VARIATION IX ACARATi'M COXVZOiniiS (FAMILY 



composit.f:). 



By Stici'Hkn (.ioTTiiEii, Rkii, M.A., B.Sc. 



In this conmion " Blue Weed" I have charted tlie xariatioii 

 in number of florets in a head, for // specimens studied. Thi- 

 work was done fnmi May 29 to June 2, 1916. 



The results here presented are collected from \atiu-e-Study 

 work of nati\e students under me at Amanzimtoti Institute. The 

 countin^is presented were made l)y them; the collation o\ result^ 

 is mine. 



We examined about one hundred heads of " Blue Weed "' 

 ( Agaratmti coiiyc-oidcs) . Se])aratintj the cluster of heads into 

 its units, I had the students count the number of florets in a 

 head, that they might have a better idea of the nature of the 

 inflorescence in the family Compositje. Owing t(^ choice of iiu- 

 nlature heads, and t(^ known errors in counting. T present the 

 results for jy heads onl}-. This work was done about June i ; 

 I believe that a sttidy at this timt- would show larger numbers of 

 florets per head. 



I classifv the heads in groups with a range of hve florets 

 in each: e.g.. the tirst ("55") is 55 to 59 florets per head. 

 Above 115 per head the rattge is ten florets ])er griuip. Xumber- 

 of heads : — 



Over ^^ florets 1 



60 2 



..65 , 3 



70 () 



.. 73 '<-) 



So (; 



.. -^5 4 



.. 'P 4 



.. 95 ^> 



,. i(X) 7 



,.105 S 



..110 4 



.,115 I 



,. 120. 130 floret > .. .. each j 



.. 140, 130. lOo florets, each 1 



The chief |)oints of interest are: — 



( 1 ) There are Ik'o modes: one at 75 to 71) florets; another 

 at 95 to i(y.) florets. Roughly si)eaking. the former is modal for 

 heads distal in the cluster, ;md the latier for heads centrally 

 k>cated. 



(2) The occasion;il occurrence of lu'ads with uj) to 170 

 florets may be noted. In >uecimens examined a1)ont Jinie J^. 

 ihese lar^e heads aic more plentiful. 



{7,} The innnc-n>c raiuu- of iIr- vai-iation. 



This is contributed as a i)reliminary study only. 1 attempt 

 no inter])retation of the^e residts mitil further work can be added. 



