Classical Latin name for the pine.
Mostly tall, resinous, evergreen trees. Bark thick, furrowed, sometimes in large, coloured plates or thinly peeling. Winter buds cylindrical to ovoid, scaly and sometimes resinous. Branches in whorls; on some species only 1 but on others 1-4 whorls produced each year. Shoots of two types; long shoots which make up the branch framework, and short shoots arranged spirally on the long shoots. Leaves are of 3 kinds: (1) the main photosynthetic leaves, called needles, are in groups (called fascicles, from the latin word meaning bundle) of 2, 3 or 5 (P. monophylla Torr. ex Frém. has 1, and a few species have variable numbers) - it is the needle leaves that are referred to as leaves in the following text and descriptions. The leaf fascicles are united at the base by a sheath which may be persistent or deciduous; at its centre is a dormant bud that can develop into a long shoot if the main shoot is broken. (2) Less obvious are the single triangular to lanceolate brown scale-leaves on the long shoots; they may have a short shoot in their axils. (3) The juvenile leaves seen on seedlings. Needle leaves usually have 2 or more resin canals, the number and pattern of canal distribution often differing between species. Male and female cones are borne on the same tree in the axils of the scale-leaves. Male cones are usually small, yellowish and catkin-like in clusters at the base of the current season's growth. Pollination is by wind in spring when the male catkins are active. Female cones are solitary or in groups, pendulous, erect or spreading, woody or flexible, ripening in 1.5-3 years, mostly terminal or nearly so on the current season's growth, though they may persist for many years and are shed entire; scales with the tip, known as an umbo, either dorsal (in the centre of the scale), or terminal (at the tip of the scale) often ending in a spur, spine or prickle. Seeds 2 on upper surface of each cone scale, winged, though in many species the wing is reduced to a vestigial rim on the seed.
The time taken by young trees to produce cones varies widely but is generally from 10-20 years. Pinus radiata is the most commonly encountered pine in parklands, large gardens and farms where it is used for shelter and as a windbreak. Pinus canariensis is also quite widely cultivated in public parks and gardens, possibly dating back to the periods 1888-95 and 1927-31 when it was planted experimentally for forestry. P. halepensis is popular in hotter areas such as north-western Victoria and parts of South Australia. A wide range of pine species was grown experimentally in public parks and gardens in the late nineteenth and early twentieth century to assess both their commercial and aesthetic potential. These are now mature specimens but, being no longer regarded as ornamental trees, they have not been replaced, so the diversity of cultivated species is likely to diminish although a few of the highly ornamental warm-climate Mexican species are now being offered in nurseries. Several species from mild climates that will not grow well in cool temperate climates such as that of the United Kingdom, thrive in south-eastern Australia: these include P. canariensis, P. elliottii, P. halepensis, P. palustris , P. patula and P. torreyana.
The pines comprise the largest conifer genus with over 110 species. They are the dominant conifers of the Northern Hemisphere (in contrast to the podocarps of the Southern Hemisphere) and are the most important economically. They are mostly temperate but range from 70° N in the Arctic to the tropics, being widely distributed from the cool areas of Europe, Asia and North America to the sub-tropical regions of N Africa, Canaries, C America and the Philippines. In the Americas they extend south to 12° S with 45–50 species in C America and Mexico (where 9 species are rare or threatened by logging and clearance). In tropical areas, such as Sumatra & C America, they are mainly found at high altitude, although 3 occur in lowland areas of SE Asia and the Caribbean; one of these just crosses the equator in Sumatra.
A major source of timber, turpentine, pitch and rosin and the cones for ornament. The bark is used as a garden mulch. Some species have edible seeds, notably the Stone Pine, P. pinea. A few species are used for agroforestry.
