- Norfolk Island Pine
- Planting and Care
- Caring for a Norfolk Pine
- Secrets to Success
- Signs of Trouble
- Decorating Norfolk Pines for the Holidays
- Question: Saving a Cold Damaged Norfolk Pine
- Question: Identifying Cold Damage to Norfolk Pine
- Question: Growing a Norfolk Pine Indoors
- Question: Cleaning Dust on Norfolk Pine
- Question: Branches Curling on Norfolk Pine
- Question: Separating Two Norfolk Pine Trees Growing in One Pot
- Question: Caring for a Norfolk Pine
- Question: Fertilizer for Outdoor Norfolk Pine Trees
- Question: Pruning a Norfolk Pine
- Archive: Caring for a Norfolk Pine
Norfolk Island Pine
Norfolk Island pine (Araucaria heterophylla) is a popular houseplant gift during the holidays. Often given to be used as a small Christmas tree, these wonderful little trees can brighten your home long after the holidays end.
While this tree can grow quite large in its natural habitat, Norfolk Island pine is slow growing. After about a decade, it may eventually reach 5 to 8 feet tall as a houseplant, but this potted tree will not surprise you with explosive growth.
As with so many holiday gift plants, some Florida gardeners may be able to plant their Norfolk Island pine in their landscape after they are done enjoying its beauty indoors. It should be noted though, that this naturally coastal tree does not hold up well during hurricanes.
Norfolk Island pines are not true pines; they are members of a pre-historic family of conifers Araucariaceae, an incredibly diverse and widespread plant family during the Jurassic and Cretaceous time periods. The end of the Cretaceous period saw not only the extinction of the dinosaurs, but the extinction of members of the Araucariaceae family in the northern hemisphere. However, in the southern hemisphere, members of the Araucariaceae family continued to thrive. Today there are three genera—Agathis, Arucaria, and Wollemia—with a combined total of 41 species.
Norfolk Island, where this tree hails from, is located in the South Pacific between Australia, New Zealand, and New Caledonia. The flag of this Australian territory actually features the Norfolk Island pine. While sold here in the states as tabletop Christmas trees, in their native habitat these plants can incredibly reach 200 feet tall and have trunks that swell to 10 feet in diameter! In Florida these trees typically grow to only 60 to 80 feet.
This mature Norfolk Island pine in a New Zealand park is so tall, the people standing next to tree look like ants.
While not true pines, their tiered branches, slender pyramidal or columnar shape, and narrow evergreen leaves appear pine-like. Norfolk Island pines have a single upright trunk and occasionally develop a graceful lean. These trees are tropical plants that thrive on humidity and can’t tolerate temperatures below 35°, so Orlando is the approximate northern range of this plant. Naturally found in coastal areas, it is no surprise that these plants have a high salt tolerance.
Planting and Care
Indoors, these plants need quite bright light and humidity. If your find that your plant is not thriving, in all likelihood it is likely not receiving sufficient light or humidity.
In Florida we know all about humidity, but we strive to keep it out of our homes, so how do you make it humid for your houseplants? Overwatering is not the answer; Norfolk Island pines don’t appreciate being too wet. Instead, fill a saucer with water and rocks or gravel, then place the potted plant on top making sure the pot is not sitting directly in water. There you have it—you’ve created your own little high-humidity microclimate. When you find the spot in your house with the right light for your plant, don’t forget to turn the plant every week or so to keep it growing straight and upright.
If you are planning to give your Norfolk Island pine a spot in your landscape, remember that these trees get quite large. Be sure you have the room for a 60 to 80 foot mature tree. If not, consider simply enjoying this lovely little tropical tree in your home.
Also on Gardening Solutions
- Holiday Gift Plants
- Living Christmas Trees
- Araucaria heterophylla: Norfolk Island Pine
- Norfolk Island Pine Recovery from Hurricane Charley (PDF)
Caring for a Norfolk Pine
Article: The Norfolk Pine – A Perfect Living Tree for the Holidays
December 6, 2007
If you’re looking for the perfect potted Christmas tree, consider the Norfolk Pine. They have soft, compact needles, a naturally symmetrical shape and they come in a variety of sizes-small enough for a table-top display in the kitchen or hall, or large enough to be the focal point of a large room. Best of all, they are easy to grow, and make a beautiful indoor tree all year long.
Secrets to Success
Growing any plant successfully requires meeting its needs. Generally speaking, Norfolk Pines are easy to grow and are known to be fairly forgiving of less than ideal growing conditions.
