Praeger, R. Lloyd (Robert Lloyd), 1865-1953, ed. <br/><br/>
An account of the sempervivum group 

 - Lehre  J. Cramer  1967 
 - 265 p.  il. ; 25 cm. 
 - Plant monograph reprints .
<br/><br/><label>Subjects--Topical Terms: </label><br/>SEMPERVIVUM