An Etymological Dictionary of the German Language/Blume
Blume, f., ‘blossom, flower,’ from MidHG. bluome, m., f., OHG. bluoma, f. (bluomo, m.); comp. OSax. blômo, Goth. blôma, AS. blôma, E. bloom. -man-is a deriv. suffix; the root blô (see blühen) shows that Blume is lit. ‘the blooming plant.’ The following are also Teut. cognates of Blume: — Du. bloesem (besides bloem), AS. blôstm, blôstma, E. blossom; perhaps their s belongs, however, to the root; this is indicated by MidDu. blôsen, ‘to bloom,’ which points to the close connection between E. blossom and Lat. florere for *flôsê-re, flôs (flôr-is for *flôsis). A root bhlô without this s appears in OIr. bláth, ‘blossom,’ E. dial. blooth, ‘flower.’ See further the following word, also Blüte and Blatt.