Greenhorn Mountains, off Sawmill Rd, Sequoia National Forest, Kern County, California, USA
May 31, 2012
Adding a 2nd image here (taken 5 sec before the other) in case it may help with ID...but also because it illustrates some interesting pollinator-adapted floral morphology.
If you're a
Phacelia connoisseur, you may have heard of "corolla scales" (described in the remarks with the 1st image in this series), which are usually present in species of
Phacelia (and some other genera of the former family Hydrophyllaceae, now subsumed into the Boraginaceae). A line-drawing detailing the corolla-scales of
P. exilis appears at the lower left of
Figure 4100 on pg. 506 of Abrams(1951).
In the above image, the bee is clutching a filament with its right fore-tarsi and sliding its mouthparts into the crevice between the two corolla scales associated with that stamen...which emanate from each side of the base of the filament and are fused to the corolla as they extend upward, together forming a pocket.
Corolla scales in
Phacelia vary in shape and attachment details among different species, and thus are sometimes used in keys and descriptions as distinguishing characters. Regarding this particular species,
Phacelia exilis, the detailed description on page 492 of
Howell includes the following:
"corolla-scales 1.5-2 mm. long, narrowly quadrate, truncate above, attached to corolla by one edge, the free edges of adjacent pairs connivent, at base more or less united to base of filaments and forming a shallow pocket"
Here "connivent" means the scales touch along their inner edges but are
not fused there. I believe what you can see in the image above is the dark black of the mouthparts of the bee, forcing the connivent scale edges apart slightly, as it initially thrusted its glossa into the pocket towards the nectary.