Searching for Euphorbia hooveri – Esquon Lake, 11 Aug 2019

August 10, 2019 17:00 - August 10, 2019 18:00
| Latitude: 39.635 | Longitude: -121.706 | Radius (m): 128 | Distance traveled: 900m | Duration: 60 minutes | Number of observers: 1 |

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."

Posted by leptonia leptonia, August 11, 2019 16:55

Target List

  • Hoover's Spurge (Euphorbia hooveri)
  • Observations

    Photos / Sounds

    What

    Turkey Mullein (Croton setiger)

    Observer

    leptonia

    Date

    August 10, 2019 10:50 AM PDT

    Photos / Sounds

    What

    Scarlet Toothcup (Ammannia coccinea)

    Observer

    leptonia

    Date

    August 10, 2019 10:49 AM PDT

    Description

    Perhaps?

    Photos / Sounds

    What

    Valley Spurge (Euphorbia ocellata ssp. ocellata)

    Observer

    leptonia

    Date

    August 10, 2019 10:46 AM PDT

    Photos / Sounds

    What

    Fitch's Tarweed (Centromadia fitchii)

    Observer

    leptonia

    Date

    August 10, 2019 10:46 AM PDT

    Photos / Sounds

    What

    Valley Spurge (Euphorbia ocellata ssp. ocellata)

    Observer

    leptonia

    Date

    August 10, 2019 10:21 AM PDT

    Photos / Sounds

    What

    Valley Spurge (Euphorbia ocellata ssp. ocellata)

    Observer

    leptonia

    Date

    August 10, 2019 10:20 AM PDT

    Photos / Sounds

    What

    Valley Spurge (Euphorbia ocellata ssp. ocellata)

    Observer

    leptonia

    Date

    August 10, 2019 10:20 AM PDT

    Photos / Sounds

    What

    Pincushion Plants (Genus Navarretia)

    Observer

    leptonia

    Date

    August 10, 2019 10:18 AM PDT

    Photos / Sounds

    What

    Valley Spurge (Euphorbia ocellata ssp. ocellata)

    Observer

    leptonia

    Date

    August 10, 2019 10:14 AM PDT

    Photos / Sounds

    What

    Water Clover (Marsilea vestita)

    Observer

    leptonia

    Date

    August 10, 2019 10:12 AM PDT

    Comments

    No comments yet.

    Add a Comment

    Sign In or Sign Up to add comments