Northern banksia facts for kids
Quick facts for kids Northern banksia |
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Banksia integrifolia subsp. aquilonia (A.S.George) K.R.Thiele |
The Banksia aquilonia, also known as the northern banksia or jingana, is a type of tree. It belongs to the plant family called Proteaceae. This tree is special because it only grows in northern Queensland, Australia.
It usually grows to about 8 meters (26 feet) tall. Some have even been recorded at 15 meters (49 feet) tall! Its leaves are shiny green and narrow, up to 20 centimeters (8 inches) long. In autumn, it produces pale yellow flower spikes. These spikes are called inflorescences. After the flowers fall off, the spikes develop up to 50 seed pods, called follicles. Each follicle holds two seeds.
A scientist named Alex George first described this plant in 1981. He first thought it was a type of Banksia integrifolia. Later, he decided it was its own separate species. Studies of its genes show it is related to other banksia species like Banksia plagiocarpa and Banksia oblongifolia. The northern banksia grows in wet sclerophyll forests and at the edges of rainforests. It prefers sandy soils. After a bushfire, this banksia can regrow from special buds under its bark. People do not often grow this plant in gardens.
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What the Northern Banksia Looks Like
The Banksia aquilonia is a tall shrub or small tree. It can grow up to 8 meters (26 feet) high. Some plants have even reached 15 meters (49 feet). It has hard, grey bark with cracks. Its leaves are long and narrow, like a spearhead. They are 5 to 20 centimeters (2 to 8 inches) long and 0.6 to 1.2 centimeters (0.2 to 0.5 inches) wide. The edges of the leaves are smooth. They have pointed tips.
The top of the leaves is smooth and shiny green. The underside is white with a clear midrib. This midrib is covered in reddish-brown hairs. New brownish leaves appear in summer. The plant blooms from March to June.
Flower Spikes and Seeds
The flowers grow in a special vertical spike, which is typical for banksias. This spike is an inflorescence. It has hundreds of flower pairs packed closely in a spiral. The flower spike of B. aquilonia is pale yellow. It is about 6 to 10 centimeters (2.4 to 3.9 inches) tall and up to 6 centimeters (2.4 inches) wide.
Each tiny flower has a tube-shaped part called a perianth. These are about 2.5 to 2.9 centimeters (1.0 to 1.1 inches) long. When the flowers are ready, their styles pop out. After the flowers are gone, up to 50 oval-shaped seed pods, or follicles, grow on the woody spike.
These follicles are 0.8 to 1.2 centimeters (0.3 to 0.5 inches) long. They are furry at first but become smooth as they get older. When they are ripe, they open up. Their two halves split to release one or two seeds. The seeds are dark grey-brown to black and are shaped like an egg. They are about 1.4 to 1.6 centimeters (0.6 inches) long. Each seed has a woody separator next to it.
Young Banksia aquilonia plants have bright green seed leaves, called cotyledons. These are about 1 centimeter (0.4 inches) long. The first true leaves are narrower than adult leaves. They are 7 to 24 centimeters (2.8 to 9.4 inches) long. They often have jagged or "toothed" edges.
How it Differs from Other Banksias
The flower spikes of Banksia aquilonia look similar to those of Banksia integrifolia. However, their leaves are quite different. The underside of B. aquilonia leaves has a distinct midrib covered in short reddish-brown hairs. Also, its leaves are arranged in a spiral pattern on the branches. This is different from B. integrifolia, where leaves grow in rings.
These differences led Alex George to classify B. aquilonia as a separate species. The overall shape of the Banksia aquilonia tree is similar to B. integrifolia, but it is usually smaller. The northernmost B. integrifolia plants are about 200 kilometers (120 miles) away from the southernmost B. aquilonia plants. This distance helps in telling them apart.
How Scientists Classify the Northern Banksia
Alex George first described Banksia aquilonia in 1981. He called it a variety of Banksia integrifolia. He collected a sample of the plant in Crystal Creek National Park in Queensland. The name aquilonia comes from a Latin word meaning "northern." This was because it was the most northern type of B. integrifolia known at the time.
In 1996, scientists Kevin Thiele and Pauline Ladiges studied how banksia species are related. They used a method called cladistic analysis. They noticed that B. aquilonia was different from other B. integrifolia plants. It was different both in its looks and where it grew. They thought it should be its own species.
Later in 1996, Alex George officially changed its classification. He made it a full species because of its unique leaf arrangement and midrib. So, its full scientific name is Banksia aquilonia (A.S.George) A.S.George.
Scientists group Banksia aquilonia within the Banksia genus. It is in the subgenus Banksia, section Banksia, and series Salicinae. This series includes other banksias like Banksia dentata and Banksia plagiocarpa.
More recent studies using DNA have looked at the relationships between banksia species. These studies suggest that Banksia aquilonia is more closely related to B. plagiocarpa, B. oblongifolia, and B. robur. It seems less related to B. integrifolia than previously thought.
The common names for this plant include northern banksia, white banksia, honeysuckle, or white bottlebrush. The local Aboriginal people, the Jirrbal and Girramay people, call it jingana.
Where the Northern Banksia Lives
The Banksia aquilonia grows in coastal areas of northern Queensland. Its range stretches from Cedar Bay National Park to Paluma Range National Park. This area gets a lot of rain, from 1000 to 4000 millimeters (39 to 157 inches) each year.
You can find it from near sea level up to 1000 meters (3,300 feet) high. It lives in many different places. These include wet sclerophyll forests or the edges of rainforests. It grows on plateaus, ridges, slopes, and low-lying swampy areas. It prefers sandy or rocky soils, often from granite. Sometimes it grows in clay.
It often grows alongside other trees. These include pink bloodwood (Corymbia intermedia) and forest red gum (Eucalyptus tereticornis). It also grows with swamp turpentine (Lophostemon suaveolens) and forest oak (Allocasuarina torulosa). Smaller plants like coin spot wattle (Acacia cincinnata) grow beneath it. Much of its natural home in the Wet Tropics has been damaged or broken up.
How the Northern Banksia Interacts with Nature
The Banksia aquilonia can regrow after a bushfire. It does this from special buds under its bark, called epicormic buds. It has also been seen regrowing from its roots. Unlike many banksia species that release their seeds after fires, Banksia aquilonia releases its seeds when its follicles are mature.
Banksia flowers are full of energy-rich food. The nectar from B. aquilonia is likely a food source for the endangered mahogany glider (Petaurus gracilis). Many other mammals and birds also feed on it. Birds seen visiting the flower spikes include the bridled honeyeater and the rainbow lorikeet.
Growing the Northern Banksia
The Banksia aquilonia can grow well in gardens. It prefers places with humid or mild climates. However, it is not commonly grown. It grows quickly. It can grow in acidic soils with a pH from 3.5 to 6.5.
Most often, new plants are grown from seeds. Plants grown from seed will flower when they are about four to six years old. You can also grow new plants from cuttings. These should be semi-hardened branches about the thickness of a pencil. The flower spikes attract birds to a garden. You can also grow it in a pot. If grown in a pot, its branches should be pruned often to keep the leaves thick and bushy.
See also
In Spanish: Banksia aquilonia para niños
