from plants of the female parent selection in sterile flower color as plants of the new  Hydrangea  have red purple and yellow green-colored sterile flowers whereas plants of the female parent selection have dark red-colored sterile flowers. 
     Plants of the new  Hydrangea  can be compared to plants of the male parent selection. Plants of the new  Hydrangea  differ primarily from plants of the male parent selection in growth habit as plants of the new  Hydrangea  are more compact than plants of the male parent selection. 
     Plants of the new  Hydrangea  can be compared to plants of the  Hydrangea macrophylla  ‘HBA215910’, disclosed in U.S. Plant Pat. No. 29,171. In side-by-side comparisons, plants of the new  Hydrangea  differ primarily from plants of ‘HBA215910’ in the following characteristics:
         1. Plants of the new  Hydrangea  are broader and more vigorous than plants of ‘HBA215910’.   2. Plants of the new  Hydrangea  have longer leaves than plants of ‘HBA215910’.   3. Plants of the new  Hydrangea  have larger panicles than plants of ‘HBA215910’.   4. Plants of the new  Hydrangea  have larger sterile flowers than plants of ‘HBA215910’.   5. Plants of the new  Hydrangea  have red purple and yellow green-colored sterile flowers whereas plants of ‘HBA215910’ have dark red purple-colored sterile flowers with green-colored sectors.   6. Plants of the new  Hydrangea  and ‘HBA215910’ differ in reaction to aluminum sulfate treatment as sterile flower sepals of plants of the new  Hydrangea  treated with aluminum sulfate become red purple to purple violet and yellow green in color whereas sterile flower sepals of plants of ‘HBA215910’ treated with aluminum sulfate become light purple violet in color with greyed red-colored sectors.       

    
    
     
       BRIEF DESCRIPTION OF THE PHOTOGRAPHS 
       The accompanying colored photographs illustrate the unique appearance of the new  Hydrangea  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 from the color values cited in the detailed botanical description which accurately describe the colors of the new  Hydrangea  plant. 
       The photograph on the first sheet is a side perspective view of a typical flowering plant of ‘H218912’. 
       The photograph on the second sheet is a close-up view of a typical inflorescence of ‘H218912’. 
       The photograph on the third sheet is a top perspective view of a typical flowering plant of ‘H218912’ that has been “blued” (left) that is, treated with aluminum sulfate, and a top perspective view of a typical flowering plant of ‘H218912’ that has not been “blued” (right) that is, not treated with aluminum sulfate. 
     
    
    
