The following case was brought forth by Detective Marian Kleinwort PSI ISU. The facts of the case were:
1. Original purchase 6 years ago as seed from catalog - unknown; plant name - unknown
2. Leaves appear on new stems at the end of May into June
3. Stems grow very fast in summer sometimes reaching 15 ft.; one witness reported that some of the stems grew 12 - 15 inches in one day this summer
4. Witnesses reported that all growth in the picture was from this year's growth
5. No flowers are produced
6. Leaves do not change color in fall
7. Stems are solid early but become hollow later in the year
6. Each year the shoots die back to the ground and new shoots appear
9. Clumps of the plant have been given to neighbors who report that they have had the plant for 3 years
10. A similar plant is believed to have been observed in a neighboring town
Special Investigator Dr. Mary Meyer was called in as a special consultant on the case. Her findings were as follows:
Genus and species Paulownia tomentosa; Family: Bignoniaceae
Common name: princess-tree; Synonym(s): empress-tree
Consulting Plant Psychologist Dr. Karl Foord was asked to explain the bizarre behavior of this plant.
His findings are as follows:
Plant is reportedly hardy to zone 5b. When growing in its adapted environment its leaves will turn yellow in the fall. Apparently the early frosts kill the leaves before they develop color. It appears that the underground trunk tissue is not killed in this climate and new sprouts appear each year. The great vigor of the young shoots is characteristic of this plant. Because the stems never survive more than one year, any flower buds produced in the first year of growth are killed. This is exactly the way my non-northern strain of Redbud (Cercis canadensis) plants behaves. No trunk is ever established and the plant produces several trunk sprouts which die back to the ground each year.
Editor's note: Thanks to Marian Kleinwort, UMN Extension Master Gardener - Dodge County, for submitting pictures of the sample and the facts about the case. Thanks to Dr. Mary Meyer, UMN Horticulture Science Professor, for identifying the plant.