Paleoflora of the Eocene Okanagan Highlands

The highlands are a series of Early Eocene geological formations which span an 1,000 km (620 mi) transect of British Columbia, Canada and Washington state, United States and are known for the diverse and detailed plant fossils which represent an upland temperate ecosystem immediately after the Paleocene-Eocene thermal maximum, and before the increased cooling of the middle and late Eocene to Oligocene.

The noted richness of agricultural plant families in Republic and Princeton floras resulted in the term "Eocene orchards" being used for the paleofloras.

[3] The noted richness of Rosaceae fossils along with other important agricultural plant families found in the Republic and Princeton floras, including the genera that contain modern apples, blackberries, cherries, and serviceberries resulted in Wes Wher and Donald Hopkins (1994) coining the term "Eocene orchards".

[4][5] Fossil evidence from both Sorbus/Crataegus and Rhus leaves in the Republic sites indicate the area was a center for species overlap and active hybridization events.

However the certainty for the placement was later questioned by Archibald and Cannings (2022) who opted to tentatively exclude Quesnel from the highlands while discussing the history of field collecting in the region.

[12] The third algae is identified as a living paleoendemic Mallomonas species now restricted to warmer climates in North America and Europe.

Several fern specimens were briefly mentioned from Horsefly but no taxonomic assignment was made due to lack of reproductive vegetation.

[20] Alismataceae †Heleophyton †Heleophyton helobieoides[75] An aquatic or emergent water-plantain Amaryllidaceae †Paleoallium †Paleoallium billgenseli[76] An onion relative Aponogetonaceae Aponogeton †Aponogeton longispinosum[77] A Cape-pondweed pollen †Keratosperma †Keratosperma allenbyensis[78] An arum family member Orontium †Orontium wolfei[79] A golden club Arecaceae †Uhlia Uhlia allenbyensis[80] A Coryphoid palm Cyperaceae Carex Undescribed[36] Sedge fruitsNot described to species.

Iridaceae †Pararisteapollis †Pararisteapollis stockeyi[81] A possible iridaceous pollen morphotype †Ethela †Ethela sargentiana[82] A cyperaceous or juncaceous poalean monocot †Soleredera †Soleredera rhizomorpha[83] A lilialean genus of uncertain placement Menispermaceae Calycocarpum Undescribed[68] A moonseedNot described to species †Langeranthus †Langeranthus dillhoffiorum[84] A plane tree relative fruiting head.

Crataegus Undescribed[4][21] A hawthorn relativeNot described to speciesHorsefly specimens not mentioned by Pigg, Manchester, & DeVore (2023)[20] Cf.

[56] Acer dubium[60][36] single fruit missing a seed.Provisionally named by Penhallow (1902)Deemed nomen nudum by LaMotte (1952)[56]not mentioned by Pigg, Manchester, & DeVore (2023)[20] †Acer hillsi[111] A maple samara.

The first instance of ectomycorrhizae in the fossil record was reported by LePage et al. (1997) who documented mycorrhizal rootlets associated with Pinus roots.

Many late 1800's to early 1900's identifications of Okanagan highlands fossils were made based on geologic age assumptions ranging between the Miocene to Pliocene, and often specimens were grouped into species bins for taxa first described from Europe.

Alnus alaskana Newberry[36] Penhallow, 1908 Fragmentary leaves Type locality Kootznahoo islands, Alaska (Miocene?)

Alnus carpinoides Lesquereux[36] Penhallow, 1908 Fragmentary leaves Type locality Bridge Creek, Oregon (Miocene?)

Type locality Bridge Creek, Oregon Betula heterodonta Newberry[36] Penhallow, 1908 Leaves and one possible cone.

Type locality Bridge Creek, Oregon Betula macrophylla Göppert[36] Penhallow, 1908 Fragmetary leaves with cones.

Type locality Europe Betula stevensoni Lesquereux[60] Penhallow, 1902 Fragmentary leavesType locality Laramie, Wyoming Carpinus grandis Unger ex Heer Dawson, 1890 Corylus americana walt[36] Penhallow, 1908 A hazel nut †Cercidiphyllum arcticum[134][56] Dawson, 1879 A katsura leaf morphotypeMoved from Trochodendroides arctica (1926)[28] Also includes:[36][56] Jenkinsella arctica (Heer) Golovneva & Alekseev[28][135] Berry, 1926 A katsura like fruit morphospecies Moved from Leguminosites arachioides IncludesLeguminosites borealis, (illegitimate jr syn) †Cornophyllum nebrascensis (Schimper) McIver & Basinger[36][136] Penhallow, 1908 A punitive dogwood relativeFirst reported as "Cornus newberryi" †Cornus suborbifera Lesquereux?

†Quercus consimilis Newberry[36] Penhallow, 1908 Type locality Bridge Creek Flora, Oregon An oak leaf morphotype.

†Quercus dallii Lesquereux[36] Dawson, 1891 Type locality Cook Inlet, Alaska An oak leaf morphotype.

†Juglans occidentalis Newberry[36] Penhallow, 1908 Type locality Green River Formation, WyomingA walnut leaf morphospecies.

Ettingshausen Penhallow, 1908 Type locality Most Basin Bílina Czech RepublicA possible fig leaf morphospecies.

Ficus asiminaefolia Lesquereux Penhallow, 1908 Type locality "Rock Corral", CaliforniaA possible fig leaf morphospecies.

Ficus decandolleana Heer Penhallow, 1908 Type locality Monod, SwitzerlandA possible fig leaf morphospecies.

Ficus populina Heer Penhallow, 1908 Type locality Monod, SwitzerlandA possible fig leaf morphospecies.

Ficus ungeri Lesquereux Penhallow, 1908 Type locality Green River Formation, WhyomingA possible fig leaf morphospecies.

personata Knowlton[36] Penhallow, 1908 Type locality Fossil, OregonA bayberry species Onocleaceae †Onoclea hebridica (Forbes) Bell[36] Penhallow, 1908 Type locality Isle of Mull, UK A bead fern Listed as "Onoclea sensibilis" sensu Newberry Osmundaceae †Osmunda heeri Gaudin[36] Penhallow, 1908 Type locality Rivaz, Switzerland A royal fern Pinaceae †Pinus lardyana Heer[36] Penhallow, 1908 Type locality Switzerland A pine cone morphospecies †Phragmites alaskana Heer[28] Berry, 1926 A grass/sedge leaf morphogenus †Poacites tenuistriatus Heer[28] Berry, 1926 A grass/sedge leaf morphogenus Potamogetonaceae Potamogeton (?)

†Populus polymorpha Newberry[36] Penhallow, 1908 Type locality Bridge Creek, Oregon A cottonwood leaf morphotype.

[36] Penhallow, 1908 Type locality Admiralty Inlet, Alaska A grape leaf morphospeciesTentatively identified under the homonym Vitis rotundifolia (Newberry) †Vitis olriki Heer?

[36] Penhallow, 1908 Type locality Atanekerdluk, Greenland A grape leaf morphospeciesTentatively identified under the homonym Vitis rotundifolia (Newberry) †"Acer" grahamensis Knowlton & Cockerell[28] Berry, 1926 Type locality Port Graham, AlaskaFragmentary leaf fossils rejected from Acer by Wolfe & Tanai (1986)First identified as Acer macropterum (Heer) †Leguminosites arachioides Lesquereux[36] Penhallow, 1908 Type locality is Evanston, WyomingA fruit of uncertain family affinity