This is the publisher's version, also available electronically from: http://www.jstor.org/stable/2995468.Three species of the C4 grass genus Muhlenbergia—M. frondosa, M. sobolifera, and M. schreberi—
were collected from forest understory sites in northeastern Kansas and grown in a growth chamber at 1,500,
150, and 15-25 fjimol m~2 s - 1 photosynthetic photon flux density (PPFD). Leaf, stem, root, and total
biomasses and several morphological and anatomical characteristics were measured after 35-38 days. Results
were compared with similar measurements for M. cuspidata collected from exposed prairie sites. Although
all species grew maximally at the highest PPFD, M. sobolifera grew equally well at medium PPFD.
Few anatomical changes were correlated with changes in PPFD except leaf thickness, which increased with
increasing PPFD. The results indicate that, while the understory species of Muhlenbergia can adjust morphologically
to some extent to shaded environments, they produce more biomass at higher PPFD
