Pilgerodendron is a genus of conifer belonging to the cypress family Cupressaceae. It has only one species, Pilgerodendron uviferum, which is endemic to the Valdivian temperate rain forests and Magellanic subpolar forests of southern Chile and southwestern Argentina. It grows from 40 to 54°20' S in Tierra del Fuego, where it is the southernmost conifer in the world. It is a member of subfamily Callitroideae, a group of distinct Southern Hemisphere genera associated with the Antarctic flora. Pilgerodendron is very closely related to the New Zealand and New Caledonian genus Libocedrus, and many botanists treat P. uviferum within this genus, as Libocedrus uvifera (D.Don) Pilg. It is also a taxonomical synonym for Libocedrus tetragona (Hooker). The species is known locally as ciprés de las Guaitecas (after the Guaitecas Archipelago), and elsewhere by its scientific name, as pilgerodendron. The genus is named after Robert Knud Friedrich Pilger. P. uviferum is a dioecious, slow-growing, narrowly conical evergreen tree that grows from 2–20 m in height, with a trunk up to 1.5 m in diameter. Taller specimens and wider trunks (reportedly up to 3 m in diameter) are known to have existed before it was overexploited. The leaves are scale-like and arranged in decussate pairs, with each leaf equal in size, giving the shoots a square cross-section (unlike the Libocedrus species, where pairs of larger leaves alternate with pairs of smaller leaves, giving a somewhat flattened shoot). The seed cones are 5–12 mm long and 4–6 mm broad, with four scales, two sterile basal scales and two fertile scales; each scale has a slender spine-like bract, and each fertile scale has two winged seeds 3–4 mm long. The pollen cones are 5–10 mm long and 2 mm broad, with 12–20 scales. It is found in the evergreen coastal lowland forests along the Pacific coast of southern Patagonia, in association with the broadleaf evergreens Nothofagus betuloides and Drimys winteri. It is also found in open stands in sheltered bogs farther inland, where it is often locally dominant, and ranges as far as the eastern slopes of the Andes in southwestern Argentina. At the northern end of its range it is found in association with Fitzroya cupressoides. The northernmost natural stands are found in 39°50' in the vicinity of the city of Valdivia. The conservation status of P. uviferu, in the far north of its natural distribution is poor, being fragmented by exotic plantations, threatened