Oriental sweet gum
The deciduous leaves are finely toothed, as with American sweet gum, but there is a strong tendency for the lobes to possess minor lobes. A row that was planted in 1957 on Santa Fe Avenue off Mayfield Avenue offered the opportunity of comparison with three American sweet gums that inadvertently got mixed in, probably from stock that was planted on nearby Esplanada Way. As an indication of sensitivity to frost, all the Santa Fe specimens died in the freeze of December 1972. The inner bark yields a fragrant resin known to the Greeks in antiquity as sturax and to us as storax. There are several trees that could have been the source of storax in the olden days, but today it is prepared from liquidambars.
Leaf shape alone gives a clue to identity, but there is a time in March–April when all the Oriental sweet gums are in full leaf and the natives are quite bare. There is also a difference in fall color. At first glance it is possible to mistake a sweet gum for a maple especially if no seed balls are in evidence. However, one can tell from the leaves, which are alternate, have two tiny stipule scars at the base of the stalk, and have a small gland on each tooth.
Two specimens that grew on the south side of Ginzton Laboratory had appeared to be in good condition and had flowered and set fruit. They are now gone, victims of frost or perhaps construction of the Gravity Probe-B building. No other specimens are known on campus.
About this Entry: The main text of this entry is from the book Trees of Stanford and Environs, by Ronald Bracewell, published 2005. A bit more information about the Ginzton Lab specimens added, from the 1984 version of Trees on the Stanford Campus (Oct 2017, SP).