Japanese Barberry

Denomination: 'Monlers'
Trade name: Golden Nugget
Botanical Name: Berberis thunbergii
Applicant/Holder: Monrovia Nursery Company
18331 East Foothill Boulevard
Azusa, California
United States of America
Breeder: Eilers, Henry, Litchfield, United States of America
Agent in Canada: Cassan Maclean
336 MacLaren Street
Ottawa, Ontario
K2P 0M6
Tel: 613-238-6404 ext. 223
Application Date: 1999-12-16
Application Number: 99-1990
Grant of Rights Date: 2009-05-15
Certificate Number: 3489
Grant of Rights Termination Date: 2027-05-15

Variety Description

Variety used for comparison: 'Aurea Nana'

Summary: The plants of 'Monlers' are smaller with a compact growth habit while those of 'Aurea Nana' are upright. The foliage of 'Monlers' is very dense while that of 'Aurea Nana' is moderately dense. The newly opened leaves of 'Monlers' are lighter yellow than those of 'Aurea Nana'. The upper side of a new, fully expanded leaf of 'Monlers' is dark green with some light green along the edges, initially, while that of 'Aurea Nana' is yellow to yellow green.


PLANT: dwarf type, compact growth habit, very dense foliage

STEM: brownish dark purple red, changes to reddish dark brown when mature/woody, medium thickness, ribbed
BARBS: yellow with moderate anthocyanin colouration, short

NEW LEAF (UPON OPENING): light yellow
NEW LEAF (FULLY EXPANDED): upper side dark green (initially with light green along edges)
MATURE LEAF: alternate arrangement along stem, broad elliptic, broadly acute apex with mucronate tip, cuneate base, dark green upper side, no pubescence

Origin & Breeding History: 'Monlers' was discovered in 1977 within a group of seedlings growing at the H. E. Nursery in Litchfield, Illinois, United States. The seedlings originated from an uncontrolled cross, believed to include Berberis thunbergii variety 'Aurea' and Berberis thunbergii variety 'Kobold' as the parents. 'Monlers' was selected from 50 to 100 seedlings based on its slow growth rate, compact growth habit and golden yellow foliage changing to red orange in the fall. The new variety has been further observed at Monrovia Nursery Company in Dayton, Oregon, United States.

Tests & Trials: Trials for 'Monlers' were conducted in a polyhouse during the summer of 2007 in St. Thomas, Ontario. The trial included a total of 10 plants each of the candidate and reference varieties. The candidate variety was grown in 7.5 litre containers, while the reference variety was grown in 3.8 litre containers during the summer of 2007. Observations and measurements were taken from 2 year old plants, 10 plants of each variety, on July 18, 2007. All colour determinations were made using the 2001 Royal Horticultural Society (RHS) Colour Chart.

Comparison tables for 'Monlers' with reference variety 'Aurea Nana'

Plant height (cm)

  'Monlers' 'Aurea Nana'
mean 16.9 31.3
std. deviation 2.27 6.96

Plant width (cm)

  'Monlers' 'Aurea Nana'
mean 19.6 23.4
std. deviation 2.31 3.38

Colour of leaf (RHS)

  'Monlers' 'Aurea Nana'
newly opened 8B 5A

Colour of new fully expanded leaf (RHS)

  'Monlers' 'Aurea Nana'
upper side 143C (initially, N144B along edges) 5A-154B

Click on image for larger view
Japanese Barberry: 'Monlers' (left) with reference variety 'Aurea Nana' (right)

Click on image for larger view
Japanese Barberry: 'Monlers' (left) with reference variety 'Aurea Nana' (right)

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