Temperature: They will not survive a harsh winter outdoors, but despite the fact that the Norfolk Pine hails from the South Pacific, it isn’t terribly picky about temperature. Temperatures on their native Norfolk Island are in the temperate 65-75ºF range (summer) and 43-50ºF (winter), but these pines grow best on the cooler side of the range. Optimum daytime temperatures from spring to early autumn are in the 60-65ºF range, with somewhat cooler temperatures (not below 50ºF) at night. In the winter, they prefer temperatures around 50ºF (never below 40ºF).
Light: These pines are known to be tolerant of low light conditions, but prefer the bright, indirect or filtered light of a southern exposure. They will survive, but not thrive for a few years in low artificial light conditions (incandescent or fluorescent lighting in a home or office setting) provided they receive at least 16 hours of light per day. Because this plant has the tendency to bend toward the light, turn it often to maintain symmetrical growth.
Water: During the active growing period (spring to autumn) pines should be watered regularly to keep soil thoroughly moist but not saturated. In the summer, soil should not be allowed to dry out. In the winter, water sparingly after soil has been allowed to dry out. Many experts recommend using rain water that has been allowed to sit (outgas) for 24 hours when misting or watering Norfolk Pines. This is good advice if you have hard water, as lime will mark the tender needles.
Feeding: These are slow growing evergreens so don’t expect to see big growth spurts from your Norfolk Pine. In the wild, they grow up to 200 ft. tall, but when kept as a houseplant, they will reach a maximum height somewhere around 5 ft. Feed them every two to three weeks during the active season with a soluble house plant food, and back off the fertilizer in the winter until new growth appears again in spring.
Humidity: Keeping the humidity levels at optimal levels is probably the most challenging aspect of caring for Norfolk Pines. They are one of the few types of houseplants that actually prefer to be misted with cool water. This becomes especially important in cold climates, where indoor air becomes dry during winter heating. Lack of sufficient humidity will cause the tips of their branches to turn brown and needles to drop off. This is important because once the tips of the branches turn brown, growth will stop from that point. Once the needles fall off, they don’t grow back. Mist them regularly with cool water (especially in winter). If the air in your home is dry, try increasing the humidity around your Norfolk Pine by setting the pot in a shallow tray filled with water and pebbles. You can also use an air humidifier or if you keep fish, place it in the room near your aquarium.
Pruning: Any time you prune a Norfolk Pine, keep in mind that you will stop growth at the point of pruning. For this reason, only prune when you need to remove dead branches or brown tips. When left to grow in their natural state, Norfolk Pines will naturally shed some of their lower branches as they grow. Increasing the humidity will slow this process, but expect to see your pine shed a few branches over time.
Repotting: Keeping your pine root bound will restrict its growth and keep it to a manageable size. Still, Norfolk Pines should be repotted every 3-4 years in the spring. Use a loam-based commercial potting soil, or a home-made mix with plenty of drainage.
Propagation: Seeds can be sown in the spring, but Norfolk Pines are difficult to propagate and take a long time to reach a transplantable size. It is best to buy young plants.
Signs of Trouble
Brown tips on the ends of branches and excessive needle loss are probably signaling a lack of moisture. Make sure soil is kept moist, but not saturated and increase humidity around the plant with frequent mists of cool water. Plants that have too much water will exhibit yellow or brown clumps of needles that fall off with the slightest amount of movement. Back off on watering and check to see that the pot has enough drainage.
Norfolk Pine pests include mealy bugs and scale. Symptoms of mealy bugs include small, cotton-like patches or sooty mold. The best way to get rid of a mealy bug infestation is disrupt the bug’s reproductive cycle. This can be done by spraying plants with an all natural insecticide over a period of weeks. These are readily available at most garden centers and nurseries.
Scale infestations appear either as red or brown bumps, or cotton-like patches along the stems at leaf and branch nodes. They can be controlled by drying them out with an application of rubbing alcohol or applying a horticultural oil directly onto the insects to suffocate them.
Decorating Norfolk Pines for the Holidays
Keep the decorations small and lightweight. To avoid stressing the plant, keep an eye on soil moisture and make sure to remove any ornaments quickly after the holidays. If your decorating your pine with lights, make sure to use bulbs that are cool. Lights that run hot may dry out and permanently damage tender needles, causing them to turn brown or fall off. Consider lightweight paper ornaments or garlands made from popcorn and dried fruit for a more natural look. When the holidays pass, return to a winter care regime until new growth appears in the spring.
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Ask a QuestionHere are the questions asked by community members. Read on to see the answers provided by the ThriftyFun community or ask a new question.
Question: Saving a Cold Damaged Norfolk Pine
November 16, 2019
My Norfolk pine froze! Can I “bring it back” or is it done for? I’m moving to Colorado next week and want to take it, but not if there’s no hope for it. I know the dry climate there will be a challenge. Please help!
