The megasporangiate strobili, 3 to 5 cm in length, are formed as reddish conelets in upper portions of the crown. The cones have two types of bracts, a seed-bearing scale and auxiliary bracts, 3 to 4 mm in length, that are formed at the base of the scales and not visible in the closed cone. Each fertile cone scale bears two embryos, developing into two winged seeds, 4-5 mm long, triangular in shape, and brown to back in color. In mature cones, the scales become ligni-fied and woody. The shape of the cone scales is highly variable among provenances, ranging from a more rounded shape in eastern provenances, resembling the subspecies obovata, to an elongated form similar to 'acuminata' in the western portions of the species range. A number of studies have analyzed cone trait variation in relationship to the geographic distribution of the species (see also Chapter 5). Seed mass varies between 2.68 and 10.0 g per 1000 (ANDERSSON 1965). Seeds of southern provenances tend to have a slightly higher mass than northern and eastern sources (TYSZKIEWICZ 1934b, DUTKIEWICZ 1968).
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