KINGDOM PLANTAE (The Plant Kingdom)
SUB KINGDOM DIVISION
Bryophytes Bryophyta (bryophytes)
Seedless vascular plants Psilophyta (psilopods)
Seed Plants Cycadophyta (cycads)
These are the cycads. Cycads have an appearance like palms, but unlike palms they do not flower. They have sluggish cambial growth, pinnately compound, palmlike or fernlike leaves, and they produce a cone in the centre of their crown (not unlike a conifer cone). Cycads are mainly subtropical southern hemisphere plants, though there are some which come from other areas. There are about 10 genera and about 100 species.
Containing only one species (Gingko biloba), which has considerable cambial growth, fan-shaped leaves, ovules and seeds exposed, with the seed coats fleshy. This species is commonly included loosely as a conifer in many gardening texts.
This is an isolated group of plants of three genera: Gnetum, Ephedra and Welwitschia which contain about 70 species. They are not commonly grown.
These are the conifers. Most are trees, and most are from cooler climates, however there are also some tropical species. They have active cambial growth and simple leaves. There are about 50 genera and 550 species (plus thousands of cultivars).
Conifer Families & Genera
Evergreen trees & shrubs, from Sth Hemisphere, broad or needle-like foliage.
Two genera in this family: Agathis, Araucaria
Evergreen trees or shrubs with narrow, erect, evergreen leaves, similar to Taxus.
One genus in this family: Cephalotaxus
Usually heavily branching plants, trees or shrubs, upright or spreading, leaves in whorls or 3 (occasionally 4). Genera in this family include: Actinostrobus, Callitris, Calocedrus (Incense Cedar), Chamaecyparis, Cupressus, Diselma, Fitzroya, Fokienia, Juniperus, Libocedrus, Microbiota, Neocallitropsis, Papuacedrus, Sabina, Tetraclinis, Thuja, Thujopsis, Widdringtonia
Shrubs, twiggy growth with sparse foliage. One genus in this family: Ephedra
Mainly trees, occasionally shrubs, usually with needle like foliage, from Northern hemisphere. Genera in this family include: Abies, Cathaya, Cedrus, Keteleeria, Larix, Picea, Pinus, Pseudotsuga, Pseudolarix, Tsuga
Evergreen trees & shrubs; flattened, scale or needle-like foliage.
Genera in this family include: Acmopyle, Dacrydium, Microcachrys, Microstrobos, Phyllocladus, Podocarpus
Genera in this family include: Amentotaxus, Austrotaxus, Pseudotaxus, Taxus, Torreya
Tall trees, evergreen or deciduous, foliage usually arranged spirally around stems.
Genera in this family include: Athrotaxis, Cryptomeria, Cunninghamia, Glyptostrobus, Metasequoia, Sciadopitys, Taiwania, Sequoia, Sequoiadendron, Taxodium
Low growing plants with a short woody stem, long leathery strap-like leaves.
One genus in this family: Welwitschia
Many conifer species are very hardy, and can survive climatic conditions. Their softwood that is easily worked, and the fast growth of some species make some conifers very valuable for their timber. While many large conifer plantations exist solely for the production of softwood products, increasingly landowners are applying agroforestry concepts to their farming practices as the benefits of such versatility comes to be better understood.
In addition, there are a huge number of conifer cultivars in an amazing array of colours, sizes, and shapes for use as ornamentals.