November 17, 20190 found this helpful Best Answer
Your tree is already in shock and it is in a very fragile state right now. If you try to dig up this tree and move it anywhere it will die for sure. Plus moving this tree to a cold-weather state is not recommended because this tree needs a warmer climate to survive.
Reply Was this helpful? November 25, 20190 found this helpful Best Answer
Number one question;
You do not say if your Norfolk Pine is planted in a pot or if it is planted outside so many suggestions will not relate to your problem.
A Norfolk Pine will not live outside in Colorado so I’m assuming yours in a potted plant.
You also do not say how old or how big your plant is and those details could make a difference.
I believe you should contact your county extension office and ask them about your Norfolk Pine as carrying a dying plant would be a lot of trouble and might just finish dying on the way. They should be able to help you decide if it can be saved.
I believe that once the limbs turn brown they are usually dying and these do not grow back – only new limbs grow from the top. I have never had needles grow back once they start turning brown although the tree may get new limbs at the top but may loose its nice shape. (I live in Florida – Zone 9.)
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Question: Identifying Cold Damage to Norfolk Pine
December 19, 2017
I purchased a beautiful Norfolk pine that is about 3 ft. tall and it was very soft, as they usually are. I left the tree in the car overnight where temperatures outside can get to 30 degree’s Fahrenheit. When I removed the tree early this morning it was cold and stiff. It is not showing any frost on it nor showing any frostbite damage at this time. What kind of damage will happen and what can I do?
Norfolk Pine cannot be outside in cold weather. They are a house plant no matter the name. My motger had one do the same and the garden center told her to keep it inside. It doesnt take heat well either and will go yellow in the sun.
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Question: Growing a Norfolk Pine Indoors
March 26, 2012
My Norfolk pine is getting too tall for the house. Can I pinch it back?
It is an indoor plant that I put out on the deck in the summer.
By Adrien M
April 3, 20120 found this helpful
Have a look at this for more info on caring for a Norfolk pine:
Reply Was this helpful? January 1, 20132 found this helpful
As far as ensuring proper soil, my indoor Norfolk pine went crazy when watered with leftover diluted coffee straight from the pot. I casually read somewhere that pines like acidity, and coffee is a good source. I thought I would give this tip a try and hope I wouldn’t kill it. OMG! My Norfolk took off like it never drank coffee before :-). I diluted one cup of coffee with two cups of water. Since it is winter now, I have only given her this special drink twice.
I have yet to feed it commercial fertilizer , since I got the plant in early autumm, and not sure about fertilizing in the off months. She is doing great, as is, so I am going to wait till Spring to give the first dose.
My pine’s home is in the living room window, shielded from direct sunlight by lace curtains. I keep the humidity high by sitting the tree on a dry mound of pebbles surrounded by water. I cool mist every other day. My Norfolk is green and healthy, and one of my favorite houseplants! I urge everyone to give a try at growing a Norfolk pine – it is a very rewarding houseplant!
Reply Was this helpful? 2 Anonymous July 2, 20180 found this helpful
Will try the diluted coffee! Nice ! My poor girl is suffering tho. Is 6 ft tall but got too dry by me thenoverwatered by rain
Dropped a quarter of branches and needles. Poor thing needs s boost from coffe or fertilizer or my love. Any ideas how get empty spots to regrow? Help susan
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Question: Cleaning Dust on Norfolk Pine
April 5, 2013
I have forced air heat. My pine has a lot of dust on the needles. What is the best way to clean the plant?
By Peg J
April 8, 20130 found this helpful
If it is inside, it must be in a pot. Take it outside or put it in your bathtub and spray liberally with water. That’s how Mother Nature cleans plants.
Reply Was this helpful? Anonymous April 10, 20170 found this helpful
Shower it in bathroom or outside.
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Question: Branches Curling on Norfolk Pine
September 20, 2015
I have a Norfolk Pine that we bought in spring. It sits in a south window on a table. The pot has drainage. We keep it moist, but not saturated. Lately the branches are starting to curl up and it looks like it has stopped drinking water and does not look heathy. We planted it in a light peat soil. Can this be why? How do I bring it back to being healthy?
November 4, 20170 found this helpful
- This seems to be a problem with the size of your pot.
- You’ll need to re-pot the plant in a larger diameter pot and use new soil.
- Your nutrient levels are off in the soil.
- This could be caused by salt being too high because of fertilizer residual or evaporation.
- Your soil could be in desperate need of nutrients because of constant water leaching.
- Repot the plant in a larger pot, buy the right fertilizer for this type of plant, and use new soil.
- This should help bring your pine back to life.
