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A genus of a single species in Japan, distinct from all other living conifers in its foliage. The leaves are of two kinds: those on the long shoots are small and scale-like, the upper ones crowded; the foliage leaves are flattened and ‘double’, each being apparently composed of two completely connate needles borne on an undeveloped spur springing from the axil of a scale-leaf. Owing to the crowding of the subtending scale-leaves, the foliage leaves form whorls at the ends of the shoots, like the ribs of an umbrella. The nature of the foliage leaves is a matter of controversy; according to some botanists they are what they appear to be, i.e., the result of the fusion of two distinct needles, while others consider them to be modified shoots (cladodes) and the occasional occurrence of branched needles is adduced to support this theory (Rev. Hort., 1884, p. 16). Double needles have been found in Cretaceous deposits, so this form of photo-synthetic organ is very ancient. Male and female flowers are borne on the same tree. The female cones are solitary at the ends of the branches; fertile scales in the flowering stage small, subtended by conspicuous bracts, but becoming much larger as the cone develops (it needs two years to ripen). Mature cones have numerous spirally arranged woody scales, each fertile one bearing five to nine narrowly winged seeds.