TY  - BOOK
AU  - Clausen,Jens
TI  - Stages in the evolution of plant species / 
U1  - 581.38 CLA  
PY  - 1967///
CY  - New York : 
PB  - Hafner Publishing Company
KW  - Evolution -- plant species
KW  - Plant -- diseases
KW  - Plants -- Evolution
N1  - Includes index.
ER  -