Hydrangea plant named ‘SMHAMWM’

Abstract

A new and distinct Hydrangea cultivar named ‘SMHAMWM’ is disclosed, characterized by large inflorescence, strong flowering stems, bright white blossoms and compact habit. The new variety is a Hydrangea, normally produced as an ornamental plant for containers or gardens.

Claims

1. A new and distinct cultivar of Hydrangea plant named ‘SMHAMWM’ as herein illustrated and described.

Description

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

(1) The accompanying photograph in FIG. 1 illustrates in full color a typical mature flowering plant of ‘SMHAMWM’ grown in a field, in Grand Haven, Mich., USA. Age of the plant photographed is approximately 2-3 years.

(2) FIG. 2 illustrates a non-flowering plant in a 1 gallon container, at approximately 1 year.

(3) The photographs were taken using conventional techniques and although colors may appear different from actual colors due to light reflectance it is as accurate as possible by conventional photographic techniques.

DETAILED BOTANICAL DESCRIPTION

(4) In the following description, color references are made to The 1996 Royal Horticultural Society Colour Chart except where general terms of ordinary dictionary significance are used. The following observations and measurements describe ‘SMHAMWM’ plants grown in a double poly greenhouse in Grand Haven, Mich., USA in a 2 gallon pot. The growing temperature ranged from approximately 18° C. to 27° C. daytime and 10° C. at night. Measurements and numerical values represent averages of typical plant types. Measurements were taken during July of 2015. Botanical classification: Hydrangea arborescence ‘SMHAMWM.’

PROPAGATION

(5) Time to initiate roots: Approximately 20 days at approximately 24° C. Time to produce a rooted young plant: Approximately 60 days at approximately 24° C. Root description: Thin root thickness, high root density, freely root branching, fibrous. Color is white, not accurately measured with R.H.S. chart. Propagation method: Softwood cuttings.

PLANT

(6) Age of plant described: 2-3 years. Pot size: 2 gallon. Growth habit: Flowering perennial shrub, upright/rounded. Overall plant shape: Upright. Height: 70 cm. Plant spread: 50 cm. Growth rate: Good. Plant vigor: Good. Branching characteristics: Basal branches from base or ground level, pinching required. Length of lateral branches: 50-70 cm. Number of lateral branches: 25. Diameter of lateral branches: 6 mm. Lateral branch shape and appearance: Round. Lateral branch strength: Good. Internode length: 9 cm. Branch color: Immature.—Near RHS Yellow-green 145C. Mature.—Near RHS Yellow-green 145A with striations of Greyed-purple 187B. Branch aspect: Upright. Branch pubescence: Slight.

FOLIAGE

(7) Leaf: Arrangement.—Opposite. Average length.—14.5 cm. Average width.—10.4. Shape of blade.—Ovate. Apex.—Acute. Base.—Rounded to cordate. Margin.—Serrate to serrulate. Texture and appearance of top surface.—Slightly pubescent. Texture and appearance of bottom surface.—Slightly pubescent. Color.—Young foliage upper side: Near RHS Green 143B. Young foliage under side: Closest to RHS Green 138C. Mature foliage upper side: Near RHS Green 141B. Mature foliage under side: Near RHS Green 138C. Venation.—Type: Pinnate. Venation color upper side: Near RHS Yellow-green 146C. Venation color under side: Near Yellow-Green 145B. Petiole: Average length.—6.5 cm. Diameter.—3 mm. Color.—Upper side: Near RHS Yellow-green 145A with striations of Greyed-purple 187B. Under side: Near RHS Yellow-green 145B. Texture upper side.—Smooth and pubescent. Texture under side.—Smooth and pubescent.