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Question: Separating Two Norfolk Pine Trees Growing in One Pot
May 17, 2013
I have a Norfolk pine that has two trees in one pot. Can these be split when repotting?
November 11, 20180 found this helpful
My Norfolk pine put out three small extra stems that were growing up into the main plant. I separated them from the main plant and repotted them together as they appeared to be attached to each other. One of the three died back but the other two survived. The main plant grew vigorously and now is over three feet tall above the pot. The smaller plant was kept outside on my deck in the shade from July to September here in Michigan and now has doubled in size over the last 5 months since I’ve separated the plants. Both plants are doing well.
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Question: Caring for a Norfolk Pine
November 28, 2010
I have a Norfolk pine that is now 10 years old and about 10 feet tall. It is a beautiful tree and one that I would hate to lose. It is dropping the needles that appear to be healthy, green, and lush, mainly on the lower limbs. It is putting out a new shoot at the top. It is in a well-lighted area and is watered about once a week soaking it to the bottom. I fertilize it about 4 times a year. Please help me save this tree. Thanks!
Hardiness Zone: 7a
By Kaye Stirsman from Louisville, KY
December 3, 20100 found this helpful
You most likely need to cut back on the watering. either less water the once a week or give it a little longer between watering and never let any water sit in the tray or saucer that is under it. Good luck.
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Question: Fertilizer for Outdoor Norfolk Pine Trees
December 14, 2013
What type of fertilizer is recommended for an outdoor Norfolk pine tree and how often should it be applied? The tree is located in Palm
Beach Florida and is about 5 feet now.
By Margot O.
Question: Pruning a Norfolk Pine
December 8, 2013
My Norfolk pine is very healthy, getting wide, and has long branches. Is it wise to cut back or prune healthy branches?
ThriftyFun is one of the longest running frugal living communities on the Internet. These are archives of older discussions.
Archive: Caring for a Norfolk Pine
November 28, 2010
I bought a Norfolk pine tree back at Christmas time and when I bought it it was below zero and windy. The only time I had it remotely outside in that kind of weather was when I was taking it out of the store and into my house.
Almost immediately the needles started to brown and look like it’s all dried up. Some of the branches are still green, but they snap right off once they get bent with any amount of pressure. I really want to keep this tree alive for this Christmas, but I’m starting to think that it’s not going to make it. Is there any way that I can keep this tree alive? Please help.
Hardiness Zone: 4a
By melvina from Callaway, MN
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ARAUCARIA (Norfolk Island Pine, Money Puzzle, Star Pine) Araucariaceae A. heterophylla A. excelsa & species
HABITAT: South Pacific, South America, Australia, New Guinea, New Caledonia.
USES: House plants, tubs, Christmas tree, patio specimen.
HABIT: Generally fast growing evergreen trees with branches covered 1/2″ needles dependent upon species. Branches are (A. heterophylla) born outward in tiers along the stems. Height and habit dependent upon species. Most are easily controlled in pots and other containers for the home or greenhouse.
SEED GERMINATION AND CULTURE: For best results, sow indoors in spring in sandy soil mix. Barely cover the seed and germinate at a soil temperature of 50-55 degrees, covering seed flat with a sheet of glass to hold in humidity. Keep seed moist during the germination period; remove glass when seed germinates, then transplant when large enough to handle to peat pots or pellets; shifting to larger pots when roots emerge from the pot walls.
Pot up in a commercially prepared soil mix or equal parts of peat moss, leaf mold, and perlite/vermiculite. To each gallon of homemade mix, add 1 1/2 teaspoons of 20% super-phosphate, 1 tablespoon ground limestone, and 2 teaspoons of 5-10-5 fertilizer. Keep the soil barely moist and feed established plants every 3-4 months with a house plant fertilizer. Do not feed newly purchased plants for 4-6 months to allow them to acclimate to new surroundings. Re-pot when overcrowded (about every 3-4 years). Grow in bright, indirect light or under fluorescent lights (14 hours per day) with night temperatures of 50-55 degrees and day temperatures of 70-75 degrees Fahrenheit. Plants will, however, tolerate 45-85 degrees easily.
INSECTS: Aphids, Mealy Bug, Scale: Use an approved insecticidesuch as Malathion.
DISEASES: Crown Gall: Destroy infected plants. Control disease with Malathion.
Leaf Spot: Spray with Bordeaux Mixture, Captan, Fermate. Destroy infected leaves.
Blight: Collect and burn fallen needles. Prune out and burn dead twigs. Water during drought. Fertilize trees in fall or early spring. Spray new growth when the candles are 1/4″ emerged. Repeat 2, 4, 6 weeks later with Zineb, Maneb, or Bordeaux Mixture.
