Yellow Star-of-Bethlehem is a super plant. This year's count by the Wychwood Flora Group found 12 flowering plants with a total of 22 flowers, a little below average. The number of flowering plants is quite variable year by year and I ran the count dataset which goes back to 1998 against climate statistics for Brize Norton which is the closest weather station that I could find. I could see no meaningful correlations.
What was apparent is that there were very large numbers of non-flowering plants. I selected at random a 5.5m long stretch of the path, counting plants on both sides to a distance of 0.4m on the river side, and 1m on the wooded bank side. In total there was 1 flowering plant (with 3 flowers) against 63 non flowering plants at various stages of development. Someone in the party thought that from seed to flowers takes 6 years, but the number of non-flowering plants is a ratio 10 times that which would be expected. Why do so few plants flower?
|Leaf tip - Yellow Star-of Bethlehem|
|Leaf tip - Bluebell for comparison|
|Non-flowering plants of Yellow Star-of-Bethlehem|
Another of the party suggested we look out for two rust fungi that afflicts Yellow Star-of-Bethlehem. I found both; a round one which I think is Uromyces gageae, and an oblong one, Vankya ornithogali. Only the more mature plants were affected.
|Rust fungus - Uromyces gageae|