SMNTHDB

Yew

Variety Description

Varieties used for comparison: 'SMNTHDPF' (Stonehenge Skinny) and 'SMNTHDC' (Stonehenge)

Summary: The plants of 'SMNTHDB' have a globose shape while those of both reference varieties have a columnar shape. The plants of 'SMNTHDB' are wider than those of both reference varieties. The branches of 'SMNTHDB' have a semi-erect growth habit while those of both reference varieties have an erect growth habit. The first order branchlet of 'SMNTHDB' is shorter than that of 'SMNTHDC'. The second order branchlet of 'SMNTHDB' is narrower than that of 'SMNTHDPF' and larger than that of 'SMNTHDC'. The prominence of the midrib on the upper side of the leaf blade for 'SMNTHDB' is strong while that of 'SMNTHDPF' is medium and that of 'SMNTHDC' is weak to medium. The upper side of the leaf blade for 'SMNTHDB' has light green variegation at the tip of the margin only while there is yellow variegation at the tip for 'SMNTHDPF' and no variegation for 'SMNTHDC'. The lower side of the leaf blade of 'SMNTHDB' is light green while it is medium green to grey-green for 'SMNTHDC'.

Description:

PLANT: evergreen, globose shape, slow growth rate, medium density of foliage

BRANCHES: high density, medium stiffness, semi-erect growth habit, brown bark
BRANCHLET OF FIRST ORDER: dense, semi-erect growth habit, non-planar arrangement of spray
BRANCHLET OF SECOND ORDER: light green, absent or very weak anthocyanin colouration

PETIOLE: short
LEAF: radially arranged around axis of branchlet, weak fragrance, open
LEAF BLADE: linear shape, acuminate apex, cuneate base, entire margin, flat margin fold, variegation present
LEAF BLADE (UPPER SIDE): weak to medium glossiness, strong prominence of midrib, medium green main colour, very small to small amount of light green secondary colour at tip of the margin only, one-year old summer leaf is medium to dark green (closest to RHS 143A but as dark as RHS 137A)
LEAF BLADE (LOWER SIDE): medium prominence of midrib, glaucosity present on midrib and margin only, light green main colour, one-year old summer leaf is medium green (RHS 144A)

Origin & Breeding History: 'SMNTHDB' originated from an open pollinated cross conducted in 2006 in Grand Haven, Michigan, USA between the Taxus x media variety designated 'Hicksii' as the female parent, and pollen from an unknown male parent. From the resulting progeny, 'SMNTHDB' was selected in 2011 for its plant growth habit, vigour and hardiness. 'SMNTHDB' was first propagated by softwood cuttings in 2011 in Grand Haven, Michigan, USA.

Tests & Trials: The comparative trial for 'SMNTHDB' was conducted in an outdoor irrigated container trial during the spring of 2022 at BioFlora Inc. in St. Thomas, Ontario. The trial included a total of 10 plants each of the candidate and reference varieties. All plants were transplanted into 3.8 liter pots in the summer of 2021. Observations and measurements were taken from 10 plants, or 10 parts of plants, of each variety on July 19, 2022. Mean differences were significant at the 5% confidence probability level based on a paired Student's t-test. All colour determinations were made using the 2015 Royal Horticultural Society (RHS) Colour Chart.

Comparison tables for 'SMNTHDB' with reference varieties 'SMNTHDPF' and 'SMNTHDC'

Plant width (cm)

Branchlet of first order length (cm)

Branchlet of second order length (cm)

Branchlet of second order width (cm)

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Yew: 'SMNTHDB' (left) with reference varieties 'SMNTHDC' (centre) and 'SMNTHDPF' (right)

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Yew: 'SMNTHDB' (left) with reference variety 'SMNTHDC' (right)