I’ve been reading the book “Oaks of California” by Bruce M. Pavlik et al, and in it they mentioned that a good place to find a variety of oak trees was the Peter J. Shields Oak Grove in the Davis Arboretum.  I’d never been there before, but my friend and fellow naturalist Roxanne kind of knew where it was, so she handled the driving and I did the navigation piece. 

I really despise driving in Davis. I don’t know who, if anyone, designed that place, but it’s a fricking mess.  A maze of too-narrow roadways, unmarked streets, streets in loops (so you pass the same street name about three times), traffic circles, no places to park, delivery trucks and buses that clog the right of way, and bicyclists who refuse to obey the rules of the road.  Hate it, hate it, hate it.  We weren’t on any specific time constraint, though, so Roxanne was patient with the mess and got us to our destination.

Thankfully, the oak grove was worth getting too.  At the entrance there’s a hug wall of mosaic piece showing a variety of different species of flowers, plants, trees, insects and birds… and some of the donors’ beloved pets. (On tile had a Corgi on it. Hah!) There were similar mosaic art pieces up along all of the outer walls of the restroom facility, and several markers and benches throughout the grove. 

The grove itself was an easy, leisurely walk through adult,, well-maintained trees, some of which were 30 to 60 feet tall.  As soon as we got out of the car, we were greeted by stands of Valley Oaks, and checked them out for galls.  I was actually kind of hoping to find a Black Oak and Engelmann Oak in the grove to see if they had any galls on them that we hadn’t seen before… but we somehow missed those trees among the forest. 

We DID see a LOT of different oaks, however, from all over the world.  So many, if fact, that after a couple of hours my brain couldn’t hold anymore information, and they all started to look the same.  There was also a stand of hybrid trees that made Roxanne and I wonder if the University had done the interbreeding itself to study how the trees fared.  Along with the Valley Oak, I counted about 38 different species (including the hybrids). Wow.  And these were just the ones I’d gotten photos of:

• Anatolian Oak Hybrid, Quercus petraea ssp. iberica x Quercus robur [Sessile Oak x Cypress Oak]
• Boissier Oak, Aleppo oak, Quercus infectoria ssp. venens
• Brandegee Oak, Quercus brandegeei
• Bur Oak, Quercus macrocarpa
• California Scrub Oak, Quercus berberidifolia
• Camay Oak, Quercus obtusata
• Chinkapin Oak, Quercus muehlenbergii
• Coast Live Oak, Quercus agrifolia
• Cork Oak, Quercus suber
• Cozahautl Oak, Quercus mexicana
• Cypress Oak f. fasigiata, Quercus robur
• Downy Oak, Quercus pubescens
• Durand Oak, Bastard Oak, Quercus sinuate
• Encino Blanco, Quercus candicans [This one has a natural resistance to honey fungus]
• Encino de Chalma Oak, Quercus diversifolia
• Encino Hojarasco, Quercus crassifolia
• Encino Tesmolillo Oak, Quercus crassipes
• English Oak, Quercus rober
• Gambel Oak, Quercus gambelii
• Gregg Oak, Quercus greggii
• Holly Oak, Holm Oak, Quercus ilex [This is the one under which truffles usually grow]
• Hybrid Oak: Quercus gambelii x Quercus mongolica [Gambel Oak x Mongolia Oak]
• Hybrid Oak: Quercus gambelii x Quercus sp. [Gambel Oak x Unidentified white oak]
• Hybrid Oak: Quercus macrocarpa x Quercus gambelii [Bur Oak x Gambel Oak]
• Hybrid Oak: Quercus macrocarpa x Quercus lobata [Bur Oak x Valley Oak]
• Hybrid Oak: Quercus robur x Quercus macrocarpa [Cypress Oak x Bur Oak]
• Hybrid Oak: Quercus turbinella x Quercus virginiana [Turbinella Oak x Southern Live Oak]
• Island Oak, Quercus tomentella
• Japanese Live Oak, Bamboo-Leaf Oak, Quercus myrsinifolia
• Macedonia Oak, Quercus trojana
• Oak of Tabor, Quercus ithaburensis
• Oracle Oak, Quercus x morehus
• Persian Oak Hybrid, Quercus castanelfolia x Quercus cerris [Chestnut-Leaved Oak x Turkish Oak]
• Sand Post Oak, Dwarf Sand Post, Quercus margarettea
• Southern Coast Live Oak, Quercus agrifolia var. oxyadenia
• Turkish Oak, Quercus cerris
• Ubamegashi Oak, Quercus phillyreoides
• White Oak, Quercus alba

CLICK HERE for the album of oak trees.
CLICK HERE for the album of other photos from today.
CLICK HERE for a video of one of the mosaic benches in the grove.

