U.S. patent number PP15,944 [Application Number 10/768,784] was granted by the patent office on 2005-09-06 for birch tree name `verdale`.
This patent grant is currently assigned to NDSU Research Foundation. Invention is credited to Larry J. Chaput, Zong-Ming Cheng, Wenhao Dai, Dale E. Herman, Victoria A. Magnusson.
United States Patent |
PP15,944 |
Herman , et al. |
September 6, 2005 |
Birch tree name `VerDale`
Abstract
`VerDale` is a new cultivar of Betula platyphylla, Asian white
birch. This new cultivar has white bark and dark green leaves in
addition to being highly resistant to bronze birch borer (Agrilus
anxius Gory).
Inventors: |
Herman; Dale E. (Fargo, ND),
Chaput; Larry J. (Fargo, ND), Cheng; Zong-Ming
(Knoxville, TN), Dai; Wenhao (Fargo, ND), Magnusson;
Victoria A. (Hawley, MN) |
Assignee: |
NDSU Research Foundation
(Fargo, ND)
|
Family
ID: |
34807954 |
Appl.
No.: |
10/768,784 |
Filed: |
January 30, 2004 |
Current U.S.
Class: |
PLT/216 |
Current CPC
Class: |
A01H
5/00 (20130101) |
Current International
Class: |
A01H 005/00 () |
Field of
Search: |
;PLT/216 |
Primary Examiner: Grunberg; Anne Marie
Attorney, Agent or Firm: Jondle & Associates P.C.
Claims
What is claimed is:
1. A new and distinct Betula platyphylla birch tree as shown and
described herein.
Description
Genus and species: Betula platyphylla.
Cultivar denomination: `VerDale`.
BACKGROUND OF THE INVENTION
The present invention comprises a new and distinct cultivar of
birch tree, botanically known as Betula platyphylla, and
hereinafter referred to by the cultivar name `VerDale`. `VerDale`
is a product of a planned tree selection program which had the
objective of creating a new cultivar of birch tree having high
bronze birch borer resistance, good birch leafminer resistance and
various aesthetic qualities as listed in the Detailed Description
of the Plant.
The new cultivar is a selection of Betula platyphylla, and was
discovered by applicant among seedlings grown from parental trees
growing on the NDSU campus and was transplanted on Sep. 22, 1975
into the NDSU Research Arboretum, Absaraka, N. Dak. The selection
was noticed by virtue of its long term bronze birch borer
resistance; white bark; quality dark green foliage and excellent
golden-yellow autumn foliage coloration; upright, oblong-elliptical
form becoming broadly pyramidal with maturity.
The first act of asexual reproduction of `VerDale` was accomplished
when plants were produced in tissue culture using standard
micropropagation techniques by applicant from the initial selection
on Nov. 13, 2000 in a controlled environment in Fargo, N. Dak.
(NDSU). Horticultural examination of selected units initiated on
Nov. 13, 2000 has demonstrated that the combination of
characteristics as herein disclosed for `VerDale` are firmly fixed
and are retained through successive generations of asexual
reproduction.
`VerDale` has not been observed under all possible environmental
conditions. The phenotype may vary with variations in environment
such as temperature, light intensity, and day length. The following
observations, measurements and comparisons describe the plants
grown in the NDSU Research Arboretum or under greenhouse
conditions, which approximate those generally used in commercial
practices.
This new birch tree is illustrated by the accompanying photographs
which show the entire tree, foliage closeup and bark features, the
colors shown being as true as can be reasonably obtained by
conventional photographic procedures.
FIG. 1 shows the complete tree in dense foliage;
FIG. 2 shows the dense foliage;
FIG. 3 shows the bark color and exfoliation on the trunks; and
FIG. 4 is a close-up of the leaves.
DETAILED DESCRIPTION OF THE NEW PLANT
The following traits and characteristics describe the new cultivar.
Classification: Origin.--Seed source is unknown. Species.--Betula
platyphylla. Common names.--Asian White Birch.
TREE Trunk: Multiple stem.--Two main trunks forming clump.
Size.--At 29 years of age, average diameter of two trunks, 30.7 cm
measured at 127 cm above the ground. Bark.--Color ranges from RHS
155B to RHS 155C, average length of exfoliating sheets 2.2 cm.
