Difference between revisions of "Araucaria heterophylla"

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{{Taxobox
 
{{Taxobox
 
| color = lightgreen
 
| color = lightgreen
| name = ''Saintpaulia''
+
| name = ''Araucaria heterophylla''
| image = Purple_African_Violet_Top.JPG
+
| status = VU
 +
| status_system = iucn2.3
 +
| image = Norfolkpine001.jpg
 
| image_width = 240px
 
| image_width = 240px
| image_caption = a ''Saintpaulia ionantha'' cultivar
+
| image_caption = Young Norfolk Island Pines
| regnum = [[Plant]]ae
+
| regnum = [[Plantae]]
| divisio = [[Flowering plant|Magnoliophyta]]
+
| divisio = [[Pinophyta]]
| classis = [[Magnoliopsida]]
+
| classis = [[Pinophyta|Pinopsida]]
| ordo = [[Lamiales]]
+
| ordo = [[Pinales]]
| familia = [[Gesneriaceae]]
+
| familia = [[Araucariaceae]]
| genus = '''''Saintpaulia''''' [[Johann Christoph Wendland|J.C.Wendl.]]
+
| genus = ''[[Araucaria]]''
| subdivision_ranks = Species
+
| species = ''A. heterophylla''
| subdivision =  
+
| binomial = ''Araucaria heterophylla''
''[[Saintpaulia brevipilosa]]''<br/>
+
| binomial_authority = ([[Richard Anthony Salisbury|Salisb.]]) Franco
''[[Saintpaulia confusa]]''<br/>
 
''[[Saintpaulia difficilis]]''<br/>
 
''[[Saintpaulia diplotricha]]''<br/>
 
''[[Saintpaulia goetzeana]]''<br/>
 
''[[Saintpaulia grandifolia]]''<br/>
 
''[[Saintpaulia grotei]]''<br/>
 
''[[Saintpaulia inconspicua]]''<br/>
 
''[[Saintpaulia intermedia]]''<br/>
 
''[[Saintpaulia ionantha]]''<br/>
 
''[[Saintpaulia magungensis]]''<br/>
 
''[[Saintpaulia nitida]]''<br/>
 
''[[Saintpaulia orbicularis]]''<br/>
 
''[[Saintpaulia pendula]]''<br/>
 
''[[Saintpaulia pusilla]]''<br/>
 
''[[Saintpaulia rupicola]]''<br/>
 
''[[Saintpaulia shumensis]]''<br/>
 
''[[Saintpaulia teitensis]]''<br/>
 
''[[Saintpaulia tongwensis]]''<br/>
 
''[[Saintpaulia velutina]]''
 
 
}}
 
}}
 +
[[Image:AraucariaHfoliage.jpg|left|thumb|220px|''Araucaria heterophylla'' foliage from a mature tree]]
 +
'''''Araucaria heterophylla''''' (synonym ''A. excelsa'') is a distinctive [[Pinophyta|conifer]], a member of the ancient and now disjointly distributed family [[Araucariaceae]]. As its vernacular name '''Norfolk Island Pine''' implies, the tree is [[endemic (ecology)|endemic]] to [[Norfolk Island]], though it is not a [[pine]]. The genus [[Araucaria]] occurs across the South Pacific, especially concentrated in [[New Caledonia]] (about 700 km due north of Norfolk Island) where 13 closely related and similar-appearing species are found. The trees grow to a height of 50-65 m, with straight vertical trunks and symmetrical branches, even in the face of incessant onshore winds that can contort most other species.
  
'''''Saintpaulia''''' is a genus of 20 species of [[herbaceous]] [[perennial plant|perennial]] [[flowering plant]]s in the family [[Gesneriaceae]], native to [[Tanzania]] and adjacent southeastern [[Kenya]] in eastern tropical [[Africa]], with a concentration of species in the [[Nguru mountains]] of Tanzania. The genus is most closely related to ''[[Streptocarpus]]'', with recent phylogenetic studies suggesting it has evolved directly from subgenus ''Streptocarpella''.  Common names include '''Saintpaulia''', '''African-violet''' or '''African Violet''', the latter somewhat confusing name given due to its superficial resemblance to true [[Violet (plant)|violet]]s (''Viola'', family [[Violaceae]]).
+
The [[leaf|leaves]] are awl-shaped, 1-1.5 cm long, about 1 mm thick at the base on young trees, and incurved, 5-10 mm long and variably 2-4 mm broad on older trees, the thickest, scale-like leaves on coning branches in the upper crown. The [[conifer cone|cones]] are squat globose, 10-12 cm long and 12-14 cm diameter, and take about 18 months to mature. They disintegrate at maturity to release the [[nut (fruit)|nut]]-like edible [[seed]]s.  
  
