Apera

1. Panicle contracted, 0.5–2.5 cm wide, branches densely flowered nearly to the base.

A. interrupta

1. Panicle more diffuse and broad, mostly 3.5–10 cm broad, panicle branches not bearing spikelets to the base.

A. spica-venti

All species found in Apera

Apera interruptaAPERA 
Apera spica-ventiAPERA 

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. October 19, 2017. http://michiganflora.net/genus.aspx?id=Apera.