Height.--At 29 years of age, 14.6 m. Growth habit or form.--Upright
oblong to semi-pyramidal becoming broadly pyramidal with age.
Growth rate.--50.3 cm/year (under sod conditions in arboretum, no
supplementary irrigation or fertilization). Branches: Angle of
attachment.--Average angle of 25 branches, 47.0 degree.
Spacing.--Variable. Size.--Crown diameter of tree, 6.3 m at 29
years. Bark.--Prior to bark changing to white, branches aged 2-4
years range in color from greyed-orange (RHS 166A/B) to brown (RHS
200A). Lenticels: Size.--1-2 mm. on branches less than one inch in
diameter. Color.--Whitish. Quantity.--Many. Buds: Length.--6-10 mm;
average 8.2 mm. Width.--2-3 mm; average 2.7 mm. Shape.--Imbricate,
pointed. Pubescence.--Scattered. Bud pubescence color.--RHS 200A
(Brown). Bud color.--Ranges from RHS 146B to RHS 146C. Time of leaf
out.--Varies from May 1-15. Foliage: Size of leaf.--Length -- Range
7.5-10.7 cm, average 8.8 cm. Width -- Range 5.2-7.9 cm, average 6.5
cm. Shape of leaf.--Ovate-triangular to ovate-deltoid. Margin --
Doubly-serrate. Texture -- Medium. Pubescence
distribution.--Glabrous on both leaf surfaces, except scattered
hairs on main vein (midrib) and lateral veins, more prevalent on
bottom side. Color.--Upper side, RHS 137A (green). Underside, RHS
148B (yellow-green). Autumn color.--RHS 17C (yellow-orange).
Petiole.--Range from 1.9-2.8 cm, average 2.3 cm. Ribs and
veins.--Average of 9 vein pairs per leaf. Thorns and spines.--None.
Buds.--Imbricate, pointed, scattered hairs.
CATKINS Staminate: Shape.--Cylindrical, dormant stage fairly rigid,
blooming stage, pendulous. Size.--Dormant stage length 1.2-2.8 cm,
average 2.0 cm. Blooming stage 4.2-8.4 cm, average 6.4 cm. Scales:
Shape.--Teardrop to diamond-shaped, dormant stage. Color.--RHS 200D
(brown) to RHS 6C/D (yellow). Pistillate: Shape.--Cylindrical;
blooming stage, not pendulous. Size.--Blooming stage 1.2-2.8 cm,
average 2.0 cm. Scales: Shape.--Teardrop to diamond-shaped.
Color.--RHS 149A (yellow-green) to RHS 144C (yellow-green). Timing
of appearance, staminate, and pistillate catkins:
Staminate.--Develop during summer. Pistillate.--Develop May 5-20.
Timing of anthesis.--May 1-15, varies with year. Fruit: Strobile
bearing, many winged nutlets (seeds) which average 5 mm long and 5
mm wide. Shape.--Cylindrical. Length.--2.7-4.2 cm, average 3.6 cm.
Width.--0.6-0.8 cm, average 0.7 cm. Color.--Yellow-green (RHS
146C), changing to brown in the fall.
INSECT AND DISEASE RESISTANCE
No evidence of bronze birch borer attack in 29 years of evaluation
in large birch collection in the NDSU Research Arboretum where
borer population and death of other birch accessions has been high.
Resistance to birch leaf miner has been good to date.
COMPARISON WITH MOST SIMILAR CULTIVAR
Of the many commercial birch trees known to the applicant, the most
similar in comparison to `VerDale` are the other introduced Betula
platyphylla cultivars, such as Betula platyphylla `Fargo` (U.S.
Plant Pat. No. 10,963). The latter cultivar tends to have somewhat
smaller and glossier leaves compared to `Verdale` and it produces a
narrow, columnar growth habit. The mature height of `Fargo` is also
less than `VerDale`. In comparison to `Fargo`, `VerDale` has a
number of important attributes such as being highly bronze birch
borer (Agrilus anxius Gory) resistant. The bark on stems of
`VerDale` begin changing to whitish at 8-15 mm in diameter.
`VerDale` has quality dark green foliage and excellent
golden-yellow autumn foliage coloration. `VerDale` has good
resistance to birch leaf miner (Fenusa pusilla Lepeletier) and is
very winterhardy (withstanding winter temperatures of -35.degree.
to -40.degree. C.
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