SMNHMTB

Hydrangea

Variety Description

Varieties used for comparison: 'Paris Rapa' (Cityline Paris) and 'SMHMES14' (Let's Dance Rhythmic Blue)

Summary: The plants of ‘SMNHMTB' are shorter than those of ‘SMHMES14'. The stem of ‘SMNHMTB' has absent or few medium sized blackish lenticels while the stem of ‘SMHMES14' has medium to many small reddish lenticels. The leaf blade of ‘SMNHMTB' is smaller than that of the reference varieties. The incisions along the leaf blade margin of ‘SMNHMTB' are shallow while they are medium to deep for that of the reference varieties. The inflorescence of ‘SMNHMTB' is taller and larger in diameter than that of ‘Paris Rapa' and shorter and smaller in diameter than that of ‘SMHMES14'. The calyx of the sterile flower of ‘SMNHMTB' is smaller in diameter than that of both reference varieties. The incisions along the sepal margin of the sterile flower of ‘SMNHMTB' are absent while they are present for that of the reference varieties. The sepal of the sterile flower of ‘SMNHMTB' is dark blue pink while that of ‘Paris Rapa' is medium purple red.

Description:

PLANT: non-climbing type, upright growth habit, broader than tall

STEM: no fasciation, green, absent or few medium sized blackish lenticels

PETIOLE: green to red
LEAF BLADE: no lobing, ovate to elliptic shape, medium to long tip, obtuse 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, weak to medium degree of rugosity, flat in cross-section

INFLORESCENCE: globular shape, inconspicuous or slightly conspicuous fertile flowers, medium to dense sterile flowers
STERILE FLOWER: three and four sepals
SEPALS OF STERILE FLOWER: semi-erect to horizontal attitude, pointed apex, absent or weak rugosity, weakly concave in cross-section, medium degree of overlapping, absent or weak undulation, margin incisions absent on all sepals, dark blue pink (closest to RHS 63B), no secondary colour

Origin & Breeding History: ‘SMNHMTB' originated from an open-pollinated cross that occurred between the female parent variety 'Cote d'Azur' and the male parent variety ‘PIIHM-II' in Grand Haven, Michigan, USA in the summer of 2015. In 2018, a single unique plant was selected from the resulting progeny in Grand Haven, Michigan based on its growth habit, seasonal changes in foliage colour, flower colour, flowering and reblooming capacity. Asexual reproduction of ‘SMNHMTB' was first conducted by softwood cuttings in 2018 in Grand Haven, Michigan, USA.

Tests & Trials: The comparative trial for ‘SMNHMTB' 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 varieties. 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 June 7, 2024. All colour determinations were made using the 2015 Royal Horticultural Society (RHS) Colour Chart.

Comparison tables for 'SMNHMTB' with reference varieties 'Paris Rapa' and 'SMHMES14'

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)

Colour of sepal of sterile flower (RHS)

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Hydrangea: 'SMNHMTB' (left) with reference variety 'SMHMES14' (right)

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Hydrangea: 'SMNHMTB' (left) with reference varieties 'Paris Rapa' (centre) and 'SMHMES14' (right)

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Hydrangea: 'SMNHMTB' (left) with reference varieties 'Paris Rapa' (centre) and 'SMHMES14' (right)