Athrotaxis laxifolia / Summit athrotaxis

Athrotaxis laxifolia, first described in 1843 by Sir William Jackson Hooker (1785 – 1865), is commonly known as Summit or Yellow-twig athrotaxis. According to the book, Australian Conifers, published by Australian National Botanic Gardens (ANBG), the species name laxifolia refers to the wider spacing of the leaves as compared to the spacing of leaves of other species belonging to the same genus. These trees are thought by some to be a hybrid of A. cupressoides and A. selaginoides because individual trees are only found in areas where both of the other species occur. The foliage is also intermediate in appearance between the other two species.

Description. Summit athrotaxis is a monoecious evergreen coniferous species of tree which will grow to a mature height of 40 to 65 feet (12 - 21 m) tall with a conical, sparsely branched crown. Its bark is dark orange-brown, deeply fissured, flaky and exfoliating. Seasonal branchlets are pale to bright yellow. Leaves are ovate-lanceolate, slightly spreading, acute, 024 inch (6 mm) long, with 2 white bands of stomata below, complete, translucent margins with an incurved apex. Male cones occur with 2 pollen sacs. The ovoid female cones are produced in pairs, densely clustered at the ends of short shoots, pale to bright yellow in color, 0.6 to 1.2 inches (1.5 - 3 cm) wide, on a peduncle, ca. 0.1 inch (2 - 3 mm) long. Seeds have 2 narrow wings which aid in wind dispersal.

Distribution. This species is native to Australia — the island of Tasmania, growing in mountain rain forests at elevations of 2,900 to 3,850 feet (900 to 1,200 m) above sea level.

Attribution from: Silba, J. ©1986. An international census of the Coniferae. Phytologia memoir no. 8. Corvallis, OR: H.N. Moldenke and A.L. Moldenke.