The genus is named after [[Baron Walter von Saint Paul Illaire]], the district commissioner of [[Tanga Province|Tanga]] province who discovered the plant in [[Tanganyika]] (now [[Tanzania]]) in [[Africa]] in [[1892]] and sent seeds back to his father, an amateur botanist in [[Germany]].  Two British plant enthusiasts, Sir John Kirk and Reverend W.E. Taylor, had earlier collected and submitted specimens to [[Royal Botanic Gardens, Kew]] in [[1884]] and [[1887]] respectively, but the quality of specimens was insufficient to permit scientific description at that time.  The genus ''Saintpaulia'', and original species ''S. ionantha'', were officially described by [[Johann Christoph Wendland|J.C. Wendland]] in 1893.
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The scientific name ''heterophylla'' ("different leaves") derives from the variation in the leaves between young and adult plants.
  
Saintpaulias grow from 6-15 cm tall and can be anywhere from 6-30 cm wide. The [[leaf|leaves]] are rounded to oval, 2.5-8.5 cm long with a 2-10 cm petiole, finely hairy, and with a fleshy texture. The [[flower]]s are 2-3 cm diameter, with a five-lobed velvety corolla ("petals"), and grow in clusters of 3-10 or more on slender stalks (peduncles). Flower colour in the wild species varies between [[Violet (color)|violet]], [[purple]], pale [[blue]] and [[white]].
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==Cultivation and uses==
 +
Its distinctive appearance, with widely spaced branches and a symmetrical, triangular outline, has made it a popular cultivated species, either as a single tree or in avenues. When the tree reaches maturity, the shape may become less symmetrical. As well as in its native Norfolk Island, it is widely planted in [[Australia]], [[New Zealand]], [[Florida]], [[Hawaii]], [[South Africa]] and southern [[California]].  
  
Several of the species are [[endangered species|endangered]], and many more are threatened, due to clearance of their native [[cloud forest]] habitat for [[agriculture]].  
+
It grows well in deep sand, as long as it receives reliable water when young. This, and its tolerance of salt and wind, makes it ideal for coastal situations.  
  
===Cultivation===
+
[[Image:AraucariaHeterophyllaAK.jpg|thumb|left|220px|Mature Norfolk Island Pine in Auckland, New Zealand]]
[[Image:Pink_African_Violet.jpg|thumb|left|A pink, double-flowered cultivar]]
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Young trees are often grown as houseplants in areas where the winters are too cold for them to grow outside (they will not, for example, survive outdoors in most of the [[United States]] or [[Europe]], but are sometimes used as [[Christmas tree]]s there, as elsewhere). Some people may experience a strong [[allergic]] reaction if they touch the leaves. The timber is good for [[woodturning]], and is extensively used by Hawaiian craftspeople. However, British explorer [[James Cook]] unsuccessfully used these trees as ship masts when exploring Norfolk Island. Large numbers of Norfolk Island Pines are produced in South Florida for the [[houseplant]] industry. The bulk of these are shipped to grocery stores, discount retailers and garden centers during November. Many of these are sprayed with a light coating of green paint prior to sale to increase their eye appeal.
Saintpaulias are widely cultivated as [[house plant]]s. Until recently, only a few of these species have been used in breeding programs for the hybrids available in the market; most available as house plants are [[cultivar]]s derived from ''Saintpaulia ionantha'' (syn. ''S. kewensis''). A wider range of species is now being looked at as sources of genes to introduce into modern cultivars.  
 
  
Over 2,000 cultivars have been selected for [[horticulture|horticultural]] use. There are many different leaf and flower types found; cultivars are classified as Large, Standard, Trailing, Semi-mini, Mini, and Micro with Micro being the smallest. They range in flower colour from white, pink, violet, yellow, and some even green, and the flowers may be either single (five petals) or double (more
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In Florida, these trees are subject to [[frost]] damage and as a result produce multiple stems with weakly attached trunks. In the [[2004]] [[hurricane]] season, many of these trees failed under the 160 km/h winds. Some coastal communities (e.g. Vero Beach) prohibit their use as a tree in local landscape plan approvals.
than five, with some or all of the [[stamen]]s converted into extra petals).  Flowers are not always a solid colour, but can also be found in the "fantasy" variety where the petals have strips of colours going down them. One interesting flower form found in the African Violet are known as a "wasp"; these flowers have the upper two flower petals independently fused forming a tube. There are also compound leaves on some, that are called "bustled".
 
  
Saintpaulias can be propagated by leaf [[Cutting (plant)|cutting]]s (essential for propagating named cultivars) or seed (from which new cultivars are selected). African violets prefer a constant temperature between 20-25°C with high humidity, and thrive best planted in well-drained [[humus]] or [[coir]] compost. Saintpaulias should be watered from underneath, and misting should be avoided, as water coming in contact with the leaves can cause damage.
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In the US it is sometimes called a star pine, due to its symetrical shape as a sapling.
  
