ILVOHPPRM

Hydrangea

Variety Description

Variety used for comparison: 'Rensun' (Strawberry Sundae)

Summary: The plants of 'ILVOHPPRM' are taller than they are broad and taller than those of ‘Rensun', which are as tall as they are broad. The leaf blade of 'ILVOHPPRM' is larger than that of ‘Rensun'. The inflorescence of 'ILVOHPPRM' is taller and larger in diameter than that of ‘Rensun'. The fertile flowers of the inflorescence of 'ILVOHPPRM' are moderately conspicuous while those of ‘Rensun' are inconspicuous. The calyx of the sterile flower of 'ILVOHPPRM' is larger in diameter than that of ‘Rensun'. The sepal of the calyx of the sterile flower of 'ILVOHPPRM' is longer than that of ‘Rensun'.

Description:

PLANT: non-climbing type, upright to semi-upright growth habit, taller than broad

STEM: no fasciation, red to red brown, medium number of medium sized whitish (tan) lenticels

PETIOLE: red
LEAF BLADE: no lobing, ovate shape, medium to long tip, rounded base, shallow margin incisions, absent or very weak intensity of anthocyanin colouration, no variegation, medium green, no secondary colour, absent or weak glossiness of upper side, medium degree of rugosity, convex in cross-section

INFLORESCENCE: conical shape, moderately conspicuous fertile flowers, medium to dense sterile flowers, pink or red colour at aging on lower part, lower sterile flowers are medium purple red (RHS 55A), medium blue pink (RHS 55B) and light blue pink (RHS 55C) with darker colour along margins, very aged flowers as dark as medium purple red (RHS 58B-C)
STERILE FLOWER: only four sepals
SEPALS OF STERILE FLOWER: semi-erect to horizontal attitude, emarginate apex, absent or weak rugosity, flat in cross-section, absent or very weak to weak overlapping, absent or very weak overlapping when aged, absent or weak undulation, margin incisions absent on all sepals, light yellow green (RHS 2C) to light yellow (RHS 2D) when newly opened, white (RHS 155C) when fully opened, no secondary colour
PETAL OF FERTILE FLOWER: white and pink when closed, white when open

Origin & Breeding History: 'ILVOHPPRM' originated from an open-pollinated cross that occurred between the female parent variety 'DVPPinky' and pollen from an unknown male parent in Melle, Belgium in 2003. In 2005, a single unique seedling was selected from the resulting progeny in Melle, Belgium based on its panicle size, stem colour and flower colour. Asexual reproduction of 'ILVOHPPRM' was first conducted by softwood cuttings in August 2008 in Melle, Belgium.

Tests & Trials: The comparative trial for 'ILVOHPPRM' was conducted in a polyhouse during the summer of 2024 at BioFlora, Inc. in St. Thomas, Ontario. The trial included 10 shrubs each of the candidate and reference variety. All plants were grown from rooted cuttings and transplanted into 13.6 litre containers in the summer of 2023. Observations and measurements were taken from 10 plants, or 10 parts of plants, of each variety on July 27, 2024. All colour determinations were made using the 2015 Royal Horticultural Society (RHS) Colour Chart.

Comparison tables for 'ILVOHPPRM' with reference variety 'Rensun'

Natural plant height including inflorescence (cm)

Leaf blade length (cm)

Leaf blade width (cm)

Inflorescence height (cm)

Inflorescence diameter (cm)

Diameter of calyx of sterile flower (mm)

Length of the sepal of calyx of sterile flower (mm)

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Hydrangea: 'ILVOHPPRM' (left) with reference variety 'Rensun' (right)

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Hydrangea: 'ILVOHPPRM' (left) with reference variety 'Rensun' (right)

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Hydrangea: 'ILVOHPPRM' (left) with reference variety 'Rensun' (right)