Collections of Sitanion hystrix known to differ in phenological development, height, dry matter production, and total water use were examined for possible differences in leaf anatomy and in CO2 assimilation rates. Collections originating in warm, dry habitats produced the narrowest leaves with the fewest veins. Other anatomical characteristics examined were either not different among collections or the differences did not appear to be related to the original habitats. The CO2 assimilation rates were similar on per-unit weight basis; therefore total assimilation varied as a function of plant size.
Clary, Warren P.
"Variation in leaf anatomy and CO2 assimilation in Sitanion hystrix ecotypes,"
Great Basin Naturalist: Vol. 39
, Article 4.
Available at: http://scholarsarchive.byu.edu/gbn/vol39/iss4/4