.observations on stehgelioid species of vernonia smith,c.earle,1922-
smith,c.earle,1922-
observations on stehgelioid species of vernonia smith,c.earle,1922- - 1st.ed. | .Washington U.S.Agricultural Research 1971
observations on stehgelioid species of vernonia smith,c.earle,1922- - 1st.ed. | .Washington U.S.Agricultural Research 1971