Birch tree named &#8216;Cenci&#8217;

The present invention comprises a new and distinct cultivar of a birch tree, botanically known as Betula papyrifera , and is hereto referred to by the cultivar name Cenci .

BACKGROUND OF THE INVENTION

Cenci was discovered by the inventor in a group Betula papyrifera in a provenance test plot planted in Wooster, Ohio in 1986. Cenci was originated from the open pollinated cross in a birch selection/breeding program on Evergreen Nursery Company property. The female parent was Betula papyrifera . The male parent is unknown. Cenci was first noticed with a tight, oval, compact growth habit, white large, shaggy, persisting exfoliating bar and a high resistance to the Bronze Birch Borer. The cultivar has been asexually reproduced in Sturgeon Bay, Wis. and Wooster, Ohio. Presently, reproduction is accomplished by micropropagation or tissue culture propagation by the inventor from the initial selection in Sturgeon Bay, Wis. Horticultural examination of selected units has demonstrated that the combination of characteristics has herein disclosed for Cenci are firmly fixed and retained through its successive generations of asexual reproduction. Cenci has been observed in Sturgeon Bay, Wis., and Wooster, Ohio, since 1986 and characteristics have been stably maintained. The cultivar reproduced true to type. The new cultivar has not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment such as temperature, day length and light intensity, without a change in the genotype of the new cultivar. The following observations, measurements and comparisons describe the plants grown in Sturgeon Bay, Wis. under natural field conditions which approximate those generally used in commercial growing operations.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and are determined to be basic characteristics of Cenci which in combination distinguish this birch tree as a new and distinct cultivar:

1. Distinctive tight, oval, compact growth habit with a good central leader and branching angles about 35-40 .

2. Bark color changes as the tree matures; from brown turning to white.

4. High resistance to the Bronze Birch Borer.

5. Slow to moderate growth rate.

The new cultivar can be compared to the non patented Betula papyrifera for the foregoing characteristics differ from the nonpatented variety in that the nonparented variety has variable resistance to the Bronze Birch Borer, has a loose oval growth habit and the bark exfoliates in smaller pieces.

DETAILED BOTANICAL DESCRIPTION

In the following description, color references are made to The Royal Horticultural Society (R.H.S.) Color Chart. The color values were determined in natural light in August 1999 in Sturgeon Bay, Wis.

Origin. Found as a seedling in a group of Betula papyrifera in a provenance test plot in Wooster, Ohio in 1994.

Trunk. Single-trunked tree. Size: Diameter at age 10 is approximately 11.1 cm. at 1.2 m above the ground. The height is 6.6 m.

Height. 6.6 m at about 10 years of age.

Growth habit or Form. Tight, oval compact; when tree is 6.6 m high, it is about 3.6 m wide. Growth rate: slow to moderate, about 0.5-1.0 meters per year, depending on summer temperature, fertility and water availability.

Disease and pest resistance: High resistance to Bronze Birch Borer as compared with other trees in an area of heavy Birch Bar Borer infestation in Wooster, Ohio and Sturgeon Bay, Wis. Highly resistant to Leafhoppers.

Winter hardness/drought/heat resistance: Winter hardiness in Zone 3 and good drought/heat resistance in Zone 7.

Flowers: No

Reproductive organs: Male catkins borne at end of branches, female catkins are borne upright and several nodes behind male catkins.