Favoritos de mertensia

This single plant was the target of our quest today. And finding it was extremely...EXTREMELY surprising. This plant (i.e. a stem from apparently the same underground rhizome) was first discovered in about 1984 by me. At the time, I tentatively identified it as Trillium gracile, a species of southeast Texas and eastward. The ID has been debated and the remarkable occurrence of the plant at this location is very curious (long story). I had rechecked this plant probably 15 years ago and it was still present, and now--some 35 years after its first discovery, it is still putting up a flower in a lonely attempt to propagate. (There is, and has always only been, just the one plant here.) All of us, including eminent botanist Bill Carr (4th image) and Dr. George Yatskievych (U.T. Herbarium, 5th image, kneeling to photograph the plant) were just floored that we could refind the plant.

The plant is found in a mesic shaded canyon head at a permanent spring. The plant is in moist silty loam at the base of a bluff adjacent to the springhead pool, with abundant leaf litter, under mature oak-ash-elm-juniper woodland. Aside from a wealth of recent invasives (Japanese Honeysuckle, Glossy Privet, etc.), the site includes several relictual species of very local occurrence in Travis County, including:
-- Spicebush (Lindera benzoin)
-- Cross Vine (Bignonia capreolata)
-- Bristly Greenbrier (Smilax tamnoides [= S. hispida])
-- Eastern Columbine (Aquilegia canadensis)

No kidding.

@joegiulian and @samwilhelm first observed and collected small Colletes males hovering around a patch of Kalmia angustifolia at this open, sandy site in the Pinelands during the last week of May. C. bradleyi had been on our radar, but this was somewhat earlier than we expected since previous records are from mid-late June. The male of C. bradleyi was formerly unknown, but it seemed to us that multiple features of these male specimens (fine, well-spaced punctures on scutum, carinate metapleural projection with testaceous rim) were reminiscent of descriptions of the female of C. bradleyi by Mitchell (1951) and Stephen (1954). The following day, @andrew_aldercotte and I visited the same site and observed multiple male Colletes, as well as females that appeared to be collecting pollen from Kalmia angustifolia (see photo). Male specimens collected on this day matched those collected previously at the site by Joe and Sam and females we collected keyed exactly to C. bradleyi following Mitchell (1951) and Stephen (1954). Highly distinctive in the field - overall impression much like other americanus-group Colletes, but somewhat duller and lacking basal hair bands on tergites; quite unique among the Colletes and general bee fauna active in our area at this time of year. Subsequent visits to other sites in the Pinelands have turned up several more female and male specimens, all collected in association with Kalmia angustifolia (alongside Andrena kalmiae and occasionally Colletes consors!). Full natural history writeup in the works...

A specimen recently discovered by Joe that was taken in Washington County, Maine, provides the first evidence that this species may occur more widely than previously thought. Moral of the story for beewatchers in the northeast US: scrutinize flowering Sheep Laurel, especially in sandy barrens habitats!

Perhaps even more interestingly, Joe and Sam also managed to collect several male specimens of an as-of-yet unidentified Epeolus visiting Kalmia alongside Colletes bradleyi at our "original" site on the date that they first observed C. bradleyi males; we have yet to find additional individuals of this Epeolus despite effort.

See observation of male here: https://www.inaturalist.org/observations/122250341
See observations of Epeolus here:
https://www.inaturalist.org/observations/122250342
and here:
https://www.inaturalist.org/observations/122250345

Additional DSLR photos of specimens tba