1-10 Ilex (aquifolium x cornuta) ‘Sled Run’
Male
Registered: April 21, 2010
Dr. James F. Resch
5 Heather Loft Court
Bear, Delaware 19701
The origin of this clone is unknown, but is thought to be a putative chance hybrid seedling of Ilex aquifolium x cornuta. Collected in the late 1960’s, along Satyr Hill Road, Baltimore County, Maryland by Dr. James F. Resch. Dr. Resch grew up at the base of Satyr Hill, which was also home to McLean Nurseries, owned and operated by the late Stewart McLean. Mr. McLean grew at least 300 distinct cultivars of holly in the nursery, which included many large specimen Ilex opaca and Ilex aquifolium as well as numerous other unusual species and hybrids. The diversity of that collection made for a rich gene pool for open pollination. Birds scattered holly seeds freely over Satyr Hill and as a young boy, Dr. Resch collected numerous seedlings from the woods for planting in his parents’ yard in the valley below. The plant which became ‘Sled Run’ was collected as a tiny seedling which caught his eye due to its very glossy green leaves. The original site, north of McLean Nurseries, was also near his favorite winter sledding route and has the approximate GPS coordinates of 39.413, -76.541.
The wild-collected seedling was planted on the north face of Dr. Resch’s parents’ home in Parkville, Maryland (zone 7a) and grew into a small evergreen tree with a horizontal branching habit. After 40 years, the plant exhibited a broadly conical shape, approximately 5.5 m (15 ft.) tall by 4.4 m (12 ft.) wide, with a trunk diameter of 15 cm (6 in.). The plant was a prolific bloomer and grew alongside a large ‘Nellie R. Stevens’ holly which never failed to produce a heavy berry crop. As ‘Sled Run’ matured, its distinctive attribute was the variable nature of the leaf margins. Most leaves were completely lacking marginal spines and were strongly flattened, though some leaves occasionally had one or two marginal spines, while a much smaller number appeared more typical of a traditional I. aquifolium leaf type, with spiny, undulate margins. Unfortunately, the original ‘Sled Run’ in Parkville was removed by the present property owners during landscape renovations in the spring of 2009.
Leaves of ‘Sled Run’ are simple, glossy, coriaceous and of very heavy substance. The largest leaves are 7.5 cm (3 in.) long by 6.0 cm (2 3/8 in.) wide and are orbicular (approximately circular in outline) to broadly oval. The majority of the leaves have completely spineless, flat margins. A minority of the leaves have 1-3 small marginal spines, often inconspicuous and only on one side. Only rarely do leaves appear which are boldly spinose, with up to 5 spines per side, and in rare cases the margins are undulate. Leaf tips are acuminate, with a tip spine to 1-2 mm (1/16 in.) long. Leaf bases are rounded. Petioles are up to 1.4 cm (9/16 in.) long. Leaf color is very dark olive green, Green Group 139A above and Green Group 138A on the underside, on the Royal Horticultural Society Colour Chart, 1995.
Young plants show good apical dominance and may grow about 30 cm (12 in.) per year, but growth slows with maturity and plants tend to broaden. A 17 year old cutting, started in 1992, was 3.3 m (9ft.) tall and nearly equal in width.
‘Sled Run’ has abundant staminate flowers with 4 petals and 4 stamens each, are borne in fasciculate clusters in the leaf axils on previous season’s wood. The flowers are strongly fragrant and attractive to pollinating insects. Buds may show a distinct purplish blush before opening white. ‘Sled Run’ has a very long flowering season, typically beginning a few days before the flowering of I. aquifolium cultivars (e.g. ‘Argentea Marginata’, ‘Lewis’, and ‘Silver Queen’) and nearer to the flowering dates of putative I. aquifolium x cornuta hybrids ‘Nellie R. Stevens’ and ‘Edward J. Stevens’. The last flowering days of this selection often overlap the first few days of the I. opaca bloom period.
Plants have been grown by the selector since 1992 and have been distributed to a small, select group of HSA members. This selection will, however, be distributed at the 2010 HSA National meeting in Oak Ridge/Knoxville, Tennessee, as a test holly. Selection was ultimately based on very broad leaves (nearly as wide as long) with typically spineless margins, glossy dark green color and a long term compatibility with the climate of the mid-Atlantic region. Hardiness is rated at zone 7b on the USDA Plant Hardiness Zone map of 1990. The hardiness range estimate however, is still vague, because of limited distribution of the selection to date.
Voucher specimens are on deposit in the herbarium of the U. S. National Arboretum (NA), Washington, D.C. 20002.
Ilex (aquifolium x cornuta) ‘Sled Run’ in flower April 2009
Photo: James F. Resch
Ilex (aquifolium x cornuta) ‘Sled Run’ in snow March 2009
Photo: James F. Resch