On the backside of the leaves of one of the non-native oaks, along the midline, we found some small dust-bunny like galls growing.  They were fuzzy, like Yellow Wig galls, but with shorter hairs, a more rounded body, and a paler blond color.  I believe it was on the Brandegee Oak, Quercus brandegeei, and think it might be the gall of the Woolly Leaf Gall wasp, Andricus quercuslanigera.  They form on white oaks in California, and even though the Brandegee isn’t a native here, it IS in the white oak lineage.  There was also the Woolly Oak Gall, Callirhytis lanata, but it’s usually found on red oaks on the east coast…  So, I’m going with Andricus quercuslanigera.

We also came across another great example of “fasciation” on a Silver Texas Mountain Laurel shrub, Sophora secundiflora.  Some of the flowering panicles had merged together to form these interesting-looking curling “paddles”. 

The shrub has long clusters of bluish-purple flowers (almost like wisteria).  Some sources say they smell like grape Kool-Aid.  They were also showing off a lot of their woody seed pods that rattle like castanets (and are filled with red, glossy poisonous seeds).  It’s not native to California but grows here, although it’s generally a slow grower. Very neat plant.

Another non-oak standout was a small grouping of Red Spider Lilies, Lycoris radiata.  They look just like their name describes – large bright reddish-orange spiders on stalks. 

And we found a passionflower vine that had fruit on it.  I’d seen them with flowers before, but never with fruit, so that was a first for me.

About a month or so ago I was jazzed about finding and identifying a beetle I hadn’t seen before, the Three-lined Potato Beetle, Lema daturaphila. I thought it had such lovely markings… Today, I found them again on the flowers and leaves of several Jimson Weed plants, some of them singles, but lots of others in pairs doing their bug-porn thing. The males are smaller than the females, so they really have to stretch to make a connection. But… then I saw the babies. They were totally decimating every part of the plant they could get their baby teeth on… and… Eeeeew! Seriously?! Those little guys are disgusting! They’re slimy and look like little slugs with feet, and they apparently have an apparatus on their back that allows them to poop all over themselves to disguise their fat larva-bodies from predators. Nature is cool and totally gross sometimes. Hah!

I noticed on some of the trees that their plastic identification cards were mounted on wire strings or spring-mounts that would allow the tree to grow while still keeping the card where it needed to be.  On one tree, though, we saw that the tree had actually overgrown the card and a new car had to be mounted elsewhere on it.

We walked for about 3½ hours and then headed out again. On our way out, we caught sight of a Monarch butterfly flitting across the grass.  She wouldn’t stand still long enough for us to get any good photos of her, but I did get a distant one of her when she landed briefly on a Jimson Weed flower.

Species List:

