Yellow Buckeye - Aesculus lutea, (octandra)

Aesculus is from the Latin esca meaning nourishment, referring to the flour that was ground from the kernels of some species; lutea means yellow. Early settlers thought the seed of the yellow buckeye looked like the eye of a deer and thus nicknamed the tree “buckeye.” Indians roasted the nuts and then shelled, peeled, mashed and leached the meal in order to remove the poison from the seed. This left them with a highly nutritious meal.

The digital (finger-like) arrangement of the leaflets of this compound-leaved plant are a dead give away to the identity of buckeye and the related horse-chestnut. This species differs from the more common Ohio buckeye (Aesculus glabra), in the tall, columnar growth habit, flaky, grayish bark and smooth-skinned fruit. Both have showy, yellow spikes of flowers in May or June. Horse- chestnut is a broader tree with larger leaves, white flowers and glossy, sticky buds. In winter, the buckeye can be readily identified by the large, non-resinous bud at the tip of each branch. Where buds are found in pairs, there will be a circular scar between where the flower and later the fruit was attached.

This tree is striking in the fall with an orange to red color. It is a native of limestone outcroppings from western Pennsylvania, west to eastern Nebraska and south into Georgia.

Other Denver locations

Probably the best specimen in the city is near the Eugene Field House in Washington Park.

http://en.wikipedia.org/wiki/Yellow_buckeye