Elm tree variety named Wideleaf

#The present invention relates to a new and distinct variety of Elm tree which is believed to be a third generation tree resulting from the interspecific hybridization of Ulmus americana.times.U. pumila. The tree of this invention is also believed to be the result of a series of natural pollination back crosses of the initial hybrid with either American Elm or other hybrid trees with the same genetic background, due to the numerous characteristics of this tree which characterize American Elm, yet differing in a number of respects, such as having an unusually high level of vigor and by producing leaves which are much larger than those of either U. americana or U. pumila. This tree produces leaves which are most similar to those of the American Elm, but differ slightly in terms of shape and length of leaf stem; the leaves of this tree being nearly symmetrical and having uncharacteristically short petioles. The veins of the leaves of this tree are inserted from the top surface and protrude from the bottom leaf surface to a higher degree than is characteristic for American Elm, and venation is inconspicuous from the top, but very conspicuous from the bottom surfaces of the leaves, which are also thicker than is characteristic of those of the American ancestor species. While this selection has not been systematically tested for a long period of time, its characteristics which would qualify it is useful to both the landscape artisan and a farmer wishing to grow a living windbreak. Due to the age, size and character of its known seed parent, it is believed that this tree will be unusually tolerant of, or resistant to, common diseases which discourage the planting of trees within the family Ulmaceae.

#Testing was done by obtaining leaf and stem material from an American Elm dying of Dutch Elm disease and grinding it to a pulp, and on Jul. 20, 1991 inoculating each of 20 third generation elms which were 5 to 6 feet high by making a one-inch incision through the bark, prying the bark back slightly and inserting the pulp, pressing more on the outside and wrapping the whole with masking tape. From this they showed no signs of wilting, and I repeated the inoculation the next year in July of 1992 on all 20 trees in the same manner, and also as a check I inoculated 8 American Elm in a nearly lot, leaving four that were not inoculated. The 20 of this third generation of trees show no sign of disease, while all eight of the American Elm trees are dead or dying of it, and the four trees that were not inoculated show no signs of disease yet.

#This tree was a seedling selected from among the progeny of a mature Elm tree which bore characteristics of both U. americana and U. pumila, and which showed unusual resistance to common elm diseases, had an attractive upright habit, unusually ascending branch attitude and a straight, long, stately bole. This tree was believed to have been a second generation open pollinated seedling of the two species named above. A planting of seeds collected from the parent tree was made by me to form a nursery from which superior trees could be selected. This tree was selected as being exceptional within the population due to its high vigor which resulted in growth rate and size attainment of nearly twice that of the siblings at the time of selection, and because of the unusual, desirable characteristics of its leaves as noted above. I have asexually reproduced this tree by layered cuttings in the yard of my nursery in Winnebago, Wis. Clones of this tree are substantially identical to the original selection in all distinguishing characteristics, which have been reliably expressed in clonal material to demonstrate that the tree is stable.

#The first sheet of drawing contains 4 photographs which show, in turn:

#At the top left, a specimen of the claimed tree in its fourth season of growth. This photograph depicts the presentation of leaves of the canopy, comparative leaf size and leaf spacing along the forming central leader and scaffold branches.

#The top right photograph depicts the same specimen, against a contrasting background, in dormancy. The placement and angle of lateral branches and the color of the bark in dormancy can be seen in the specimen. The development of a fairly strong, straight central leader can also be seen in this view, with the healing lesion, about in the center of the photograph, resulting from inoculation testing of the tree as described above.

#Stems:

#Length.--I. Length of new growth to 4 years old 18 in. -- 81/2 ft.: Ulmus Wideleaf. I. Length of new growth to 4 years old 8 in. -- 2 ft.: Ulmus americana.

#Attachment.--I. Thickening of trunk around base of attached branch: Ulmus Wideleaf. I. Thickening not evident at base of branches: Ulmus americana.