This week’s tour is in Dogpatch, a neighborhood undergoing substantial changes, with historic homes and tech offices side-by-side. A benign climate encourages an array of interesting trees. The tour begins on the NW corner of Pennsylvania and 22nd Street, near the 22nd Street CalTrain Station. Our group is the same: Jason Dewees (author of Designing with Palms), Richard Turner (retired editor of Pacific Horticulture), and I’m Mike Sullivan, author of Trees of San Francisco.

The walk heads north on Pennsylvania Street to 20th Street, then east over the 20th Street bridge (for a short canopy walk) to Tennessee Street, north on Tennessee to 19th Street, west on 19th to Minnesota Street, north on Minnesota to 18th Street, west on 18th to Indiana Street, south on Indiana to 19th, east one block on 19th, then returns to Indiana, continues south on Indiana to 20th, and turns west on 20th. The final trees are on 20th between Indiana and the I-280 freeway overpass, about a block from the start of the tour.

Believe it or not, San Francisco’s only sugar maple (Acer saccharum) at the corner of 22nd and Pennsylvania — Believe it or not, San Francisco’s only sugar maple (*Acer saccharum*) at the corner of 22nd and Pennsylvania

Numbered trees are labeled with common and scientific names and country of origin, all written in white chalk on the sidewalk; accompanying numbers, in blue, run from 1 to 59. White arrows on the pavement provide directions whenever a turn is needed.

NW corner of Pennsylvania and 22nd streets,

1. 698 Pennsylvania Sugar maple (Acer saccharum), Great Lakes to Canada to Tennessee; appears on the Canadian flag; not well adapted to San Francisco’s climate, as evidenced by this tree’s general lack of vigor. This is the only sugar maple known to exist in San Francisco!

2. 1200 - 22nd Freeman maple (Acer x freemanii), hybrid of Acer rubrum & Acer accharinum, both from E North America (all of the maples surrounding this building are freeman maples (other than the sugar maple at the corner)

Pennsylvania Street, 22nd to 20th, east side

3. 699 Pennsylvania Sweetgum (Liquidambar styraciflua), E USA to Mexico & C America (several trees are on 22nd)

California buckeye (Aesculus californica) at the Caltrain station off of 22nd Street.

We didn’t “chalk” this, but you can see one of San Francisco’s “landmark trees” if you cross 22nd Street at this point, and walk down the stairs to the Caltrain stop. When you reach the bottom of the stairs, continue walking forward (away from 22nd Street) until you see a very large tree on the hillside on your right. The tree is a California buckeye (Aesculus californica), a tree that is native to San Francisco. This massive tree has been given landmark status by the City of San Francisco.

4. 681 Pennsylvania Red maple (Acer rubrum), Florida to Canada to Mississippi River

5. 603 Pennsylvania New Zealand Christmas tree, pōhutukawa (Metrosideros excelsa), New Zealand

602 Pennsylvania Primrose tree (Lagunaria patersonii), Australia & S Pacific Islands (across the street)

6. 587 Pennsylvania Australian willow (Geijera parviflora), E & SE Australia

7. 581 Pennsylvania Brazilian pepper tree (Schinus terebinthifolius), Brazil

8. 535 Pennsylvania Oleander (Nerium oleander), Mediterranean Basin to S China

Pennsylvania Street, north of 20th, east side

9. 491 Pennsylvania Jujube (Ziziphus jujube), S Asia to China; only one in San Francisco; fruits are edible and tasty

red ironbark (Eucalyptus sideroxylon) - one of San Francisco’s best of this species at 461-73 Pennsylvania

10. 461-473 Pennsylvania Red ironbark (Eucalyptus sideroxylon), E & SE Australia

11. 460 Pennsylvania Giant bird-of-paradise (Strelitzia nicolai), S Africa (across the street; banana-like foliage above the street address)

Return to and cross 20th Street, then turn left toward the Bay to cross the 20th Street bridge over I-280, Indiana, and Minnesota

Here we begin a “canopy walk” with chalked labels written on the bridge’s cylindrical handrail.

20th Street Bridge, Pennsylvania to Tennessee, south side

12. Over I-280, east side Silver dollar gum (Eucalyptus polyanthemos), SE Australia; the juvenile foliage on young trees looks like a silver dollar

13. Over Indiana, east side Dawn redwood (Metasequoia glyptostroboides), China; note the differences in character of these trees just south of the bridge with their relatives, the California coast redwoods further down the block

We had to get creative on this stretch of 20th Street…

14. Over Minnesota, west side Chinese elm (Ulmus parvifolia), E Asia

15. Over Minnesota, east side London plane tree (Platanus x acerifolia), hybrid of E USA species and European species; this commonly planted urban tree is prone to fungal diseases in SF’s cool foggy climate, as evidenced by the disfigured leaves and shoot tips on this tree

