37. Horse Chestnut

Specimen Size: 65.4ft tall, 24in in diameter.

Location: Lining Skagit Lane South of the Music Building

Historical Background: The name "Horse Chestnut" was probably given originally because the fruits were used by the Turks as a drug for horses suffering from broken wind or coughs. The seeds were used in France and Switzerland for whitening hemp, flax, silk, and wool and can also dye fabrics a sky-blue color. The conkers placed in the corners of a room are rumored to keep spiders away, but this use is still debated. The flowers contain quercetin, a dye and an antihistamine. The wood is soft, light, but not durable enough to be used commercially. 

Non-Native

Native Range: Mountains of Greece and Balkan peninsula

Identifying Features: This tree is NOT a true chestnut (in other words do not eat their fruit), however, if you have children looking for small hard projectiles with which to make mischief, these are the trees of choice. They produce chestnut-like hard brown fruits called buckeyes, with a white patch on them, wrapped in a greenish to whitish prickly skin. These may be found littering the ground under them in fall or landing upon oneself as one strolls beneath them. The leaves are beautiful, with 5-7 leaflets stemming from a single base stem, oblong and bulbous at the tip before coming to an abrupt pointy tip. Each are unevenly serrated and are of a bright green color. The flowers are also very distinctive, and appear in spring as massive tall erect bunches of white and pink in a colicle shape with up to 150 small flowers per erect shoot. Bark is a mottled gray and generally smooth but developing scaly fissures with age.

Identifying Features In Depth:

1. Form: A tall deciduous broadleaf with a rounded and sweeping dense crown rising up to 130’ (40m). Branches are upswept, pointing skyward and sometimes layering.

2. Leaves: Leaves are opposite and palmately compound, composed of 5-7 leaflets which are obovate, or elliptical with the broadest point near the tip before ending in an abrupt point, They taper to a stalkless base and are sawtoothed on the margins and 4-10” (10-25cm) in length (with each leaflet on the leaf varying in size somewhat with the smallest on the edges of the palmate formation). They are a dull dark green above and pale green below. Leafstalks are long, 3-7” (7.5-18cm) long.

3. Bark: Gray to brown, thin and smooth and becoming more scaly and fissured with age. Twigs are light brown and hairless and often end in a large sticky bud.

4. Reproductive Bodies: Flowering structures are impressive, clustered in tall (up to a foot or more) conical stands of 1” (2.5cm) long bell shaped flowers with narrow white petals with yellow and pink spots. These give way to the buckeye fruit, 2-2.5” (5-6cm) in diameter, round and hard and dark shiny brown encapsulated in a soft spiny capsule of green to tan color with 1-2 seeds each. They mature in late summer and are poisonous. This tree is a common feature along Seattle’s streets.