PROPAGATION: Cuttings, air layering, seeds.
Every year on Norfolk Island the Norfolk Island Pine tree produces pine cones. Once the cones start to mature on the tree they break up and the seed floats to the ground.
When I had my Kentia Palm seedling export business on Norfolk Island I would annually receive enquiries from Dutch growers for consignments of Norfolk Island Pine seedlings.
To ascertain whether we would be able to fulfill their orders, we had to determine whether the viability of the seed that had dropped from the trees was sufficient for us to proceed economically, and obtain a financial return.
Norfolk Island Pines are scattered all over Norfolk Island , but not every tree produces annual seed that has a viability germination rate exceeding 60%.
To determine whether seed was viable we would pick up ten seeds from under a tree where seed had begun to drop. We would cut the seeds in half, and count how many seeds had a milky substance in the middle. This substance would tell us that the seed was viable. If the count was 6 or more we would proceed to pick the seed up and take that seed back to the nursery for planting.
There are two ways to plant Norfolk Island Pine seed. You can just scattered it on top of a potting mixture, and cover it with the same medium about 1/2 inch deep. The other way is to stick the pointy end of the seed into the medium, and lightly cover it with the medium leaving a small part of the seed exposed.
Germination of the seed will take place after about four weeks. It takes about ten weeks to have a seedling six inches tall ready for export. At that stage seedlings are carefully sifted, washed and counted into lots of 25 and bound with a rubber band. The seedlings are packed in shipping boxes, freighted to the mainland, and then reconsigned to the Dutch buyer.
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Cook pines (Araucaria columnaris) showing the natural pruning of lateral branches in deep shade. The whorls of lateral branches (appearing as bumps on the tree trunks) produce the striking knots in furniture and bowls made from this wood. Cook pines are native to New Caledonia and were introduced throughout the Hawaiian Islands.
The slender, spirelike crowns of Cook pine (Araucaria columnaris) form a striking contrast with the rugged mountains of Kauai, Hawaii. Cooks pines are native to New Caledonia and were introduced throughout the Hawaiian islands.
The araucaria family (Araucariaceae) contains three remarkable genera of cone-bearing trees: Araucaria, Agathis and Wollemia. They are tall trees native to forested regions of South America and Australia. In majestic size and beauty, they certainly rival the coniferous forests of North America and Eurasia. In fact, they are considered the southern counterpart of our northern pine forests. The type genus Araucaria is derived from “Arauco,” a region in central Chile where the Araucani Indians live. This is also the land of the “monkey puzzle” tree (A. araucana), so named because the prickly, tangled branches would be difficult for a monkey to climb. Fossil evidence indicates that ancestral araucaria forests resembling the present-day monkey puzzle date back to the age of dinosaurs. In fact, it has been suggested that the tree’s armor of daggerlike leaves was designed to discourage enormous South American herbivorous dinosaurs, such as Argentinosaurus weighing an estimated 80 to 100 tons! Another ancient South American species called pino paraná or paraná pine (A. angustifolia) grows in southern Brazil and Argentina.
A South American monkey puzzle tree (Araucaria araucana). The prickly, tangled branches would probably be difficult (and painful) for a monkey to climb. Fossil evidence indicates that ancestral araucaria forests resembling the present-day monkey puzzle date back to the age of dinosaurs.
Close-up view of the dense, sharp-pointed leaves of the monkey puzzle tree (Araucaria araucana). This species does not grow well in southern California, but forms beautiful specimen trees in the Pacific northwest and England. An ancestral species formed extensive forests in Europe during the Jurassic Period, about 150 million years ago.
A monkey puzzle tree (Araucaria araucana) in the hot Sacramento Valley of northern California. The photograph was taken at Bidwell Park in Chico. Although this species does not grow well in arid southern California, it is occasionally planted in parks and gardens of northern California. It grows much better in colder climates of Oregon and Washington with more rainfall.
Australian members of the Araucariaceae include the prickly-leaved bunya-bunya (A. bidwillii) with huge pineapple-shaped cones, the hoop pine (A. cunninghamii) an important Australian timber tree, the Cook pine (A. columnaris) native to New Caledonia, and the Norfolk Island pine (A. heterophylla) native to Norfolk Island. The latter species is commonly grown in containers in southern California and is sold as “star pine” because of its horizontal tiers of radiating limbs. Throughout San Diego County “star pines” can easily be recognized by their tall, slender spires of tiered limbs. This species was discovered by Captain James Cook during his second voyage to Australia and New Zealand (1772-1775). The closely related Cook pine of New Caledonia that is naturalized throughout the Hawaiian Islands is named after this famous English explorer. Like the Norfolk Island pine, the bunya-bunya has an unmistakable silhouette with its barren, horizontal limbs tufted at the ends with spiny leaves. The huge seed cones of tall trees pose a serious threat to unsuspecting persons sitting beneath its cone-laden limbs.