     DETAILED BOTANICAL DESCRIPTION 
     Plants used in the aforementioned photographs and in the following description were grown during the late spring and early summer in 13-cm containers in a glass-covered greenhouse in De Kwakel, The Netherlands and under cultural practices typical of commercial  Hydrangea  production. During the production of the plants, day and night temperatures averaged 17° C. Plants of the new  Hydrangea  were one year old when the photographs and description were taken. Plants of the new  Hydrangea  can be successfully treated with aluminum sulfate to “blue” the inflorescences. 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 description: Hydrangea macrophylla ‘H218912’.   Parentage:
             Female, or seed, parent .—Proprietary selection of  Hydrangea macrophylla  identified as code number 05-0126-008, not patented.     Male, or pollen, parent.—Hydrangea macrophylla  ‘Green Shadow’, not patented.       
       Propagation:
             Type cutting .—By vegetative tip cuttings.     Time to initiate roots, summer .—About two weeks at temperatures about 23° C.     Time to initiate roots, winter .—About 18 days at temperatures about 20° C.     Time to produce a rooted young plant, summer .—About four weeks at temperatures about 23° C.     Time to produce a rooted young plant, winter .—About five weeks at temperatures about 20° C.     Root description .—Thick; typically whitish 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 .—Freely branching; dense.       
       Plant description:
             Plant and growth habit .—Upright and uniformly mounded plant habit; strong and sturdy stems; rapid growth rate and vigorous growth habit.     Plant height .—About 25 cm to 30 cm.     Plant diameter or area of spread .—About 55 cm to 60 cm.       
       Lateral branch description:
             Branching habit .—Freely branching habit; when pinched, about eight lateral branches develop per plant.     Length .—About 15 cm to 20 cm.     Diameter .—About 6 mm.     Internode length .—About 3 cm to 3.5 cm.     Texture .—Smooth, glabrous; fully developed, woody.     Aspect .—Upright to about 20° from vertical.     Strength .—Strong, sturdy.     Color .—When developing: Close to 146C; at internodes, close to 187A; lenticels, close to 187A. Developed: Close to 146C; at the internodes, close to 187A; when woody, close to 177D; lenticels, close to 187A.       
       Leaf description:
             Arrangement .—Opposite, simple.     Length .—About 10 cm to 13 cm.     Width .—About 6 cm to 8 cm.     Shape .—Ovate.     Apex .—Acuminate to cuspidate.     Base .—Obtuse.     Margin .—Dentate to serrate.     Texture, upper and lower surfaces .—Rugose, glabrous.     Venation pattern .—Pinnate.     Color .—Developing and fully expanded leaves, upper surface: Close to NN137B; venation, close to 145B. Developing and fully expanded leaves, lower surface: Close to 138B; venation, close to 145C.     Petioles .—Length: About 2 cm to 3 cm. Diameter: About 3 mm. Texture, upper and lower surfaces: Smooth, glabrous. Color, upper surface: Close to 145B. Color, lower surface: Close to 145C.       
       Flower description:
             Flower type and habit .—Showy sterile flowers and small inconspicuous fertile flowers arranged on mophead-type terminal panicles; panicles globular in shape; flowers face upright to outwardly depending on their position in the inflorescence.     Fragrance .—None detected.     Natural flowering season .—Plants begin flowering about one year after planting; flowering begins in the early summer and is continuous throughout the summer in Northern Europe.     Flower longevity .—Fertile flowers last about one month on the plant, fertile flowers not persistent; sterile flowers last about four months on the plant, sterile flowers persistent.     Quantity of flowers .—Freely flowering habit; about 40 fertile flowers per panicle and about 80 sterile flowers per panicle.     Panicle height .—About 6 cm to 10 cm.     Panicle diameter .—About 18 cm to 22 cm.     Fertile flower buds .—Length: About 3 mm. Diameter: About 3 mm. Shape: Flattened globular. Color: Close to 144D.     Sterile flower buds .—Length: About 3 mm. Diameter: About 3 mm. Shape: Flattened globular. Color: Close to 145A 63C.     Fertile flower diameter .—About 6 mm.     Fertile flower depth  ( height ).—About 5 mm.     Sterile flower diameter .—About 6 cm to 7 cm.     Sterile flower depth  ( height ).—About 1 cm.     Petals, fertile flowers .—Quantity and arrangement: Four in a single whorl. Length: About 3.5 mm. Width: About 2 mm. Shape: Ovate. Apex: Acute. Base: Obtuse. Margin: Entire. Texture, upper and lower surfaces: Smooth, glabrous. Color: When opening, upper surface: Close to N75C and 149D. When opening, lower surface: Close to 145C. Fully opened, upper and lower surfaces: Close to 72D; color does not change with development.     Petals, sterile flowers .—Quantity and arrangement: Four to five in a single whorl. Length: About 3 mm. Width: About 2 mm. Shape: Ovate. Apex: Acute. Base: Attenuate. Margin: Entire. Texture, upper and lower surfaces: Smooth, glabrous. Color: When opening, upper and lower surfaces: Close to 145D. Fully opened, upper and lower surfaces: Close to N57D; color does not change with development.     Sepals, fertile flowers .—Quantity and arrangement: Five in a single whorl. Length: About 2 mm. Width: About 2 mm. Shape: Ovate. Apex: Acute. Base: Obtuse. Margin: Entire. Texture, upper and lower surfaces: Smooth, glabrous. Color: When opening and fully opened, upper surface: Close to 138A; color does not change with development. When opening and fully opened, lower surface: Close to 138B; color does not change with development.     Sepals, sterile flowers .—Quantity and arrangement: Five in a single whorl. Length: About 2 cm to 4 cm. Width: About 1.5 cm to 2 cm. Shape: Ovate. Apex: Acute. Base: Obtuse. Margin: Entire. Texture, upper and lower surfaces: Smooth, glabrous. Color: When opening, upper surface: Centers, close to 145A and towards the margins and base, close to 63A. When opening, lower surface: Centers, close to 145B and towards the margins and base, close to 63B. Fully opened, upper surface: Centers, close to 146A and towards the margins and base, close to 63A; with development, color becoming closer to 146A with edges, close to 176A; when “blued”, centers become close to 146A and towards the margins and base, close to 64A and N81A. Fully opened, lower surface: Centers, close to 146C and towards the margins and base, close to 63B; color does not change with development.     Pedicels, fertile flowers .—Length: About 1 cm. Diameter: About 1 mm. Strength: Moderately strong. Aspect: Mostly upright. Texture: Smooth, glabrous. Color: Close to 63A.     Pedicels, sterile flowers .—Length: About 2 cm to 2.5 cm. Diameter: About 1.5 mm. Strength: Strong. Aspect: Erect to about 45° from vertical. Texture: Smooth, glabrous. Color: Close to 145B tinged with close to 63B.     Reproductive organs, fertile flowers .—Stamens: Quantity per flower: Eight. Filament length: About 1 mm. Filament color: Close to NN155D. Anther length: About 1 mm. Anther shape: Conical. Anther color: Close to 145D. Pollen amount: Abundant. Pollen color: Close to NN155D. Pistils: Pistil quantity per flower: Three. Pistil length: About 1 mm. Stigma shape: Oval. Stigma color: Close to 150D. Style length: About 1 mm. Style color: Close to 69B. Ovary color: Close to 69B.     Reproductive organs, sterile flowers .—Stamens: Quantity per flower: Eight. Filament length: About 1 mm. Filament color: Close to NN155D. Anther length: About 1 mm. Anther shape: Conical. Anther color: Close to 145D. Pollen amount: Abundant. Pollen color: Close to NN155D. Pistils: Pistil quantity per flower: Three. Pistil length: About 1 mm. Stigma shape: Oval. Stigma color: Close to 155C. Style length: About 1 mm. Style color: Close to 150D. Ovary color: Close to 150D.     Seeds, only produced by fertile flowers .—Quantity per fertile flower: About 20 to 30. Length: About 0.5 mm. Diameter: About 0.1 mm. Color: Close to 200C.       
       Pathogen &amp; pest resistance: Under commercial production conditions, plants of the new  Hydrangea  have not been observed to be resistant to pathogens and pests common to  Hydrangea  plants to date.   Temperature tolerance: Plants of the new  Hydrangea  have been shown to be tolerant to temperatures ranging from about 3° C. to about 38° C.