TABLE ROCKS INOREGON-ABOTANICAL HIKELinda R. McMahanExtension Botanist and HorticulturistOregon State University, Yamhill Countylinda.firstname.lastname@example.org
Here I am atthe topThis is a hike I’vewanted to do for a longtime, and I got thechance this Novemberduring a visit to Medford,Oregon. In thebackground you can seeMedford and CentralPoint. Nearer the rocksis the Rogue River as itwinds its way throughthe valley. I climbed theUpper Table Rock. Yes,there are two, but thiswas the shorter hike, sohaving to drive home forseveral hoursafterwards, I choseaccordingly.
Can You Seemy CarWe are about 800 feetabove the valley floor. Mycar is a tiny speck in theparking lot located at about2 o’clock in the picture.According to anarticle(http://www.npsoregon.org/kalmiopsis/kalmiopsis03/seevers_borgias.pdf),the “tables” were createdby erosion. Originally lavaflows had filled in the basin,perhaps 9.6 million yearsago. Gradual erosionwashed away most of thesofter flow materials, butthe Table Rocks wereharder material calledandesite, and remained.
Lava FeaturesThe volcanic orgin wasevident everywhere,from the tumbled rocksmaking up the basearound the trail, to thisrock formation by thetrail.
Erosion is stillgoing onAt the inward edge ofUpper Table rock,breakup of the plateaustill occurs. Hugechunks of columnarandesite are slowlybreaking away. Eachplateau is in ahorseshoe shape. Theshape apparently wascaused by formermeanders in theUmpqua River.
Oregon WhiteOak, QuercusgarryanaBeing a botanist, I wasnaturally interested inthe vegetation. Actually,every hike for me turnsinto a botanicalexperience.Fall color for the oakswas very nice, at leastfor Oregon. Lichens andmosses were beginningto swell from the first bigrains of the fall season.Fortunately, the day’srain most held off untilafter I finished the hike.The ecosystem also hasthe California black oak(Quercus kellogii), but Ididn’t happen to snapany pictures of them toshare.
Mistletoe on oak,PhoradendronfavescensJust like oaks in theWillamette Valley to thenorth, Oregon white oak onthe reserve have lots ofmistletoe. Mistletoe is apartial parasite which isable to produce energythrough photosynthesis butneeds the tree to obtainother nutrients.The land on the two TableRocks has mostly beenpreserved by the Bureau ofLand Management (BLM)and The NatureConservancy. At one time,there were possible plansfor development, whichfortunately, nevermaterialized.
Poison oak,RhustoxicodendronA namesake of oak alsocaught my attention.There was plenty of it—the beautiful three-partleaves were gone,however. I onlyrecognized it by thecharacteristic stick-likegrowth form and theberries.
More poisonoakExcuse the fascinationfor a sometimestroubling native plant,but on the way up thetrail, I kept wonderingwhy there were stickscoming out of theground. On the waydown, I finally figured itout. Fortunately, I didn’tcheck it out too closely.
Madrone,ArbutusmenziesiiRecent rains brought outthe magnificent color ofmadrone bark. Olderbark peels off in layersas the tree grows. Manyof the madrones in thepreserve haverecovered after fires,which have periodicallyvisited the site for manygenerations of plants.
White-leafmanzanita,ArctostaphylosviscidaLarge manzanita shrubsdot the landscape, suchas this one under amadrone at the edge ofthe plateau. Theevergreen foliage isexcellent—I wish minewould grow like this, butI don’t have the gooddrainage and warmerclimate that they require.
Wedgeleafceanothus,CeanothuscuneatusA major component ofthis fire-maintainedecosystem, thewedgeleaf ceanothus isbeautiful much of theyear. Blooms arespectacular, but thosecome at another time ofyear—not in November!Guess I will just have toreturn.
View of the top!At the top of each TableRock, visitors aregreeted by a massiveflat area with a thincovering of soil that hasaccumulated over time.Fall vegetation is mostlygrasses, mostly alienones at that, but in thespring, it is apparently amuch different story—that’s when most peoplevisit who are interestedin the plants.The inset shows themoss, a major part ofthe plateau vegetation.
Vernal PoolsJust this view showsdifferent patterns ofvegetation. Indentationsin the surface allow theaccumulation of water inpools that dry up in thesummer. A successful ofcolorful flowers,sometimes in ringsaround the water, drawsvisitors in the springtime.The pools are fragileand becoming more rareas special areas likethese are disappearing.
From where I amstanding, you can seethe other end of thehorseshe shape forUpper Table Rock. Inthe distance is LowerTable Rock. Next time, Iwill come armed with theplant list and myidentification tools.