Searching for Euphorbia hooveri – Esquon Lake, 11 Aug 2019

I visited Esquon "Lake" (a vernal pool now heavily surrounded by grass under a grazing regime) to look for the late-blooming Euphorbia (=Chaemasyce) hooveri; a rare and threatened plant (CRPR 1B.2).

My understanding was to look for areas of open, cracked mud in what would have been the vernal pool's last spots to dry. I found very little of this presumed appropriate habitat, apparently the surrounding grass and other graminoid vegetation has encroached heavily into the middle of the pool. Although little else was blooming, remnant vegetation of Marsilea, Navarretia, Eryngium etc. indicated that it is still home to a significant wet grassland pool flora.

I found thousands of Euphorbia ocellata subsp. ocellata in the more bare mud areas, but they also extended deeply into the surrounding grassland.

I found 0 Euphorbia hooveri.

Witham, 2013 (in my opinion, optimistically) lists this occurrence as "presumed extant".

From Witham, 2013:
[This site] heavily grazed and trampled, but occurrence is doing fine (1986). Unknown number seen in 1980. 1000‐2000 plants observed in 1986. Under the current grazing regime, this population is large and probably stable." "Surveyed 09‐09‐2010. Habitat present but no plants found." "...no plants seen 2007‐2011."

Publicerat 11 augusti 2019 16.55 av leptonia