September Color Appears at the Washington Park Arboretum (Part II)
1) Acer diabolicum (Horned Maple)
- This maple is one of the least ornamental of the native maples of Japan.
- It is named for the tiny horn-like appendages between the winged seeds.
- Ours is growing beside the Japanese Garden parking lot.
2) Koelreuteria bipinnata
- Named after a German professor of botany, J.G. Koelreuter (1733-1806), it is impossible for English speakers to pronounce.
- K. bipinnata is blooming now, but the more common K. paniculata is bearing its conspicuous inflated seed pods.
- Both species are located opposite Arboretum Drive on Foster Island Road.
3) Pterocarya stenoptera (Chinese wingnut)
- The Latin name literally means “narrow-winged wingnut”.
- A relative of walnuts and hickories, it is growing near them in 29-2W along Azalea Way.
4) Pterostyrax hispida (Epaulette Tree)
- Long panicles of spring flowers become chains of bristly (hence “hispida”) seeds.
- Native to China and Japan.
- The best examples in the Arboretum are along the east fence (9 and 10-7E).
5) Vitex agnus-castus (Chaste Tree)
- A shrub native to Mediterranean regions and southwest and central Asia.
- The Vitex genus includes large tropical and sub-tropical timber trees.
- In the Arboretum, it is located just south of the Woodland Garden pond on Azalea Way. A
white form is 100 feet north.