Back on terra firma…

Tennessee Street, 20th to 19th, west side

16. 888 Tennessee Purple-leaf plum (Prunus cerasifera), Eurasia (formerly SF’s most planted street tree)

17. 800 Tennessee Locust (Robinia x ambigua ‘Idahoensis’), hybrid of N American species

19th Street, Tennessee to Minnesota, south side

18. Entire block Brisbane box (Lophostemon confertus), E Australia

Here, we begin a tour of UCSF’s “Medicinal/Botanical Garden,” created by the landscape firm of Delaney + Chin. The garden wraps around east, west, and south sides of 654 Minnesota, beginning here with Minnesota Street. After rounding the block in a counterclockwise direction, we return to the garden on Indiana and 22nd streets.

Minnesota Street, 19th to 18th, west side

19. 654 Minnesota Japanese maple (Acer palmatum), Korea & Japan

19 ½. 654 Minnesota Italian bay tree (Laurus nobilis), Mediterranean Basin; leaves used for seasoning

20. 654 Minnesota Ginkgo (Ginkgo biloba), China; fruits of the female trees are foul-smelling but the seeds are considered a delicacy in China and Japan [delicious!: editor]

21. 660 Minnesota Chinese elm (Ulmus parvifolia), E Asia

Turn left onto 18th Street and walk to Indiana Street

Indiana Street, 18th to 19th, east side

22. North half of block Fern-leaf Catalina ironwood (Lyanothamnus floribundus ssp. asplenifolius), CA’s Channel Islands, except Catalina; CA native

23. (not used)

24. 654 Minnesota Cabbage tree (Cussonia paniculata), S Africa

25. 654 Minnesota Edible fig tree (Ficus carica), E Mediterranean Basin to C Asia; trained against the wall as an espalier

26. 680 Indiana African sumac (Rhus lancea), S Africa (across the street)

27. 654 Minnesota Guava (Psidium guajava), Mexico to C America and Caribbean

28. 654 Minnesota Macadamia nut tree (Macadamia sp.), Australia

29. Indiana at end of 19th Cottonwood or poplar (Populus sp.), N America (across the street)

19th Street, Indiana to Minnesota, north side

30. 654 Minnesota Peach tree (Prunus persica), China

31. 654 Minnesota Lime tree (Citrus x aurantifolia x Citrus limon), hybrid origin

32. 654 Minnesota Loquat (Rhaphiolepis loquata, syn. Eriobotrya japonica), SE China; fruit is edible

Pomegranate (Punica granatum), SW Asia

33. 654 Minnesota Makrut lime (Citrus hystrix), SE Asia

34. 654 Minnesota Calamondin/calamansi (xCitrofortunella microcarpa), hybrid of mandarin and kumquat

Return to Indiana Street and head south along the west side of Esprit Park.

Indiana Street, 19th to 20th, east side

35. Esprit Park Purple smoke tree (Cotinus coggygria ‘Royal Purple’), Eurasia; low tree with purple foliage, inside the park

36. Esprit Park Coast redwood (Sequoia sempervirens), C & N CA coastal native, tallest tree species in the world (most of the coniferous trees along the west edge of the park)

37. Esprit Park Pacific wax myrtle (Myrica californica), CA to British Columbia (two large shrubs along the sidewalk)

38. Esprit Park Monterey pine (Pinus radiata), Año Nuevo, Monterey, Cambria, CA native, most widely planted coniferous tree in the world (mostly for lumber)

Indiana Street, 20th to 22nd, east side

9. 801 Indiana Dawn redwood (Metasequoia glyptostroboides), China, thought extinct but discovered in the 1940s (previously seen from the canopy walk on the 20th Street bridge overhead)

40. 867 Indiana Victorian box (Pittosporum undulatum) E Australia (a few trees among a grove of large coast redwoods)

41. 953 Indiana London plane tree (Platanus x acerifoliia), hybrid of E USA species and European species

22nd Street, Indiana to I-280 overpass, north side

42. 998 Indiana Ginkgo (Ginkgo biloba), China; note the slightly different character of the foliage on this selection of ginkgo (trees are on 22nd)

43. 998 Indiana Red maple (Acer rubrum), Florida to Canada to Mississippi River (trees are on 22nd)

This walking tour of was organized by Mike Sullivan, author of The Trees of San Francisco (if you like this tour, there are 12 more neighborhood tree tours in Mike’s book), Jason Dewees, horticulturist at Flora Grubb Gardens and author of Designing with Palms; and Richard Turner, retired editor of Pacific Horticulture magazine and editor of Trees of Golden Gate Park. If you’re a tree enthusiast, buy all three books! You can follow Mike (@sftreeguy) and Jason (@loulufan) on Instagram.