St Barnaby's thistle, yellow burr

Centaurea solstitialis


St Barnaby's thistle (Clemson, p. 213) is valued both for its pollen and its honey. The pollen is of reasonable quality with a range of crude protein of 18% to 26%, but is limited by its low level of iso-leucine (Table 9). However the large volume of pollen and the heavy nectar flow make it a valuable autumn bee food.

For best results from St Barnaby s thistle, there needs to be good ground moisture, and the bees allowed to access this floral source for six to eight weeks. Some beekeepers leave their bees on St Barnaby s thistle all autumn.

It is reported that queen bees bred on St Barnaby's thistle are usually of high quality.

Table 9: St Barnaby's thistle, yellow burrCentaurea solstitialis


Amino-acid
Minimum % of Amino-Acid from De Groot (1953)
Swan Vale Glen Innes

March 86

King's Plain Inverell

March 87

Glen Innes March 92
Threonine
3.0
3.44 4.44 3.8
Valine
4.0
3.55* 4.05 4.4
Methionine
1.5
1.47* 2.06 1.9
Leucine
4.5
5.18 6.67 6.3
Iso-leucine
4.0
2.87* 3.34* 3.9*
Phenylalanine
2.5
3.14 4.52 3.5
Lysine
3.0
5.91 5.51 4.3
Histidine
1.5
3.03 4.19 2.5
Arginine
3.0
4.87 5.04 4.7
Tryptophan
1.0
- - -
Crude protein
-
22.4% 18.68% 26.4%
Fat   8%    

*Low level of this amino-acid


 



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