Plantation Pines: In Australia Pinus radiata, Radiata Pine (as the timber is known), is the major commercial plantation pine in most states. It is easily cultivated with a rapid growth rate and produces good timber (P. canariensis and P. palustris produce a better quality timber but their growth rate makes them uneconomical). Selected clones are now proficiently propagated by tissue culture. In Western Australia P. pinaster is also widely planted. In New South Wales Pinus radiata is planted in the south of the State, but north of Sydney with higher temperatures and summer humidity P. elliottii , Slash Pine, from SE USA (needles 20-30cm long, slender, in 2's &3's) takes over from P. radiata and has become naturalised around plantations. Good specimens can be seen in New South Wales at Kippenduff (at Casino in 1975 there was a 36 m tall specimen planted in 1928) also at Barcoongerie State Forest. New South Wales also has some plantations of P. taeda, Loblolly Pine. The warm-climate P. elliottii and P. taeda from the southern United States are sometimes referred to as "Southern" pines. In SE Queensland Slash Pine is widely grown on the Darling Downs for its timber, also in the Beerburrum and Maryborough areas on sandy, nutrient-poor soils. Pinus caribaea Morelet. (leaves in 3's & 4's) of C America, Caribbean Pine, is used extensively in coastal Queensland plantations and the tropics; it hybridises with P. elliottii and is recommended for agroforestry on the Atherton Tableland. Old plantings remain of P. patula (SE Qld) and P. taeda (Beerburrum, Gympie). In the ACT there are many pine plantations, mostly of P. radiata, but for the conifer enthusiast prepared to search there are many experimental conifer forestry collections (pineta) in different soils and at different altitudes containing a wide range of species. All the major plantation pines have shown a tendency to naturalise and in South Australia P. halepensis although little used as a plantation species, has naturalised from other sources. In the early 1850s in Victoria there was large-scale and destructive cutting of native forest in gold-mining districts. This, together with the lack of softwood, prompted the establishment of a nursery at Mt Macedon in 1872 to provide stock for plantations. Often early plantings served the purpose of land reclamation and soil stabilization as much as timber production. The demand was so great that 4 more nurseries were established during 1888-90 at Creswick, Havelock (near Maryborough), Gunbower Is. (Murray River) and the You Yangs. The earliest pine plantations in Victoria, well over 100 years ago, were of P. muricata and P. nigra var. corsicana, the latter being a major timber pine of the Northern Hemisphere. It was only in the 1880s that P. radiata became the major plantation pine (although it had been recommended by Mueller as early as 1859) and it is now virtually the only pine grown commercially, although P. pinaster was once used quite extensively in nutrient poor coastal sands (some stands remaining, for instance, at Frankston) and P. ponderosa was trialled quite extensively. Pinus nigra var. corsicana persists in older plantations. Histories of forestry have recently been written for New South Wales (Grant, 1989) and Victoria (Moulds, 1991).
VIC: A wide selection of species may be seen in the Creswick Forestry School (in spite of huge losses after the Ash Wednesday fires of 1983); a commercial softwood demonstration area displays many species in labelled rows. Other areas of interest include the Mt Dandenong Arboretum, Eastern Park Geelong, Victoria Park Beechworth and Kings Domain Melbourne and at the Merreweather Arboretum, Dunkeld, property of Mr Bill Funk. Eighty species, still very young, were recorded for the Otway Ridge Arboretum in 1991. SA: At the Waite Arboretum, Adelaide there are 23 species (1989) with an emphasis on SW North American species and at least 8 species with edible seeds. Probably South Australia's most extensive collection is at the Mt Lofty Botanic Garden, Adelaide which has about 50 species (1991) and many cultivars, although these are still very young. ACT: Westbourne Woods (Royal Canberra Golf Club) 30 species were recorded in 1983. In New Zealand there is an exceptional collection at the Rangiwahia Pinetum near Taihape on the North Island which recorded 92 taxa of pines in 1990.
