Gaps in Eastern US Oak Gall-Host Relationships
If anyone wants to contribute to our knowledge of galls in the eastern US, one area would be to take a look at some of the less (or un) documented host species (shoutout to @ericanewman who is looking at some of the Texas species). If you have a local patch of any of these oak species, it would be valuable to go out and see if you can find any galls on them. Given the host specificity of some gall species, you might even find something new to science. If anyone is willing to share any sites where any of these species are common (most likely place to find galls), feel free to send me a DM as I am going to try and hunt for some of these next year (Florida in the spring and somewhere in the AL/MS/AR/LA range in summer).
Underdocumented host list:
- Quotes below from the Flora of North America (FNA)
- For known gall species lists see www.gallformers.org and search for the host.
- Gall # below are as of the date of this post and include gall-like scales and known but undescribed species.
Quercus acerifolia
AR, according to @destes on this observation (https://www.inaturalist.org/observations/12424063) locally common on the Cumberland Plateau of SE TN, as well as NW GA and NE AL.
"Dry glades, slopes, and ridge tops"
No documented gall species.
Quercus arkansana
AL AR FL GA LA MS TX
"An understory tree of well-drained, sandy soils, on ravine heads (pocosins, steepheads)"
No documented gall species.
Quercus austrina
AL FL GA MS NC SC
"River bottoms, wet forests, flatwoods"
1 documented gall species.
Quercus boyntonii
AL TX
"Deep sands and crevices in pine forests, along streams"
Probably similar/same gall fauna as Q. stellata.
No documented gall species.
Quercus ellipsoidalis
IL IN IA MI MN MO ND OH WI ON
"Dry sandy sites, rarely on moderately mesic slopes or uplands"
Looks to be common in upper midwest. Underdocumented bc it can be confused with other oak species. Would be particularly interesting to look at sites where closely related oaks are less common (Maybe N. Minnesota?)
I am not confident that any of the Ohio records for this species are real.
8 documented gall species.
Quercus georgiana
AL GA NC SC
"Granitic outcrops and dry slopes and knolls"
4 documented gall species.
Quercus havardii
AZ CO KS NM OK TX UT
"Deep, shifting or stabilized sand dunes, off deep sands in putative hybrid populations"
Looks to be fairly common on the high plains of W. Texas and Oklahoma, maybe along the caprock escarpment as well.
7 documented gall species. Good potential for unique species.
Quercus hemisphaerica
AL AR FL GA LA MD MS NC PA SC TX VA
"Moderately dry sandy soils, scrub sandhills, stream banks, occasionally on hillsides and ravines."
Lack of documentation likely due to the taxonomic confusion between this and Q. laurifolia. Should be fairly easy to ID based on site location. Fairly common in the SE.
11 documented gall species.
Quercus inopina
FL
"On deep white "sugar" sands of low sandhill ridges, scrub communities, and flat upland terraces"
Looks to be fairly common in FL. Target for spring trip.
12 documented gall species.
Quercus laceyi
TX
"Limestone hills, woodlands and riparian forests, canyons and streamsides"
Looks to be fairly common in Texas hill country.
12 documented gall species.
Quercus minima
AL FL GA LA MS NC SC
"Coastal plain, open evergreen woodlands and scrublands on deep sandy soils, often as understory with pines"
Looks to be common in Florida. Spring trip target.
12 documented gall species.
Quercus mohriana
NM OK TX
"Limestone hills and slopes, calcareous substrates"
Fairly common in W. - W/C Texas.
2 documented gall species. Great potential for unique species.
Quercus muehlenbergii
AL AR CT FL GA IL IN IA KS KY LA MD MA MI MN MS MO NE NJ NM NY NC OH OK PA SC TN TX VT VA WV WI ON
"Mixed deciduous forest, woodlands and thickets, sometimes restricted to n slopes and riparian habitats in w parts of range, limestone and calcareous soils, rarely on other substrates"
Common in W Ohio and on marblehead Penninsula. According to iNat map fairly common in the Midwest US. Isolated western populations would be interesting to survey (NM, OK, TX) to see if they have any species that the eastern populations lack.
18 documented gall species, probably too high to be on this list, but lacking in the literature and so the more eyes the better.
Quercus oglethorpensis
AL GA LA MS SC
"Alluvial flatwoods and streamsides in rich woods, low pastures, and edge of bottomland forests"
FNA says "locally common in GA and SC"
No documented gall species.
Quercus pumila (frmr elliottii)
AL FL GA MS NC SC
" Dry sandy soils of savannahs, low ridges and oak-pine scrub, occasionally at margins of poorly drained sites"
Looks to be fairly common in Fl, a target for my spring trip.
5 documented gall species
Quercus shumardii
AL AR FL GA IL IN KS KY LA MD MI MS MO NY NC OH OK PA SC TN TX VA WV ON
"Mesic slopes and bottoms, stream banks and poorly drained uplands"
According to the iNat map, most common in TX. Poor documentation is likely to do with how easy it is to confuse with other red oaks.
9 documented gall species.
Quercus texana (frmr nuttalli)
AL AR IL KS KY LA MS MO OK TN TX
"Flood plains and bottomlands"
Looking at the iNat map looks to be fairly common in the Mississippi river delta (particularly LA) and the Houston Metro.
2 documented species
.
Quercus vaseyana
TX
"Dry limestone slopes, oak and mesquite woodlands, juniper woodlands, and canyons and ravines in otherwise dry, open grasslands, sometimes descending into margins of dry scrub"
As I understand it is fairly common in the Texas Hill country. High potential for interesting stuff.
No documented gall species on this host.
In addition to the list above we could use more eyes on Quercus incana and Quercus lyrata as well, even though they are fairly well documented.