Phyllocladus

Phyllocladus
Scientific classification
Kingdom: Plantae Division: Pinophyta Class: Pinopsida Order: Pinales Family: Phyllocladaceae Genus: Phyllocladus
Species
Five; see text

Phyllocladus is a small genus of conifers, now treated in the Family Podocarpaceae. They are morphologically very distinct from the other genera in that family, and some botanists treat them in a family of their own, the Phyllocladaceae. However, genetic analysis shows that they fall within the Podocarpaceae; their removal from this family leaves the remainder of Podocarpaceae as a paraphyletic taxon. As modern scientific classification requires taxa to be monophyletic, Phyllocladus is best treated within the Podocarpaceae.

This genus is mainly a southern hemisphere genus, occurring in New Zealand, Tasmania and Malesia, where one species crosses a short way north of the equator in the Philippines.

They are small to medium-size trees, reaching 10-30 m tall. The main structural shoots are green for 2-3 years, then turn brown as the bark thickens. The leaves are sparse, tiny, scale-like, 2-3 mm long, and only green (photosynthetic) for a short time, soon turning brown. Most photosynthesis is performed by highly modified, leaf-like short shoots called phylloclades; these develop in the axils of the scale leaves, and are simple or compound (depending on species). Simple phylloclades are rhombic, 2-5 cm long, and compound phylloclades are up to 20 cm long and subdivided into 5-15 'leaflet'-like phylloclades 1-3 cm long. The seed cones are berry-like, similar to those of several other Podocarpaceae genera, notably Halocarpus and Prumnopitys, with a fleshy white aril; the seeds are dispersed by birds, which digest the soft fleshy aril as they pass the hard seeds in their droppings.

• Species
  • Phyllocladus alpinus (P. trichomanoides var. alpinus) - Mountain Toatoa (New Zealand)
  • Phyllocladus aspleniifolius - Celery-top-pine (Tasmania)
  • Phyllocladus hypophyllus - Malesian Celery-pine (New Guinea to Borneo & Philippines)
  • Phyllocladus toatoa - Toatoa (New Zealand)
  • Phyllocladus trichomanoides - Tanekaha (New Zealand)

References

• Quinn, C. J. & Price, R. A. 2003. Phylogeny of the Southern Hemisphere Conifers. Proc. Fourth International Conifer Conference: 129-136.

External links

• Gymnosperm Database - Phyllocladus