A revision of the Malesian and Pacific rainforest conifers, I. Podocarpaceae, in part

Abstract

ARNOLD ARBORETUM [vo.50 the leaves are distinctly bilaterally flattened, often spread out distichously, yet this character is usually lost in the mature form.Elsewhere among the conifers only in Falcatifolium and Acmopyle are bilaterally flattened leaves found but without change in the adult form.Where the foliage leaves are bilaterally flattened or acicular, sterile specimens of Dacrycarpus can be identified by the sharply dimorphic leaves because the penultimate branches always have bifacially flattened leaves or scales.Dacrycarpus is composed of nine species ranging from Burma to New Zealand.Some of the species are geographically isolated and the one species in New Zealand (D. dacrydioides) is not tropical in habitat.The various species are distinguished primarily by the shape of the involucral leaves subtending the receptacle and the shape of the foliage leaves.Most discussion of specific differences in the morphology of the seed-complex simply involves degrees of maturity.Among the various species there are several wide ranging groups.A more or less scale-leaved type involves D. dacrydioides and D. imbricatus and is the most important for lumber and afforestation.Longer acicular leaves and a relation to moist habitats characterize D. steupit and D. vieillardiu.Long involucral leaves and a mid-mountain distribution are characteristic of D. cumingi and D. cinctus.The remainder of the species are mostly localized and are found at high elevations.KEY TO THE SPECIES OF DACRYCARPUS 1. Involucral leaves spreading and not enclosing the seed and receptacle at all; mature leaves not distinctly flattened.2. Leaves short to scale-like (less than 2 mm.). 3. Pollen cones terminal, linear; involucral leaves very short, not longer than the foliage leaves...... :....a5enee (D. dacrydioides).3. Pollen cones lateral, ovoid; involucral leaves about as long as the re-'ceptacle and longer than the foliage leaves.4. Leaves slender (0.4-0.6 mm.wide). 5. Leaves imbricate......... 21a.D. imbricatus var.imbricatus. 5. .Leaves*spreading.. ... 40 unten 21b.D. imbricatus var.patulus.4. Leaves robust (0.6-1.0 mm.wide).6. eaves spreading.=< 750s ee 21c.D. imbricatus var.robustus.6. (Leaves Imbricate-.). 4 Gee 21d.D. imbricatus var.curvulus.2. Leaves elongate (at least 2 mm.).7. Involucral leaves less than 2 mm.(shorter than the foliage leaves); foliage leaves strongly variable and more or less imbricate......... ake bcuelet Shem PRR.olden Ie sr 22. D. vieillardi.7. Involucral leaves more than 3 mm.(longer than the foliage leaves); foliage leaves more constant and strongly spreading...........