An Australian bunya-bunya tree (Araucaria bidwillii) growing in a park in Carlsbad, California (San Diego County). The seed cones of this species are larger than pineapples and pose a serious threat to unsuspecting persons sitting beneath the cone-laden limbs.
What does a bunya-bunya seed cone have in common with a ripe pineapple? They are both heavy and could cause injury if dropped on an unprotected head from a distance of 75 feet (23 m). Unlike bunya-bunya cones, pineapples do not drop from the limbs of tall trees.
At Quail Botanical Garden in Encinitas (San Diego County) the trail
near the bunya-bunya trees is closed during August and September.
Bunya-bunya (Araucaria bidwillii) seed cone (left) and Coulter pine (Pinus coulteri) seed cone (right), two of the largest cones produced by cone-bearing trees (division Coniferophyta). Green bunya-bunya cones typically weigh 10 pounds (4.5 kg) or more. Green, unopened Coulter pine cones typically weigh 5 to 8 pounds (up to 3.6 kg). Cones of both species can be harmful if they fall from the upper branches of mature trees and hit your unprotected head.
A large bunya-bunya seed cone that has just hit the ground at the San Diego Wild Animal Park. Note the ovuliferous scale or megasporophyll (white arrow) bearing a single large seed on its upper surface.
An ovuliferous scale (megasporophyll) and several large seeds from a bunya-bunya cone. Each scale bears one seed on its upper surface. The lower right seed has been removed from its woody seed coat. The nutritious seeds were harvested and eaten by Australian Aborigines.
Left: A bunya-bunya tree in Santa Barbara, California. This Australian conifer has an unmistakable silhouette with its barren, horizontal limbs tufted at the ends with spiny leaves. Right: Resinous sap oozing out of the trunk of a large bunya-bunya.
Also in the araucaria family is the genus Agathis with more than a dozen species of large, resinous trees scattered throughout Australia, New Zealand and the Malay Archipelago. Several species of Agathis are the source of timber and valuable copal varnish, including kauri pine (A. australis), amboina pine (A. dammara) and dammar pine or Queensland kauri (A. robusta). Copals are a group of resins that form particularly hard varnishes. In addition to Agathis, there are New World sources of copal from resinous leguminous trees, including the West Indian locust (Hymenaea courbaril) and several species of Copaifera. Dammars are another group of hard, durable varnishes that turn shiny and transparent when dry. Although some species of Agathis are named dammar, most dammar resins come from tropical Asian trees of the genus Shorea in the Diptocarpaceae. Copals and dammars are used extensively in oil paintings. When painting with oils, colored pigment is squeezed onto a palette and then taken up in a thinning solution of linseed oil mixed with either copal or dammar. The resins “hold” the paint when dry and provide the luminous depth characteristic.
In 1994, David Noble discovered an unknown cone-bearing tree in rugged Wollemi National Park northwest of Sydney, Australia. About 40 trees in deep narrow canyon turned out to be an undescribed species. They were named Wollemi pine (Wollemia nobilis), a remarkable new member of the Araucariaceae. This rare conifer was thought to be extinct because its last fossil record was dated at about two million years ago. Choroplast DNA studies show no discernable genetic variation among the 40 trees. Like the rare Torrey pine (Pinus torreyana) of San Diego County, this is truly a relict population that was more widespread millions of years ago. Because of its small population size, a lot of its genetic diversity has been lost through thousands of years of isolation. The Wollemi pine is a great botanical discovery and is truly a “living fossil.” Trees are being propagated from seeds, and who knows, maybe some day this tree will be cultivated in San Diego County like other living fossils such as the maidenhair tree (Ginkgo biloba) and dawn redwood (Metasequoia glyptostroboides).
Left: A cone-bearing branch from the Norfolk Island pine (Araucaria heterophylla), a close relative of the Cook pine (A. columnaris). The branches of both species are densely clothed with small, overlapping, triangular leaves. Right: A cone-bearing branch from the dammar pine or Queensland kauri (Agathis robusta), another interesting Australian member of the Araucariaceae. The leaves of this species are unusual among conifers because they are broad-leaved rather than needlelike or scalelike.
