Xanthoceras seed

Yellowhorn is an ornamental deciduous, flowering tree or multi-stemmed shrub that grows up to 20 to 25 feet tall.  A native of china, it is prized for its wonderful flowers, and elegant bright green foliage. It unites foliage recalling mountain ash (Sorbus), flowers like a horse chestnut tree and nuts like a macadamia. It is attractive, admirably cold hardy, drought tolerant, and generally tough. Remarkably, its leaves, flowers, and seeds are all edible. But it remains undeservedly rare and little known.
 
Yellowhorn features lustrous, rather finely pinnate dark green and glossy leaves 5 to 12 inches long, with 9 to 17 sharply toothed leaflets turning yellow in the fall. It has an upright habit, though the branches are spreading. The flowers are the chief glory of this tree. They are produced on the previous year's wood as the leaves unfold. The flowers are 5 petaled, 1 inch diameter, star-shaped and are mildly fragrant. Borne in racemes (clusters) 6 to 10 inch tall and begin life nearly white with a yellow eye that age to a deep pink after pollination. The entire plant almost disappears under the heavy bloom in May. The autumn fruit is an oval-shaped husk or capsule up to 2.5 inches, resembling a fig or buckeye husk, containing a dozen or so, edible, black, half-inch seeds. It splits into three sections when ripe. It is prudent to pick them before they fully open, thus preventing the nuts from falling out when harvesting. It is said that they taste like macadamia nuts.