Pine nuts They are borne on the scales of pine cones, and like the coconut, are mainly endosperm tissue rather than cotyledons Like its cousins the pecan and hickories, the walnut is the stone of a thin-walled fruit, the edible portion being two lobed, wrinkled cotyledons Walnuts are exceptionally rich in the omega-3 polyunsaturated linolenic acid, which makes them nutritionally valuable but also especially liable to become rancid; they should be kept in the cold and dark The aroma of walnuts is created by a complex mixture of molecules derived from the oil (aldehydes, alcohols, and ketones) Walnut Relatives A North American relative of the Persian walnut, the black walnut (J nigra) is smaller, with a harder shell and a stronger, distinctive flavor It was once commonly used to make breads, confections, and ice creams, but it’s difficult to extract from the shell in large pieces and has been largely ignored Most still come from wild trees in Missouri Another American species, the butternut (J cinerea), is even less known, but remarkable for its high protein content — near 30% — and esteemed by enthusiasts as among the tastiest nuts The Japanese have an indigenous walnut, J ailantifolia, one of whose varieties is the distinctively heartshaped heartnut Characteristics of Other Oil-Rich Seeds Flaxseed Flaxseed comes from plants native to Eurasia, species of Linum and especially L usitatissimum, which have been used for more than 7,000 years as a food and to make linen fiber The small, tough, reddish-brown seed is about 35% oil and 30% protein, and has a ... Missouri Another American species, the butternut (J cinerea), is even less known, but remarkable for its high protein content — near 30% — and esteemed by enthusiasts as among the tastiest nuts The Japanese have an... ailantifolia, one of whose varieties is the distinctively heartshaped heartnut Characteristics of Other Oil-Rich Seeds Flaxseed Flaxseed comes from plants native to Eurasia, species of Linum and especially L...commonly used to make breads, confections, and ice creams, but it’s difficult to extract from the shell in large pieces and has been largely ignored Most still