Although they are often referred to as pines, members of the araucaria family have seed cones and foliage that is very different from the pine family (Pinaceae). Conifers in the pine family have cone scales with a pair of ovules (seeds) on the upper surface. Each cone scale is subtended by a distinct bract which is conspicuously exerted in some California species, such as the Douglas fir (Pseudotsuga menziesii) and Santa Lucia fir (Abies bracteata). Members of the araucaria family have only one ovule per scale and have bracts that are fused to the scale or none. Unlike the long, slender needles of pines (Pinus), araucarian leaves are typically short, overlapping and often prickly. Some species have broad leaves that superficially resemble leaves of flowering plants. In their native habitats, the araucarias become tall timber trees up to 200 ft. (61 m).
View of upper (adaxial) surface of the seed-bearing scales from female (ovulate) cones of the Australian bunya-bunya (Araucaria bidwillii) and the southern California Coulter pine (Pinus coulteri). The araucaria scale has a single large seed, while the pine scale bears a pair of winged seeds. Cones from both of these species can be very large, weighing up to ten pounds or more. Araucaria cones fall apart at maturity, so you don’t tend to find old, intact cones on the ground beneath the trees.
Close-up view between the scales of a large female cone from a Coulter pine (Pinus coulteri). Each scale bears two winged seeds on its upper (adaxial) surface. Each pine scale is also subtended by a woody bract (not shown in this photo). In some genera of the pine family (Pinaceae), such as Pseudotsuga menziesii (Douglas fir) and Abies bracteata (Santa Lucia fir), the subtending bracts are conspicuously exerted. Araucaria cones have only one seed that is fused to the scale.
See The Exerted Bracts Of Santa Lucia Fir
Branchlets of three South Pacific species of Araucaria native to Norfolk Island and Australia. Although they are called “pines,” they do not belong to the pine family (Pinaceae). Unlike the slender needles of pines, araucarian leaves are quite variable depending on the species. Top: Norfolk Island pine (A. heterophylla) with dense, overlapping, awl-shaped leaves. Middle: Hoop pine (A. cunninghamii) with flattened, needlelike leaves. Bottom: Bunya-bunya pine (A. bidwillii) with broad, sharp-pointed leaves.
Fossil evidence indicates that the araucaria family reached its maximum diversity during the Jurassic and Cretaceous periods between 200 and 65 million years ago, with worldwide distributions. At the end of the Cretaceous, when dinosaurs became extinct, so did the Araucariaceae in the northern hemisphere. Until about 135 million years ago, trees of the Araucariaceae grew in forests of the southern supercontinent called Gondwanaland, when South America and Africa were connected with each other and with Anarctica, India and Australia. By 65 million years ago, the continents had divided into positions resembling their present-day configuration. During this time interval, araucariads began a slow decline in range and diversity as flowering plants, better adapted to climatic changes, began to evolve and gradually displace conifers.
Petrified Forest National Park in northeastern Arizona contains hundreds of acres of perfectly preserved logs from an ancient conifer forest that dates back to the late Triassic Period (approximately 225 million years ago). The trees of this forest coexisted with dinosaurs. Most of the petrified logs were previously assigned to the extinct species Araucarioxylon arizonicum, a presumed distant relative of Araucaria; however, new evidence indicates that these fascinating deposits of petrified logs represent a broad diversity of conifer species. Streams carried dead logs into this once swampy lowland region where they were buried in sediments rich in volcanic ash. Over countless centuries, the woody tissue has been replaced by minerals and gradually turned into stone. These ancient trees flourished during a time when all of the continents were united into the vast supercontinent Pangea. The area of Petrified National Park was located near the equator, at approximately the latitude of present-day Central America. Many of the reddish, agatized logs do not show cellular detail; however, there are some permineralized specimens in which minerals permeated the porous cell walls and filled the cell cavities (lumens). Thin sections of these samples viewed under a microscope show remarkable cellular detail.
Petrified wood fragments in northern Arizona near Cameron. These are probably from the Chinle Formation dating back to the Triassic Period, approximately 200 million years ago.
End view of one of the above wood fragments in its natural state. It was not altered (sectioned or polished). The fine grain structure shows perfectly preserved tracheids viewed in a transverse (cross section) plane. This wood predates the larger vessels characteristic of angiosperms. Photo taken with a hand held Nikon D-90 and SB 400 Flash using a 60mm Micro Nikkor AF-S F/2.8G ED Macro Lens. Camera settings: ISO 200, F22, 1/200. The high density, thick-walled tracheids and parallel rays resemble some of the images in the Online Publication by Dr. Rodney A. Savidge (2007), particularly the genera Pullisilvaxylon and Chinleoxylon (previously listed under Araucarioxylon arizonicum).
Note: The average diameter of one tracheid cell lumen in cross section is about 30-40 µm. The resolving power of an unaided human eye with 20-20 vision is about 70 µm. Therefore, the cellular detail in above wood fragment is invisible to the naked eye.
