Koelreuteria” annosa R. W. BROWN

Manchester, Steven R., 2014, Revisions To Roland Brown’S North American Paleocene Flora, Acta Musei Nationalis Pragae Series B 70 (3 - 4), pp. 153-210 : 178

“ Koelreuteria” annosa R. W. BROWN

This name was established by Brown (1956) for an elliptical fin-winged fruit from the vicinity of Jim Bridger coal mine, east of Rock Springs, Wyoming. Later, he included a leaflet, from a different site in Montana, under the same name ( Brown 1962). More specimens of the winged fruit have been recovered from sites near the type locality, but detailed study shows that they are not Koelreuteria . The pedicel is extremely thin compared to that of Koelreuteria , and the fruit has bilateral, rather than trifold, symmetry. The specimens also lack the globose seeds typically found in Koelreuteria fruits, and have a fusiform locular area that is narrower than that of Koelreuteria . Despite a survey of fin-winged fruits in more than 140 extant genera in 45 angiosperm families ( Manchester and O’Leary 2010), it has not been possible to find a close match for these fruits. “ Koelreuteria ” annosa is similar to fruits of extant Rutaceae in being indehiscent, and nonschizocarpic, with hypogynous perianth scar, but the venation is not as reticulate as in extant Ptelea , Balfourodendron , and Spathelia ( Manchester and O’Leary 2010). The association of this species with the foliage illustrated by Brown (1962) is tenuous, and the identification of that specimen requires reexamination.