HENRY, APRIL M.* and KATHLEEN B. PIGG. Department of Plant Biology, Arizona State University, Box 871601, Tempe, AZ 85287-1601 USA. - Hamamelidaceous infructescences from the Late Paleocene Almont, North Dakota flora.
Infructescences of Hamamelidaceae are described from the Late
Paleocene Almont flora of North Dakota. The study is based on
forty-nine specimens that are preserved morphologically with some
details of the fruit wall anatomy. The largest infructescence consists
of up to ten sessile fruits attached to a peduncular axis 8 cm long x
0.5 cm thick. Biloculate fruits are roughly square in outline, around
10-12 mm in dimension, and have persistent, recurved styles on the
distal faces of the carpels. Fruit walls are composed of elongate,
interwoven fibrous cells similar to those seen in extant
Hamamelis. Ellipsoid to ovoid locules are 5-10 mm long x 3-5 mm
wide. Most specimens probably represent senescent fruits lacking
seeds, that may have dehisced explosively like those of some modern
Hamamelidaceae.
Key words: Almont, fossil fruit, Hamamelidaceae, Hamamelis, Paleocene