Mass blooming Calochortus

Diana Chapman
Mon, 21 May 2012 14:45:44 PDT
I was in the Sierra foothills about a month ago for my usual trip to see 
the wildflowers.  Last year I was very dismayed to see that virtually 
all vegetation in one area had been cleared in on both sides of the road 
to a depth of about 20 feet.  This went on for some miles, and was 
probably for fire control.  In a completely different area, similar 
clearing of manzanita had taken place.  This spring there was a mass 
blooming of Calochortus tolmiei in one place and C. monophyllus in 
another.  In both areas (which I know very well) I have never seen 
blooming like this, and in some places I have never seen them blooming 
at all.  This was not a good year for bulb flowers due to the two month 
dry spell we had, so these two areas really stood out.  It has been 
postulated that mass blooming of bulbs after fire could be due to smoke 
penetrating the ground, or to nutrients from the ash, but there were 
neither, just the removal of dense shrubby vegetation, so maybe it isn't 
anything mysterious at all, just the removal of competition, thereby 
making available to the existing bulbs more moisture and nutrients in 
the soil.  I went back this weekend for seed, and another thing struck 
me was that the percentage of plants that set seed in colonies like this 
is very small.  The flowering was amazing, but seed was fairly sparse, 
not even 10% of the individuals producing seed.  the C. monophyllus (it 
is not spotted) literally covers square miles in this area, and the C. 
tolmiei is almost as abundant.


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