- Savidge, R.A. 2007. “Wood Anatomy of Late Triassic Trees in Petrified Forest National Park, Arizona, USA, in Relation to Araucarioxylon arizonicum Knowlton, 1889.” Bulletin of Geosciences 82 (4): 301-328.
Cross section of petrified wood fragment from Cameron, Arizona compared with a modern pine stem. Both stem cross sections show two spring growth periods with larger tracheids separated by a narrower summer growth band with smaller tracheids. The petrified wood dates back to the Triassic Period, approximately 220 million years ago.
Left: Vessels in midvein of petal from Brodiaea terrestris ssp. kernensis. The spirally-thickened secondary cell walls appear like coiled springs. This provides strength as well as flexibility to these strands of tubular, water-conducting cells that compose the xylem (vascular) tissue. Right: Two types of water-conducting cells: tracheid and vessel (vessel element). Technically a vessel is composed of many hollow vessel elements joined end-to-end like sections of PVC pipe. With the exception of the Gnetophyta, most gymnosperms lack vessels. Vessels are characteristic of all flowering plants, except for the earliest ancestral sister clade (Amborella) that have only tracheids like most gymnosperms.
Although the binomial Araucarioxylon arizonicum has been used in the literature for more than a century, Rodney A. Savidge of the University of New Brunswick (Bulletin of Geosciences Vol. 82 No. 4: 301-328, 2007) states that it is superfluous and therefore an illegitimate name (nomen superfluum). He examined thin sections of the original three specimens (syntypes) housed at the Smithsonian Institute upon which the species was first described by F.H. Knowlton in 1889. He concluded that they represented different species within two new genera of extinct trees. According to the International Code of Botanical Nomenclature, a valid species can have only one type specimen or holotype. Consequently, only one of the three specimens was retained as the new type or lectotype Pullisilvaxylon arizonicum. Savidge examined several other logs previously identified as A. arizonicum and concluded that they also represented additional new genera and species. His extensive anatomical studies indicate that the majority of logs at Petrified Forest National Park do not belong to a single species. It appears that the superfluous name “A. arizonicum” actually refers to a complex of extinct conifers. Based solely on the tracheid structure of permineralized wood (including resin canals, rays and tracheid pitting), and without DNA evidence, it is difficult to be certain which trees in the complex are ancestral relatives of the araucaria family. According to Dr. Savidge (personal communication, 2008), an immense amount of research into petrified woods is needed before the ancestries leading to modern trees will be clearly understood. At this time it would be purely conjectural to assign a scientific name to most logs in Petrified Forest National Park without detailed microscopic examination of the wood.
Trees of “Araucarioxylon arizonicum” grew to a height 200 feet (61 m) with a trunk diameter from 4 to 9 feet. According to Sidney R. Ash and Geoffrey T. Creber (Paleontology Vol. 43 No. 1: 15-28, 2003), the living tree did not closely resemble any of the present-day Araucaria trees of the southern hemisphere as postulated in past reconstructions. The branches did not occur in whorls as they do in most conifers, instead they grew irregularly along the trunk. Sydney Ash and Rodney Savidge also studied the bark anatomy of Araucarioxylon arizonicum (“The Bark of Late Triassic Araucarioxylon arizonicum from Petrified Forest National Park, Arizona,” IAWA Journal 25 No. 3: 349-368, 2004), and concluded that it was quite unlike the banded bark of extant Araucaria heterophylla. These ancient conifers grew in a tropical rain forest with marshes and river lakes, in an environment very different from today’s Arizona landscape.
Petrified Forest National Park in Arizona contains hundreds of acres of perfectly preserved logs from an ancient tropical flood plain during the late Triassic Period (over 200 million years ago). The trees of this extinct forest coexisted with dinosaurs. Many of the petrified logs have been assigned to the genus Araucarioxylon, a presumed distant relative of Araucaria; however, new evidence indicates that these petrified logs represent a broad diversity of conifer species. Streams carried dead logs into this once swampy lowland region where they were buried in sediments rich in volcanic ash. The woody tissue of the logs became impregnated with minerals such as silica and gradually turned into stone.
Trees of the “Araucarioxylon arizonicum” grew to a height 200 feet (61 m) with a trunk diameter from 4 to 9 feet. According to Sidney R. Ash and Geoffrey T. Creber (Paleontology Vol. 43 No. 1: 15-28, 2003), the living tree did not closely resemble any of the present-day Araucaria trees of the southern hemisphere as postulated in past reconstructions. These ancient conifers grew in a tropical region with marshes and river lakes, an environment very different from today’s Arizona landscape.