The families of gymnosperms
Podocarps, Yellow-woods, Red Pine, Huon Pine, Celery-top Pine, Prince Alberts Yew.
Vegetative. Evergreen; trees and shrubs. Resinous (with resin canals in the leaves, but only resin-containing parenchyma cells elsewhere). The leafy branchlets flattened in one plane, or not flattened. Phyllocladineous (Phyllocladus), or with normal leaves. Mature leaves relatively broad and flat, or linear, or scale-like; when linear, acicular, or relatively soft; not clustered; alternate (mostly), or opposite and decussate (decussate, in Microcachrys). Longitudinal resin canals present in the leaves, or absent from the leaves; when present, 1 per leaf, this median-abaxial.
Reproductive organization. Monoecious (rarely), or dioecious. The ovules borne in female cones (the cones few-bracted, and each bearing only one seed to maturity), or not in cones (ostensibly, the cone being sometimes reduced to a swollen, fleshy receptacle with a single terminal ovule, so that its morphological homologies are esoteric); ostensibly terminating axes, or borne proximal-adaxially on the seed-cone scales (except in Phyllocladus and Microstrobus, the vestigial ovuliferous scale is usually more or less folded round the ovule, constituting an extra envelope designated the epimatium, which is itels sometimes fused to the integument). The bract-scales more or less free of the seed-cone scales in mature cones. The seed-cone scales assuming they are recognised as such, 1 ovuled. The ovules orthotropus (rarely), or anatropous.
Male cones catkin-like, with numerous sporophylls each bearing two sporangia. Pollen-sacs 2 per microsporophyll. Pollen with air bladders (2 or 3, sometimes well developed, sometimes poorly developed or vestigial), or without air bladders (e.g., Saxegothaea). The pollination mechanisms are diverse, being by liquid drop mechanism only when the grains are equipped with well developed air bladders (cf. Pinaceae).
Seeds and seedlings. Seeds with a fleshy investment; the fleshy investment variously receptacular, or representing a genuine aril, or developed from the cone-scales, or developed from the integument (individually or combinations); wingless. Cotyledons 2.
Wood anatomy. Growth rings indistict, or distinct. Heartwood present and distinctively coloured, or present but not distinctively coloured, or absent. Latewood not conspicuous. Wood without distinct odour; without distinct taste; not greasy; with dimpled grain (Podocarpus spicatus), or without dimpled grain (usually). Tracheids with neither alternate nor opposite bordered pits; without callitroid pit-border thickenings. Margins of the tori not scalloped. Torus extensions conspicuously present (e.g., in Lagarostrobus), or absent. Earlywood tracheids without spiral thickenings. Axial parenchyma present, or absent. Axial parenchyma when present, abundant, or scarce. Axial parenchyma not zonate. Axial parenchyma with nodular thickenings or bead-like on the transverse or end-walls (Saxegothaea), or without nodular thickenings on the transverse or end-walls. Ray tracheids regularly present (usually, in Podocarpus), or absent or very infrequent. Ray tracheids when present, not dentate. Earlywood ray cells with horizontal walls thinner than those of the adjacent vertical tracheids above and below the ray, or with walls similar in thickness to those of adjacent vertical tracheids. Latewood ray cells with unpitted horizontal walls, or with pitted horizontal walls. The pitting wen present, strong, or weak. Ray cells exhibiting indentures at the corners, or without indentures; without nodular thickenings on their end walls. Ray tissue without crystals. Earlywood cross-field pits 1(-3), large and simple (or nearly so), or cupressoid, or 1(-3), large and simple (or nearly so) and taxodioid, or cupressoid and taxodioid, or taxodioid. Normal vertical resin ducts absent.
Geography, cytology. Mostly Southern hemisphere, extending north to Japan, Central America and West Indies.
Basic chomosome number, n = 9–19 (only 14 and 16 unrepresented).
Taxonomy. 173 species; Acmopyle, Afrocarpus, Dacrydium, Dacrycarpus, Falcatifolium, Halocarpus, Lagarostrobus, Lepidothamnus, Manoao, Microcachrys, Microstrobos, Nageia (Decussocarpus), Parasitaxus, Phyllocladus, Podocarpus, Prumnopitys, Saxegothaea, Sundacarpus. Order Coniferales.
Miscellaneous. • Saxegothaea conspicua (Lindley). • Saxegothaea conspicua (Dallimore and Jackson). • Saxegothaea conspicua (Chittenden). • Phyllocladus rhomboidalis (Lindley). • Phyllocladus trichomanoides (Dallimore and Jackson). • Podocarpus salignus (Dallimore and Jackson). • Prumnopitys andina (Dallimore and Jackson). • Podocarpaceae: technical details (Sporne). • Cone morphology: Podocarpus spp. (Florin). • Cone morphology: Microcachrys, Phyllocladus, Saxegothaea (Florin). • Leaf epidermis: Podocarpus ferrugineus and Podacarpus blumei (Florin). • Wood anatomy: Lagarostrobus franklinii.
To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2008 onwards. The families of gymnosperms. Version: 9th April 2015. delta-intkey.com’.