Berriochloa gabeli n. sp. and Berriochloa huletti n. sp. are described from fossil anthoecia (husks) recovered in late Miocene (Ash Hollow Formation) sediments in central Nebraska and central and western Kansas. Comparisons with other known fossil and living grasses suggest relationships with members of the grass tribe Stipeae and previously described B. intermedia Elias, 1942 from Ash Hollow deposits in north-central Kansas. Berriochloa gabeli and B. huletti were recovered in direct association with, or in the close vicinity, of rich biotas that provide evidence of widespread, probably treeless, grasslands with adjacent moist riparian habitats along streams or around temporary pools of water during deposition. Fossil vertebrates associated with the grasses at some sites suggest that the age of B. gabeli and B. huletti is early to middle Hemphillian.

Systematically diverse assemblages of fossil plants have been collected in late Miocene strata at seven sites in northern Antelope County, Nebraska. Fossils were found in several members of the Valentine and Ash Hollow Formations of late Barstovian to medial Clarendonian (13–10 MYBP) age and unnamed members of the Ash Hollow Formation of late Clarendonian to early Hemphillian (9.5–8.0 MYBP) age. Seeds, fruits, and leaf-sheath fragments of 18 species from the families Equisetaceae, Cyperaceae, Gramineae, Boraginaceae, Juglandaceae, and Ulmaceae are described. These occurrences represent a 200 mile (322 km) eastward extension of the known geographic range of all of the taxa during the Miocene. The occurrence of Juglandaceae is the first reported from widespread Miocene strata of the Ogallala Group in central North America.