Some popular cultivars include 'Amazen Grace', 'Blue Border', 'Claret Queen', 'Dupont Blue', 'Ding Dong Trail', 'Glacier', 'Little Jewel', 'Mini Marina', 'Pink Miracle', and 'Porcelain'.
+
==References and external links==
 +
* {{IUCN2006|assessors=Conifer Specialist Group|year=1998|id=30497|title=Araucaria heterophylla|downloaded=11 May 2006}} Listed as Vulnerable (VU B1+2c v2
 +
.3)
 +
*[http://www.conifers.org/ar/ar/heterophylla.htm Gymnosperm Database: ''Araucaria heterophylla'']
  
==Plant diseases==
+
{{Commons|Araucaria heterophylla}}
  
{{Main|List of African violet diseases}}
+
[[Category:Araucariaceae]]
 
+
[[Category:Flora of Norfolk Island]]
===External links===
 
*[http://www.avsa.org African Violet Society of America website]
 
*[http://avsc.ca African Violet Society of Canada website]
 
*[http://www.saintpauliasallskapet.se Swedish African Violet Society website]
 
*[http://www.saintpaulia.fi Finnish Saintpaulia Society website]
 
*[http://gesneriads.ca/saintart.htm Gesneriad Reference Web Saintpaulia article]
 
 
 
[[Category:Gesneriaceae]]
 
[[Category:Garden plants]]
 
[[Category:Flowers]]
 

Latest revision as of 06:39, 28 March 2007

Araucaria heterophylla
VU
Young Norfolk Island Pines
Young Norfolk Island Pines
Plant Info
Scientific classification
Kingdom: Plantae
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Araucariaceae
Genus: Araucaria
Species: A. heterophylla

Binomial name
Araucaria heterophylla
(Salisb.) Franco
Araucaria heterophylla foliage from a mature tree

Araucaria heterophylla (synonym A. excelsa) is a distinctive conifer, a member of the ancient and now disjointly distributed family Araucariaceae. As its vernacular name Norfolk Island Pine implies, the tree is endemic to Norfolk Island, though it is not a pine. The genus Araucaria occurs across the South Pacific, especially concentrated in New Caledonia (about 700 km due north of Norfolk Island) where 13 closely related and similar-appearing species are found. The trees grow to a height of 50-65 m, with straight vertical trunks and symmetrical branches, even in the face of incessant onshore winds that can contort most other species.

The leaves are awl-shaped, 1-1.5 cm long, about 1 mm thick at the base on young trees, and incurved, 5-10 mm long and variably 2-4 mm broad on older trees, the thickest, scale-like leaves on coning branches in the upper crown. The cones are squat globose, 10-12 cm long and 12-14 cm diameter, and take about 18 months to mature. They disintegrate at maturity to release the nut-like edible seeds.

The scientific name heterophylla ("different leaves") derives from the variation in the leaves between young and adult plants.

Cultivation and uses

Its distinctive appearance, with widely spaced branches and a symmetrical, triangular outline, has made it a popular cultivated species, either as a single tree or in avenues. When the tree reaches maturity, the shape may become less symmetrical. As well as in its native Norfolk Island, it is widely planted in Australia, New Zealand, Florida, Hawaii, South Africa and southern California.

It grows well in deep sand, as long as it receives reliable water when young. This, and its tolerance of salt and wind, makes it ideal for coastal situations.

Mature Norfolk Island Pine in Auckland, New Zealand

Young trees are often grown as houseplants in areas where the winters are too cold for them to grow outside (they will not, for example, survive outdoors in most of the United States or Europe, but are sometimes used as Christmas trees there, as elsewhere). Some people may experience a strong allergic reaction if they touch the leaves. The timber is good for woodturning, and is extensively used by Hawaiian craftspeople. However, British explorer James Cook unsuccessfully used these trees as ship masts when exploring Norfolk Island. Large numbers of Norfolk Island Pines are produced in South Florida for the houseplant industry. The bulk of these are shipped to grocery stores, discount retailers and garden centers during November. Many of these are sprayed with a light coating of green paint prior to sale to increase their eye appeal.

In Florida, these trees are subject to frost damage and as a result produce multiple stems with weakly attached trunks. In the 2004 hurricane season, many of these trees failed under the 160 km/h winds. Some coastal communities (e.g. Vero Beach) prohibit their use as a tree in local landscape plan approvals.

In the US it is sometimes called a star pine, due to its symetrical shape as a sapling.

References and external links

.3)

Template:Commons