#oligoneuron

It’s nowhere near the fall hayfever season, but I thought I’d PSA anyway.

Hayfever is caused by RAGWEED (Ambrosia artemisiifolia and Ambrosia trifida where I live).

NOT. Goldenrod (Solidago, Oligoneuron, Euthamia). It is impossible for goldenrods to even cause hayfever since their pollen isn’t released to the wind. Goldenrods are beautiful, with some edible parts, some medicinal properties, and middle of summer through fall pollenators love them.

Non-exhaustive list of goldenrods

Euthamia graminifolia (Flat-top goldenrod):

Oligoneuron rigida (Stiff goldenrod):

Solidago bicolor (Silverrod):

Solidago caesia (Blue-stem goldenrod):

Solidago canadensis (Canada goldenrod):

Solidago flexicaulis (Zigzag goldenrod):

Solidago juncea (Early goldenrod):

Solidago missouriensis (Prairie goldenrod):

Solidago multiradiata (Alpine goldenrod):

Solidago nemoralis (Gray goldenrod):

Solidago odora (Anise-scented goldenrod):

Solidago ohiensis (Ohio goldenrod):

Solidago patula (Rough-leaf goldenrod):

Solidago ptarmicoides (Upland white aster):

Solidago rugosa (Wrinkleleaf goldenrod):

Solidago simplex (Spike goldenrod):

Solidago speciosa (Showy goldenrod):

Solidago uliginosa (Bog goldenrod):

Oligoneuron rigidum

Stiff goldenrod, in a sand barren community, Red River Gorge, Kentucky

Nothing says late summer quite like the blooming of the goldenrods. These conspicuous members of the aster family get a bad rap because many folks blame them for causing hay fever. This is simply not true! In this video we take a closer look at a small handful of goldenrods as a way of celebrating this ecologically important group.

Music by: Artist: Ampacity 

Track: Encounter One 

William holding the stiff goldenrod rosette gall for a shot on a windy day.

Oligoneuron rigidum, or stiff goldenrod, is a bit of an outlier looking like this.

This is my first time seeing this species, a fairly tough and pubescent one, with this gull type. 

Rossette gall or bunch gulls are less common compared to the stem apple gulls and even rarer when it’s not on Solidago canadensis, S. giganteum, or S. altissima. 

The culprit that forms this gull on the usual species of Solidago is Rhopalomyia solidaginis, a small winter and spring active fly. The fly burrows into the meristem producing the leaf at a bud axis. The meristem tissue goes into a bit of shock and chemical signalling attempts to both continue meristemal growth while also layering parynchema ground tissue around the larva to the point that it becomes cut off from the plant. Swelling and the damage to the meristemal tissue during the early stages of plant growth means that plant hormones responsible for organ growth at the junction of interest are forced to produce more and work harder to fix the issue; however, the issue is not fixed in it’s normal sense, instead, a gall like tumor forms from swelling with multiple rosetting leaves.  the inside of the gall goes through a type of cell death that allows the inner most tissue to become calus with intermediate cells being involved with chemical stew production. The term for calving off the inside of a diseased section to prevent interaction with the pathogen or parasite by producing a gall, cyst, or tumor while utilizing calus is compartmentalization. 

The other common gulls found on the less rigid species of Solidago are the spindle ellipse gull caused by a Moth, Gnorimoschema gallaesolidaginis, and the round stem gull caused by the Goldenrod Gull fly,  Eurosta solidaginis.

If anyone would like to validate the species that may have caused this I would be stoked. I am currently under the assumption this is Rhopalomyia solidaginis. 

Still one of my favorite from Matt, Grant, and Sarah from @indefenseofplants