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The P&PDL Picture of the Week
for 8 September 2003

Tuliptree Leaf Spot

Karen Rane, Plant Disease Diagnostician, Botany & Plant Pathology, Purdue University

It is late summer, and time for the tuliptree (Lirodendron tulipifera), also known as yellow poplar and tulip poplar, to turn yellow and drop leaves (Figures 1 and 2). This unexplained disorder, apparently induced by environmental stress, commonly develops in tulip trees during hot dry weather after midsummer. An added symptom that frequently accompanies the leaf yellowing is the appearance of circular, black spots between the veins of the yellowing leaves (Figures 3 and 4). The black spots are often mistaken for a fungal leaf spot disease. Though alarming in appearance the problem does not affect tree vigor or health.

Click on the small image to view a larger image.

Figure 1. Tuliptree with
summer leaf drop

Figure 2. Yellow and brown
leaves on a tuliptree branch

Figure 3. Close-up of a tuliptree leaf
showing physiological leaf spot
Figure 4. Tuliptree leaves
with leaf spot


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Last updated: 9 September 2003/amd
The Plant & Pest Diagnostic Laboratory at Purdue University