Diseases: These include Pine Needle Blight caused by the fungus Dothiostroma septospora which causes needle drop in young trees in P. radiata plantations. In 1989 this was a problem in Victoria, especially in the north east, where 10% of the plantations were affected. Sirex wasp, Sirex noctilio, spreads a fungal disease that causes wilting of the leaves which change to yellow then brown. Browning of the tree top and holes 3-7mm wide in trunks indicate the presence of the Sirex Wasp and its larvae. After weakening by adverse weather conditions, especially hail, trees such as P. radiata may suffer from browning of leaves and death after succumbing to fungal Shoot Blight, Sphaeropsis sapinea.
Pines can be easily divided into artificial groups according to the number of needles per bundle, but it is sometimes difficult to separate the species within a group. With a little experience many pines may be recognised by their habit and the pattern and colour of the bark; see if the bark is smooth, scaly or deeply fissured, and what colour it is on the trunk and in the upper crown. Note whether the branches are horizontal, ascending or curving upwards like a candelabra. Other useful characters include the shape and size of the new growth buds, whether they have any encrusting resin, and the kind of bud scales, whether fringed, closely pressed down or curled back. The stems of 1-year-old shoots, green at first, soon take up a coloration or waxy bloom that is characteristic of the species. Needle length, thickness and colour can be good guides (only typical mature leaves should be used), and sometimes the enclosing sheath at the base of the needle cluster gives identification clues, although older leaves do not retain typical sheath characteristics and may be misleading. It is the structure of the unweathered cones that is most useful for identification; observe whether they are soft or hard, single or in clusters, the shape of the tips of the scales (umbos) which may have spines, prickles or spurs, and whether they have a sealing band; also the presence and length of any stalk, the cone's persistence on the tree and if so whether they remain unopened for several years or not. With a microscope it is possible to distinguish most species by the anatomy of the leaves using the position of resin canals and conducting tissues.
The subgeneric classification of the pines varies between botanical authorities. However, the genus is generally now divided into 3 distinct subgenera (based largely on cone structure and internal needle anatomy) and these subgenera may be given generic status in future: Strobus - the White or Soft Pines; 23 species, from cool, or warm moist areas. Cone cylindrical or rarely ovoid; scales with a terminal protuberance (umbo) and no sealing band where they meet on the closed cone. Seeds with a strongly joined wing. Needles with a single vascular bundle in section, 5 per fascicle, sheath deciduous e.g. P. strobus, P. wallichiana. Ducampopinus - Lacebark, Pinyon or Foxtail Pines; 22 species, mostly from dry areas. Cone globose to ovoid or cylindrical; scales with a dorsal umbo and no sealing band. Seeds with an easily separable wing. Needles with a single vascular bundle; 1-5 per fascicle, with a partly to fully deciduous sheath e.g. P. cembroides. Pinus - Hard Pines; about 67 species widely distributed. Cones ovoid to conic; scales with a dorsal umbo and and no sealing band. Seeds mostly with a separable wing. Needles with 2 vascular bundles, 2-5 per fascicle; sheath mostly persistent e.g. P. radiata, P. halepensis. In general the 5-needle pines are from subgenera Strobus and Ducampopinus and the remainder from subgenus Pinus.
Needle leaves in fascicles of mostly 2, 3 or 5, held together at the base by a membranous sheath.
Lanyon (1966), Mirov (1967), Little & Crichfield (1969), Horsman (1981), Farjon (1984), Hawker (1987, 1991), Crichfield (1986), Klaus (1989), Rushforth (1987), Frankis (1989a), Perry (1991), Muir (1992).
The key to Pinus - This key is based on established mature trees but can be used for any tree more than about 5 years old. It covers all the species common in gardens and forestry and a few rarer species. For a selection of rarer ornamental species suitable for Australian conditions see Frankis (1989, 1990a). The range of species available in the nursery trade is variable and may include a few rare species not included here.
Source: (1995). Pinaceae. In: . Horticultural Flora of South-eastern Australia. Volume 1, Ferns, conifers & their allies. The identification of garden and cultivated plants. University of New South Wales Press.