38 CityTREES
soils—but notably, it can also tolerate wet con-
ditions. It is a fast-growing species, putting on
as much as five feet (1.5 m) of shoot extension
per year. Providing supplemental watering in
drought summers until establishment is key.
The medium-maturing Chinese pistache/pistachio
(Pistachia chinensis) trees are doing well despite
drought pressure in San Antonio, according to
Holinsky. He says that Eve's necklace (Styphnolobium
affine) is "tried and true, if selected for good
form." The Texas ash (Fraxinus albicans) is faring
well, but Holinsky hesitates to plant more of
it—Emerald Ash Borer is on the horizon, tun-
neling away in counties in northeast Texas.
In the quest to build more diversity and resil-
ience in San Antonio's urban forest, Holinsky
and team are trialing the fortune empress tree
(Paulownia fortunei), a reportedly benign alter-
native to the highly invasive princess tree (P.
tomentosa). Honeylocust and black locust cul-
tivars are doing well, Holinsky says, as are tulip
tree (Liriodendron tulipifera) and cottonwood
(Populus deltoides), when sited appropriately.
"We've contracted with growers to provide us with
bigtooth maple (Acer grandidentatum), cloud forest
sugar maple (A. skutchii), Dura-Heat river birch
(Betula nigra), anacua tree (Ehretia anacua), and
various willow cultivars," Holinsky says. "We're even
trying out a chitalpa (× Chitalpa tashkentensis), which
is a catalpa crossed with a desert willow." (Fun fact:
a plant name is called "nothogeneric" when it com-
bines the genera of the parents. Chitalpa is a blend
of Chilopsis, from Chilopsis linearis, and Catalpa).
Illustration of Eve's necklace (Styphnolobium affine) foliage
and fruit by Lisa Travis, iNaturalist, CC BY-NC 4.0. The common
name implies something that could be readily broken, but Eve's
necklace is a super tough, soils-flexible, drought-tolerant species.
A chitalpa tree (× Chitalpa tashkentensis) showing flowers typical
of catalpas but the more narrow foliage associated with willows.
Photo by Frau Siebenschläfer, Wikimedia Commons, CC BY-SA 3.0