1. Afghan Redbud, Cercis griffithii
2. Anatolian Oak Hybrid, Quercus petraea ssp. iberica x Quercus robur [Sessile Oak x Cypress Oak]
3. Aster, European Michaelmas-Daisy, “Purple Dome”, Aster amellus
4. Autumn Sage, Salvia greggii
5. Boissier Oak, Quercus infectoria ssp. venens
6. Brandegee Oak, Quercus brandegeei
7. Bur Oak, Quercus macrocarpa
8. California Ground Squirrel, Otospermophilus beecheyi
9. California Scrub Oak, Quercus berberidifolia
10. Cascade Creek California Goldenrod, Solidago californica
11. Camay Oak, Quercus obtusata
12. Chilean Lily-of-the-Valley Tree, Crinodendron patagua
13. Chinkapin Oak, Quercus muehlenbergii
14. Coast Live Oak, Quercus agrifolia
15. Convoluted Gall Wasp, Andricus confertus
16. Cork Oak, Quercus suber
17. Cozahautl Oak, Quercus mexicana
18. Crepe Myrtle Hybrid, Lagerstroemia hybrid
19. Cypress Oak f. fasigiata, Quercus robur
20. Cyprus Cyclamen, Cyclamen cyprium
21. Downy Oak, Quercus pubescens
22. Durand Oak, Bastard Oak, Quercus sinuate
23. Eastern Fox Squirrel, Sciurus niger
24. Eastern Prickly Pear, Oputia compressa
25. Encino blanco, Quercus candicans
26. Encino de Chalma Oak, Quercus diversifolia
27. Encino hojarasco, Quercus, crassifolia
28. Encino Tesmolillo Oak, Quercus crassipes
29. English Oak, Quercus rober
30. Gambel Oak, Quercus gambelii
31. Gregg Oak, Quercus greggii
32. Holly Oak, Holm Oak, Quercus ilex
33. Hybrid Oak: Quercus gambelii x Quercus mongolica [Gambel Oak x Mongolia Oak]
34. Hybrid Oak: Quercus gambelii x Quercus sp. [Gambel Oak x Unidentified white oak]
35. Hybrid Oak: Quercus macrocarpa x Quercus gambelii [Bur Oak x Gambel Oak]
36. Hybrid Oak: Quercus macrocarpa x Quercus lobata [Bur Oak x Valley Oak]
37. Hybrid Oak: Quercus robur x Quercus macrocarpa [Cypress Oak x Bur Oak]
38. Hybrid Oak: Quercus turbinella x Quercus virginiana [Turbinella Oak x Southern Live Oak]
39. Indian Blanket Flower, Gaillardia pulchella
40. Irregular Spindle Gall Wasp, Andricus chrysolepidicola
41. Island Oak, Quercus tomentella
42. Japanese Live Oak, Bamboo-Leaf Oak, Quercus myrsinifolia
43. Jimson Weed, Datura stramonium
44. Jumping Oak Gall Wasp, Neuroterus saltatorius
45. Live Oak Gall Wasp, 1st Generation, Callirhytis quercuspomiformis
46. Macedonia Oak, Quercus trojana
47. Monarch Butterfly, Danaus plexippus
48. Naked Lady Lily, Amaryllis Belladonna
49. Oak Apple Gall Wasp, Andricus quercuscalifornicus
50. Oak of Tabor, Quercus ithaburensis
51. Oracle Oak, Quercus x morehus
52. Passionflower ‘Betty Myles Young’, Passiflora hybrid (flower and fruit)
53. Persian Oak Hybrid, Quercus castanelfolia x Quercus cerris [Chestnut-Leaved Oak x Turkish Oak]
54. Pleated Ink Cap Mushroom, Parasola plicatilis
55. Pumpkin Gall Wasp, Dryocosmus minusculus
56. Purple Sage, Silverleaf, Cenzio, Leucophyllum frutescens
57. Red Cone Gall Wasp, Andricus kingi
58. Red Coral Fountain, “St. Elmo’s Fire”, Russelia equisetiformis
59. Red Spider Lily, Lycoris radiata
60. Ribbed Cocoon-Maker Moth, Bucculatrix albertiella
61. Sand Post Oak, Dwarf Sand Post, Quercus margarettea
62. Silver Texas Mountain Laurel, Sophora secundiflora [fasciation]
63. Southern Coast Live Oak, Quercus agrifolia var. oxyadenia
64. Three-lined Potato Beetle, Lema daturaphila
65. Turkish Oak, Quercus cerris
66. Ubamegashi Oak, Quercus phillyreoides
67. Valley Carpenter Bee, Xylocopa varipuncta
68. Valley Oak, Quercus lobata
69. Variegated Agave, Agave americana
70. Western Bluebird, Sialia mexicana
71. Western Spotted Orbweaver Spider, Neoscona oaxacensis
72. White Crepe Myrtle, Natchez Crepe Myrtle, Lagerstroemia x ‘Natchez’
73. White Oak, Quercus alba
74. Winter Daffodil, Sternbergia lutea
75. Woolly Leaf Gall Wasp, Andricus quercuslanigera
76. Yellow Wig Gall Wasp, Andricus fullawayi