Phyllocladus, the celery pines, is a small genus of conifers, now usually placed in the family Podocarpaceae. Species occur mainly in New Zealand, Tasmania, and Malesia in the Southern Hemisphere, though P. hypophyllus ranges into the Philippines, a short way north of the equator.
The order Pinales in the division Pinophyta, class Pinopsida, comprises all the extant conifers. The distinguishing characteristic is the reproductive structure known as a cone produced by all Pinales. All of the extant conifers, such as Araucaria, cedar, celery-pine, cypress, fir, juniper, kauri, larch, pine, redwood, spruce, and yew, are included here. Some fossil conifers, however, belong to other distinct orders within the division Pinophyta.
Multiple molecular studies indicate this order being paraphyletic with respect to Gnetales, with studies recovering Gnetales as either a sister group to Pinaceae or being more derived than Pinaceae but sister to the rest of the group.
Phylloclades and cladodes are flattened, photosynthetic shoots, which are usually considered to be modified branches. The two terms are used either differently or interchangeably by different authors. Phyllocladus, a genus of conifer, is named after these structures. Phylloclades/cladodes have been identified in fossils dating from as early as the Permian.
Podocarpaceae is a large family of mainly southern hemisphere conifers, known in English as podocarps, comprising about 156 species of evergreen trees and shrubs. It contains 20 genera if Phyllocladus is included and Manoao and Sundacarpus are accepted. The family achieved its maximum diversity in the Cenozoic, making the Podocarpaceae family one of the most diverse in the southern hemisphere.
The family is a classic member of the Antarctic flora, with its main centres of diversity in Australasia, particularly New Caledonia, Tasmania, and New Zealand, and to a slightly lesser extent Malesia and South America (primarily in the Andes Mountains). Several genera extend north of the equator into Indochina and the Philippines. Podocarpus reaches as far north as southern Japan and southern China in Asia, and Mexico in the Americas, and Nageia into southern China and southern India. Two genera also occur in sub-Saharan Africa, the widespread Podocarpus and the endemic Afrocarpus.