FLOWER

(8) Bloom period: Natural season.—Mid-Summer until Fall. Inflorescence: Type.—Mophead. Quantity of flowers per inflorescence.—Fertile flowers, 50-100. Sterile Flowers, About 1000. Persistent or self-cleaning.—Persistent. Fragrance.—Slightly sweet. Panicle: Shape.—Semi-orbital to cyme. Height.—10 cm. Diameter.—22 cm. Sterile flower: Androecium.—Yes. Bud shape.—Obovate. Bud length.—2 mm. Bud diameter.—2 mm. Bud color.—Near RHS Red-purple 69B. Flower aspect.—Upright and outward. Flower shape.—Cruxifix. Flower length.—2 cm. Flower diameter.—2 mm. Flower depth.—2 cm. Sterile flower petals: Petal arrangement.—Whorl. Length of petal.—2 mm. Width of petal.—1 mm. Apex.—Acute. Shape of petal.—Ovate. Petal margin.—Entire. Petal base.—Rounded to obtuse. Petal number.—4. Petal texture.—Smooth, coriaceous, upper and under side. Color.—Upper surface at first opening: Near RHS White 155B. Upper surface at maturity: Near RHS White 155B. Under surface at first opening: Near RHS White 155B. Under surface at maturity: Near RHS White 155B. Sterile flower sepal: Arrangement.—Whorl. Number.—4-5. Shape.—Ovate. Tip.—Acute. Base.—Obtuse. Margin.—Entire. Length.—1 cm. Width.—1 cm. Texture, upper.—Smooth, coriaceous. Texture, lower.—Smooth, coriaceous. Color.—Upper surface at first opening: Near RHS White 155B. Upper surface at maturity: Near RHS White 155B. Under surface at first opening: Near RHS White 155B. Under surface at maturity: Near RHS White 155B. Fading to Upper surface: Near RHS White 155B. Fading to Under surface: Near RHS White 155B. Sterile flower pedicel: Length.—1 cm. Diameter.—1 mm. Angle.—Upright and outward. Strength.—Good. Texture.—Smooth. Color.—Near RHS Yellow-green 145B. Fertile flower: Bud shape.—Obovate. Bud length.—2 mm. Bud diameter.—2 mm. Bud color.—Near RHS Red-purple 69B. Flower aspect.—Upright and outward. Flower shape.—Star-like. Flower length.—5 mm. Flower diameter.—5 mm. Flower depth.—4 mm. Fertile flower petals: Length of petal.—1.5 mm. Width of petal.—1 mm. Apex.—Acute. Shape of petal.—Ovate. Petal margin.—Entire. Petal arrangement.—Whorl. Petal number.—5. Petal base.—Rounded. Petal texture.—Smooth, upper and under side. Color.—Upper surface at first opening: Near RHS White 155B. Upper surface at maturity: Near RHS White 155B. Under surface at first opening: Near RHS White 155B. Under surface at maturity: Near RHS White 155B. Upper surface fading to: Near RHS White 155B. Lower surface fading to: Near RHS White 155B. Fertile flower pedicel: Angle.—Upright/outward. Strength.—Good. Length.—4 mm. Width.—0.5 mm. Texture.—Smooth. Color.—Near RHS Yellow-green 145A. Fertile flower sepal: Arrangement.—Whorl. Number.—5. Shape.—Ovate. Tip.—Acute. Base.—Fused. Margin.—Entire. Length.—1 mm. Width.—1 mm. Texture, upper.—Smooth. Texture, lower.—Smooth. Color.—Upper surface at first opening: Near RHS Yellow-green 150C. Upper surface at maturity: Near RHS Yellow-green 150C. Under surface at first opening: Near RHS Yellow-green 150C. Under surface at maturity: Near RHS Yellow-green 150C. Upper surface fading to: Near RHS Yellow-green 150C. Lower surface fading to: Near RHS Yellow-green 150C.

REPRODUCTIVE ORGANS

(9) Sterile flower: Stamen number.—8. Filament length.—0.7 mm. Filament color.—Near RHS White 155B. Anther shape.—Rounded, fusiform. Anther color.—Near RHS Red-purple 65A. Anther length.—1 mm. Pollen amount.—None. Gynoecium.—Yes. Pistil number.—1. Pistil length.—2 mm. Stigma shape.—Blunt. Style length.—1 mm. Style color.—Near RHS Yellow-green 145B. Fertile flower: Stamen number.—10. Filament length.—1 mm. Filament color.—Near RHS White 155B. Anther shape.—Rounded. Anther length.—1 mm. Anther color.—Near RHS Red-purple 65A. Pollen amount.—Some. Pollen color.—Near RHS White 155B. Pistil number.—2. Pistil length.—2 mm. Stigma shape.—Rounder. Stigma color.—Near RHS Yellow 10D. Style length.—1 mm. Style color.—Near RHS Yellow 10D. Ovary color.—Near RHS Yellow 10D.

OTHER CHARACTERISTICS

(10) Disease resistance: Neither resistance nor susceptibility to diseases or pests has been observed in this variety. Cold tolerance: −31° C. to 38° C. Fruit/seed production: 1000's of seeds produced. Abundant, minute seed produced. Seed less than 1 mm in diameter and length, brown, too small to accurately measure with R.H.S. chart.